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PROGRESS REPORT - ENEA - Fusione

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<strong>PROGRESS</strong> <strong>REPORT</strong><br />

2006<br />

Nuclear Fusion and Fission, and Related Technologies Department<br />

ITALIAN NATIONAL AGENCY FOR NEW TECHNOLOGIES ENERGY<br />

AND THE ENVIRONMENT


This report was prepared by the Scientific Publications Office from contributions provided by the scientific and<br />

technical staff of <strong>ENEA</strong>’s Nuclear Fusion and Fission, and Related Technologies Department.<br />

Scientific editors: Paola Batistoni, Adriana Romagnoli, Gregorio Vlad<br />

Design and composition: Marisa Cecchini, Lucilla Crescentini, Lucilla Ghezzi<br />

Artwork: Flavio Miglietta<br />

English revision: Carolyn Kent<br />

See http://www.fusione.enea.it for copy of this report<br />

Cover picture: The six BNC cables and<br />

Piccolo–Micromegas assemby inside the TRIGA<br />

reactor<br />

Published by:<br />

<strong>ENEA</strong> - Nucleo di Agenzia<br />

Edizioni Scientifiche,<br />

Centro Ricerche Frascati,<br />

C.P. 65<br />

00044 Frascati, Rome (Italy)<br />

Tel: +39(06)9400 5016<br />

Fax: +39(06)9400 5015<br />

e-mail: cecchini@frascati.enea.it


A FUSION PROGRAMME 6<br />

Contents<br />

A1 MAGNETIC CONFINEMENT 6<br />

Introduction 6<br />

A1.2 FTU Facility 7<br />

A1.3 Experimental Results 8<br />

Lower hybrid current drive studies in ITER-density-relevant plasmas 8<br />

Liquid lithium limiter experiment 10<br />

MHD real-time control experiment 12<br />

Electron cyclotron current drive experiment 12<br />

Disruption studies 13<br />

Dusty plasmas 14<br />

A1.4 Plasma Theory 16<br />

Theory of beta-induced Alfvén-eigenmodes 17<br />

Electron fishbones: theory and experimental evidence 17<br />

Analysis and modelling of LHW propagation in toroidal plasmas<br />

by asymptotic methods 18<br />

Modelling of the ICRH experiment on JET 19<br />

Simulation of burning plasma dynamics by ICRH accelerated minority ions 20<br />

Particle simulation of bursting Alfvén modes in JT–60U 21<br />

Theory of Alfvén waves and energetic particle physics in burning plasmas 23<br />

Nonlinear equilibria, stability and generation of zonal structures in toroidal plasmas 23<br />

A1.5 JET Collaboration 24<br />

Participation in the JET EP/EP2 24<br />

Participation in experimental campaigns C15-C17 26<br />

A1.6 Proto–Sphera 29<br />

A2 PRELIMINARY DESIGN OF FT3 32<br />

Introduction 32<br />

A2.2 Scientific Motivation of the Proposal 33<br />

A2.3 Preliminary Design Description 36<br />

A3 TECHNOLOGY PROGRAMME 40<br />

Introduction 40<br />

A3.2 Divertor, First Wall, Vacuum Vessel and Shield 40<br />

Manufacturing of small-scale W monoblock mockups 40<br />

Engineering Design Activities: V and VI test campaigns 42<br />

Hydraulic characterisation of full-scale divertor components 42<br />

H permeation through EUROFER and heat exchanger material (Incoloy, Inconel) 43<br />

Formal trials for the new ITER divertor cassette refurbishment 43<br />

A3.3 Breeder Blanket and Fuel Cycle 44<br />

DEMO breeding blanket 44<br />

European Breeding Blanket Test Facility 44<br />

Thermo-mechanical characterisation of HCPB mockup 44<br />

TRIEX loop for studying technologies for extracting tritium from Pb-17Li 46<br />

Conceptual design of auxiliary systems for HCPB-TBM 46<br />

Structural analyses during em loading 46<br />

VDS catalyst tests 47<br />

Permeator tubes 48


Contents<br />

A3.4 Magnet and Power Supply 48<br />

ITER magnet casing welds 48<br />

ITER pre-compression ring fibreglass composite material 48<br />

High-frequency/high-voltage solid-state modulator for ITER gyrotrons 48<br />

A3.5 Remote Handling and Metrology 48<br />

A3.6 Neutronics 50<br />

Quality assurance for neutronics analysis for ITER 50<br />

ITER systems: nuclear design 51<br />

TBM HCPB and HCLL neutronics experiments 51<br />

Experimental validation of neutron cross sections for fusion-relevant materials 52<br />

A3.7 Materials 53<br />

Flat-top indenter for mechanical characterisation 53<br />

A3.8 IFMIF 54<br />

Remote handling of the back-plate bayonet concept – bolted solution 54<br />

Lithium corrosion and chemistry: LIFUS III facility 54<br />

Preliminary remote handling handbook for IFMIF facilities 55<br />

Inventories and dose rates induced by deuterons and neutrons in<br />

the accelerator system 56<br />

Inventories and dose rates induced by deuterons and neutrons in<br />

the cooling system 56<br />

A3.9 Safety and Environment, Power Plant Studies and Socioeconomics 56<br />

Failure mode and effect analysis for the European test blanket modules 56<br />

Failure mode and effect analysis for remote handling transfer systems of ITER 57<br />

Validation of computer codes and models 57<br />

Dust removal experiments in STARDUST 58<br />

Feasibility study of a torus-shaped facility for dust mobilisation studies 58<br />

Post-accident occupational exposure and radioprotection 58<br />

Integration of design modifications (in Rapport Préliminaire de Sûreté)<br />

to tritium building and detritiation system 59<br />

Collection and assessment of data related to JET occupational<br />

radiation exposure 60<br />

JET data collection on malfunctions and failures of ICRH system components 60<br />

JET dust in-vitro experiment: result assessment and in-vivo experiment<br />

literature review 60<br />

Study on recycling of fusion activated material 61<br />

A4 SUPERCONDUCTIVITY 62<br />

Introduction 62<br />

A4.2 ITER and ITER-Related Activities 62<br />

ITER toroidal field cable conductor 62<br />

Current redistribution study on ITER conductors 64<br />

EFDA dipole 64<br />

Barrel bending experiments 65<br />

Optimisation of NbTi strand for PF1/PF6 performance 65<br />

A4.3 JT-60SA 66<br />

A4.4 High–Temperature Superconducting Materials 66<br />

Evolution and control of cube texture in Ni-W substrates for YBCO-coated<br />

conductors 66<br />

Nickel-copper alloys as textured substrates for YBCO–coated conductors 68<br />

MOD-TFA YBCO films 69


Introduction of artificial pinning sites in YBCO films 70<br />

Magnetic characterisation of superconducting wires for fast ramped<br />

superconducting dipoles 71<br />

MARIMBO experiment: application of MgB 2 72<br />

Transport and thermal stability characterisation of HTS wires and tapes:<br />

analysis of quench propagation on YBCO-coated conductors 73<br />

A5 INERTIAL FUSION 74<br />

A6 PUBLICATIONS, PATENTS AND EVENTS 78<br />

A6.1 Publications 78<br />

Articles 78<br />

Articles in course of publication 81<br />

Contributions to conferences 82<br />

Reports 86<br />

A6.2 Patents 86<br />

A6.3 Conferences and Events 87<br />

A6.4 Seminars 87<br />

B FISSION TECHNOLOGY 88<br />

B1 R&D ON NUCLEAR FISSION 88<br />

B1.1 Innovative Fuel Cycles Including Partitioning and<br />

Transmutation 88<br />

Partitioning technology 88<br />

Transmutation systems and related technology 90<br />

VELLA - Virtual European Lead Laboratory 102<br />

B1.2 Evolutionary and Innovative Reactors 102<br />

International Reactor Innovative and Secure 103<br />

European Lead-Cooled Fast System 104<br />

Very high temperature reactor 106<br />

B1.3 Nuclear Safety 107<br />

Code validation and accident analysis 107<br />

Severe accident analysis 109<br />

Reliability and risk analysis 111<br />

B1.4 Nuclear Data 112<br />

General quantum mechanics 112<br />

Nuclear reaction theory and experiments 113<br />

Nuclear data processing and validation 113<br />

Computer code development 115<br />

Radioactive ion-beam production for nuclear-structure studies 116<br />

B1.5 TRIGA RC-1 and RSV TAPIRO Plant-Operation for Application<br />

Development 117<br />

B2 MEDICAL, ENERGETIC AND ENVIRONMENTAL APPLICATIONS 118<br />

B2.1 Boron Neutron Capture Therapy 118<br />

The epithermal column EPIMED at TAPIRO 118<br />

Employment of the thermal column HYTHOR at TAPIRO 121


Study of BNCT applied to lung tumours 121<br />

Design of a facility at TRIGA to treat explanted livers 122<br />

B2.2 Solar Thermal Energy 123<br />

B2.3 Development Activities for Antarctic Drilling 124<br />

B3<br />

PARTICIPATION IN INTERNATIONAL WORKING GROUPS<br />

AND ASSOCIATIONS 128<br />

B4 PUBLICATIONS 130<br />

B4.1 Publications 130<br />

Articles 130<br />

Reports 133<br />

Contributions to conferences 134<br />

C NUCLEAR PROTECTION 140<br />

C1 RADIOACTIVE WASTE MANAGEMENT AND ADVANCED<br />

NUCLEAR FUEL CYCLE TECHNOLOGIES 140<br />

Introduction 140<br />

C1.2 Entrustment of <strong>ENEA</strong>’s Fuel Cycle Facilities and<br />

Personnel to Sogin 140<br />

C1.3 Characterisation, Treatment and Conditioning of Nuclear<br />

Materials and Radioactive Waste 140<br />

C1.4 Radioprotection and Human Health 142<br />

Methodological proposal for the evaluation of a physiological comfort<br />

index in indoor environments 142<br />

LCA of strippable coating and the principal competing technology<br />

used for nuclear decontamination 143<br />

C1.5 Integrated Service for Non-Energy Radwaste 143<br />

C1.6 Transport of Nuclear Material 144<br />

Packaging for transport of radioactive material 144<br />

C1.7 Disposal of Radioactive Waste 145<br />

Artificial barriers for disposal units 145<br />

D MISCELLANEOUS 146<br />

D1 Advances in the IGNITOR Programme 146<br />

D2 Ultra-Pure Hydrogen Production 147<br />

D3 Non-ITER Activities 148<br />

D4 Condensed Matter Nuclear Science 149<br />

ORGANISATION CHART 152<br />

ABBREVIATIONS AND ACRONYMS 154


Preface<br />

This report describes the research activity carried out<br />

during 2006 by the laboratories belonging to the <strong>ENEA</strong><br />

Nuclear Fusion and Fission, and Related Technologies<br />

Department (Dipartimento <strong>Fusione</strong>, Teconologie e<br />

Presidio Nucleari (FPN)).<br />

An important point to note is that during 2006 <strong>ENEA</strong><br />

implemented a new organisation that combines fusion<br />

and fission activities in the same department FPN. This<br />

choice is clearly advantageous for both fields.<br />

In the fusion field, a historical event took place in 2006 -<br />

the signature of the agreement for the construction of<br />

ITER in Europe (Cadarache). ITER concentrates the efforts<br />

of the most advanced countries in the world in utilizing fusion as a safe, environmentally sustainable<br />

and inexhaustible energy source. The participants in this challenging enterprise are Europe, China,<br />

Korea, India, Japan, the Russian Federation and the United States.<br />

<strong>ENEA</strong>, in the framework of the Euratom-<strong>ENEA</strong> Association for fusion, continues to contribute to<br />

broadening plasma physics knowledge as well as to developing the relevant technologies. This<br />

report describes the 2006 research activities carried out by the <strong>ENEA</strong> Fusion Research Group of the<br />

FPN with the contributions of other <strong>ENEA</strong> research groups. The following fields were addressed:<br />

magnetically confined nuclear fusion (physics and technology), superconductivity and inertial<br />

fusion.<br />

During 2006 the scientific activity at the Frascati Tokamak Upgrade (FTU) was focussed on ITERrelevant<br />

aspects of plasma scenarios. In the meantime the conceptual design activity and a report<br />

discussing the scientific motivation of the FT3 device in the context of the European Accompanying<br />

Programme were completed. This new proposal also involves the other participants in the <strong>ENEA</strong>-<br />

Euratom Association, namely, the Reversed Field Pinch Experiment (RFX) Consortium and the<br />

National Research Council (CNR) Milan. The technological R&D programme was performed in the<br />

ITER framework and under the Broader Approach Agreement with Japan. Collaboration with<br />

industry in view of the participation in construction of ITER was further strengthened.<br />

In the fission field one of the most important events at international level was the Global Nuclear<br />

Energy Partnership (GNEP), launched by the USA Government. The GNEP is a comprehensive<br />

strategy aimed at making it possible to use economical, environmentally responsible nuclear energy<br />

to meet growing electricity demand worldwide, while virtually eliminating the risk of nuclear material<br />

misuse. This initiative, together with the Generation-IV projects and the 6th European Union<br />

Framework Plan, is the reference frame in which the <strong>ENEA</strong> FPN Department operated during 2006<br />

in the nuclear fission field.<br />

<strong>ENEA</strong> benefits from a wide range of collaborations with other international research centres and<br />

with industry. Several patents were granted in 2006 and spin-off activities are in progress. High-tech<br />

services are supplied to Italian industry.<br />

The work summarised in this report is amply documented in published articles and conference<br />

communications (most of which invited).<br />

Frascati, December 2006<br />

Alberto Renieri


A1 Magnetic Confinement<br />

A Fusion Programme<br />

Scientific activity at the Frascati Tokamak Upgrade (FTU) continued to be focussed on ITER-relevant<br />

aspects of plasma scenarios. Reliable plasma operations with lithizated walls were achieved thanks to the<br />

newly installed liquid lithium limiter (LLL). A new experimental activity on dust creation/mobilisation was also<br />

started. Good results have been obtained although the 2006 experimental activity was somewhat limited.<br />

The spring campaign was first delayed by lightening hitting the electrical substation and then shortened<br />

because of an optical window cracking due to focus deterioration of the laser beam of the Thomson<br />

scattering diagnostic. Including a short autumn campaign, the whole 2006 experimental activity fully<br />

dedicated only 27 days to scientific programmes, out of a total of 50 operational days.<br />

The objective to push the performance of the wide (r/a ≥ 0.6, with r the radial coordinate and a the minor<br />

radius of the torus) internal transport barriers (ITBs) obtained in 2005 was not pursued in 2006 because of<br />

limited availability of lower hybrid (LH) power, necessary for controlling the current profile at higher plasma<br />

current and density. Experiments and studies were concentrated on ion transport in the presence of electron<br />

ITBs with ion heating determined by electron-ion collisional energy transfer.<br />

The LLL installed in 2005 allowed operations with extremely clean plasmas where the content of heavy Z<br />

impurities, typical of FTU metallic operations, was close to zero. In these conditions, discharges exhibit<br />

better confinement (~20% above ITER-97L), comparable with results obtained with freshly boronized walls.<br />

With the LLL acting as the main limiter new regimes exhibiting peaked density profile, up to density limit<br />

values, were found.<br />

Experiments dedicated to magnetohydrodynamic (MHD) control were aimed at improving m=2 mode<br />

stabilisation by modulating the electron cyclotron (EC) power in phase with the island rotation and at<br />

enhancing the signal-to-noise ratio to better identify the electron cyclotron heating (ECH) absorption<br />

position. Disruptions (induced by impurity injection and the density limit) were mitigated by electron<br />

cyclotron resonance heating (ECRH) power and were completely avoided when the power deposition<br />

coincided with the location of the modes responsible for the disruptions.<br />

Theoretical and experimental activities concerning dust in the plasma scrape-off layer (SOL) were<br />

successfully started in collaboration with the universities of Naples and Molise and with the Max Planck<br />

Institute for Extraterrestrial Physics. In the experimental work, in particular, evidence of dust particles<br />

collected in the SOL of FTU discharges was found on Langmuir probes.<br />

Mutual and positive feedbacks between theory and experiments led to i) clear identification of highfrequency<br />

MHD activity in FTU; ii) modelling of ion cyclotron resonance heating (ICRH) experiments on the<br />

Joint European Torus (JET); iii) numerical simulation of energetic ion transport and nonlinear Alfvénic<br />

fluctuations in situations of experimental relevance in present-day experiments, in the framework of a<br />

collaboration with the Japan Atomic Energy Research Institute (JAERI) JT-60U team.<br />

More basic activities were focused on electron-fishbone mode excitations by LH additional power, the<br />

propagation and absorption of radiofrequency (rf) waves in toroidal plasmas, the investigation of energetic<br />

ion dynamics in burning plasmas, and activities on plasma turbulence and turbulent transport.<br />

In 2006 the JET experimental campaigns were put off to July, and the participation of Frascati scientists was<br />

then limited to restart and high-level commissioning of the JET Enhancement Programme (EP) and the<br />

organisation of new enhancements for JET-EP2. The main experimental activity was resumed in autumn<br />

Progress Report 2006<br />

6


2006, with <strong>ENEA</strong> having direct responsibility for experiments both in Task Force S1, regarding hybrid scenarios with<br />

dominant electron heating, and in Task Force S2, on high-performance ITBs.<br />

The FT3 conceptual design activity and a report discussing the scientific motivation of the device in the context of<br />

the European programme were completed. Various plasma scenarios can be investigated and it is shown that the<br />

various heating systems are capable of producing the plasma conditions needed for the ITER physics investigation.<br />

The report includes a preliminary design of the machine, auxiliary heating systems and diagnostics, and a<br />

preliminary assessment of different sites and construction and operation costs.<br />

Finally, the construction of the poloidal field shaping coils of MULTI-PINCH (initial set-up of PROTO-SPHERA)<br />

continued during 2006 and will be completed by the beginning of 2007. The collaboration with the United Kingdom<br />

Atomic Energy Authority (UKAEA) continued, mainly on modelling and on experiments aimed at plasma start-up and<br />

plasma current ramp-up in the absence of the central solenoid in MAST.<br />

A1.2 FTU Facility<br />

During 2006 the FTU machine achieved 91% of successful pulses, continuing the high level of reliability of<br />

the previous years.<br />

Experimental work started at the end of March and continued up to the first week of July without<br />

suspensions. The second experimental session ran from mid-September to mid-October. In 2006, 1144<br />

shots were successfully completed out of a total of 1257 performed over 50 experimental days. The<br />

average number of successful daily pulses was 23.11. Table A1.I reports the main parameters for<br />

evaluating the efficiency of the experimental sessions. Figure A1.1 reporting the indicator trend from 1999<br />

up to 2006 shows that experimental time and successful pulses are stable, while experimental days are<br />

lower due to power supply problems and to a vacuum loss caused by a hole in the scattering window.<br />

For the control and data acquisition system:<br />

a) Work was started on developing a software framework to obtain a user-friendly environment for carrying<br />

out all the phases (i.e., control law design, simulation, automatic source code generation, debug and<br />

software release) related to the FTU real-time control system. A software simulation tool was also<br />

implemented and released. The whole work should be finished by 2007. A 10 PC Cluster has been<br />

installed to allow FTU data analysis in a Linux environment. In the initial phase the cluster is employed<br />

as a test-bed to characterise real-time network protocols suitable for ITER.<br />

b) A set of computing resources was released on the EGEE-GRID (i.e., Enabling Grids for E-sciencE) site<br />

of <strong>ENEA</strong> for the FUSION Virtual Organisation: in particular a 1-TB storage area is available for use by the<br />

Integrated Tokamak Modelling Task Force.<br />

c) A web tool was developed to handle the configuration of a data acquisition system (DAS) similar to the<br />

FTU control and data acquisition system (CODAS) and with the same data and parameter configuration.<br />

d) Work was started for a European Fusion Development Agreement (EFDA) task aimed at achieving a<br />

fully revised version of the ITER control data access and communication (CODAC) specifications ready<br />

for fusion internal review. In particular, <strong>ENEA</strong> has to revise the CODAC documentation, bringing it up to<br />

date for April 2007; prepare and organise internal and external reviews (including experts outside fusion)<br />

and a peer review of the CODAC design in agreement with the ITER International Team and ITER<br />

Participant Teams; incorporate into the CODAC design common proposals that will have to be<br />

discussed in the review process.<br />

To model the CODAC structure, the capabilities of UML language were studied. Preliminary results<br />

indicated that Matlab/Simulink could be suitable for the final design work, but a hybrid solution (UML code<br />

into Matlab/Simulink diagram) is being investigated.<br />

7<br />

Progress Report 2006


A1 Magnetic Confinement<br />

Table A1.I – Summary of FTU operations in 2006<br />

Jan. Feb. March April May June July Aug. Sept. Oct. Nov. Dec. Total<br />

A Fusion Programme<br />

Total pulses 0 0 103 130 268 385 0 0 120 251 0 0 1257<br />

Successful pulses (sp) 0 0 97 117 251 343 0 0 113 223 0 0 1144<br />

I(sp) 0.94 0.90 0.94 0.89 0.94 0.89 0.91<br />

Potential experimental days 0.0 0.0 8.0 11.0 10.5 17.0 4.0 0.0 12.0 8.5 0.0 0.0 71.0<br />

Real experimental days 0.0 0.0 4.0 6.5 10.5 15.5 0.0 0.0 4.5 8.5 0.0 0.0 49.5<br />

I(ed) 0.50 0.59 1.00 0.91 0.00 0.38 1.00 0.70<br />

Experimental minutes 0 0 1680 2136 4555 6294 0 0 2137 3913 0 0 20715<br />

Delay minutes 0 0 743 1888 1943 3098 0 0 815 1388 0 0 9875<br />

I(et) 0.69 0.53 0.70 0.67 0.72 0.74 0.68<br />

A(sp/d) 24.25 18.00 23.90 22.13 25.11 26.24 23.11<br />

A(p/d) 25.75 20.00 25.52 24.84 26.67 29.53 25.39<br />

Delay per system (minutes)<br />

Jan. Feb. March April May June July Aug. Sept. Oct. Nov. Dec. Total %<br />

Machine 0 0 24 89 104 266 0 0 98 148 0 0 729 7.4<br />

Power supplies 0 0 366 471 669 867 0 0 322 282 0 0 2977 30.1<br />

Radiofrequency 0 0 0 20 87 286 0 0 0 100 0 0 493 5.0<br />

Control system 0 0 16 17 158 352 0 0 89 120 0 0 752 7.6<br />

DAS 0 0 77 30 156 116 0 0 6 42 0 0 427 4.3<br />

Feedback 0 0 0 8 52 46 0 0 0 81 0 0 187 1.9<br />

Network 0 0 0 0 0 0 0 0 0 0 0 0 0 0.0<br />

Diagnostic systems 0 0 27 174 121 200 0 0 15 104 0 0 641 6.5<br />

Analysis 0 0 149 179 173 492 0 0 108 393 0 0 1494 15.1<br />

Others 0 0 84 900 423 473 0 0 177 118 0 0 2175 22.0<br />

TOTAL 0 0 743 1888 1943 3098 0 0 815 1388 0 0 9875 100<br />

Fig. A1.1 – Indicator trend from 1999 up to<br />

2006. I(sp): successful/total pulses. I(et):<br />

real/total experimental time. I(ed): real/total<br />

experimental days<br />

A1.3 Experimental Results<br />

Lower hybrid current drive studies in ITER-density-relevant plasmas<br />

The LH radiofrequency (f LH =8 GHz) heating system in FTU is used mainly to create and maintain<br />

radial profiles of the toroidal current j(r) that are suitable for sustaining plasma regimes with an ITB<br />

that improves core plasma confinement. The ECH radiofrequency system (f EC =140 GHz) facilitates<br />

this task, and the rf waves of both interact only with electrons. Ions are, instead, heated only via<br />

collisional damping of the hotter electrons. These regimes are currently the most valuable option for<br />

steady-state operation in ITER and future tokamak reactors. Indeed, the better confinement<br />

0.9<br />

0.7<br />

0.5<br />

I(ed)<br />

I(et)<br />

1999 2001 2003 2005<br />

Years<br />

I(sp)<br />

Progress Report 2006<br />

8


Fig. A1.2 – Ion thermal conductivity vs normalised minor radius, for the<br />

highest density a) and the widest b) steady ITB discharges. Experimental<br />

(χ i,exp ) and neoclassical (χ i,neo ) ion thermal conductivities are shown in<br />

full lines, while dotted segments limit the variability range during the<br />

whole ITB phase. Also shown are the ITB radial location and the ion<br />

thermal conductivity range during the Ohmic phase<br />

m 2 /s m 2 /s<br />

1<br />

0.5<br />

χ i,exp<br />

0<br />

χ<br />

1 i,neo<br />

0.5<br />

OH-exp<br />

OH-exp<br />

χ i,neo<br />

r ITB<br />

# 26671 highest n e<br />

# 27928<br />

b)<br />

widest radius<br />

r ITB<br />

a)<br />

obtained in ITB regimes would allow operation at a lower 0<br />

plasma current I p in order to obtain the same τ E with respect<br />

0 0.2 0.4 0.6<br />

r/a<br />

to the standard scenario. In addition, demands on the<br />

external current drive (CD) sources would be greatly reduced because the self-generated bootstrap current<br />

I bs would increase due both to the lower I p , and to the steeper pressure radial gradients arising in reduced<br />

transport conditions, I bs /I p ∝I p<br />

2·∇p.<br />

The peculiarity of FTU is that ITBs can be formed by using electron heating and current drive with no direct<br />

ion heating or external momentum injection, which is a similar condition to that foreseen for ITER. The<br />

additional capability to establish an ITB starting from a fully relaxed current profile at high density makes<br />

FTU unique. Unfortunately, in 2006 the LH and ECH performances were not at the level required for<br />

significant experimental progress, so activity in the ITB field was focussed mainly on exploiting at best the<br />

data previously obtained and on preparing the 2007 experiments.<br />

Crucial questions to be answered for ITER concern the effect collisional energy transfer between electron<br />

and ions has on ITBs and how electron ITBs, with little or no induced rotation, affect ion transport. Here<br />

the FTU contribution may be important and indeed the 2005 report illustrates the encouraging results on<br />

the first point, while ion transport has been treated recently in an overview of FTU results [A1.1] and in a<br />

more dedicated paper [A1.2]. Figures A1.2a) and A1.2b) plot the ion thermal conductivity χ i during an ITB<br />

as a function of radius for the two most representative steady discharges, one obtained at the highest<br />

density (fig. A1.2a)), and the other at the widest radius (fig. A1.2b)). The vertical bars limit the variability<br />

range of χ i during the ITB evolution phase. Irrespective of the ITB radius (r ITB ) χ i appears to drop below<br />

neoclassical at r≤r ITB . Although the magnitude of χ i,neo might be overestimated due to the uncertainty on<br />

the safety factor q(r), χ i,neo ∝q 2 , for two very different ITB discharges χ i drops just at the barrier footprint<br />

and falls even below the value it has in the Ohmic phase. This is of particular relevance since energy<br />

transport is usually faster if the temperature increases, while Ohmic temperatures are lower. Therefore a<br />

q(r) profile with low shear (which is typical of ITB regimes) appears suitable for reducing not only the<br />

electron but also the ion transport, without the support of induced plasma rotation. Although limited so far<br />

to low ion central temperature values T i0 this result is promising for ITER. Consistently, the drop in the<br />

turbulence level close to the barrier foot derives from decorrelation of the modes that could affect both<br />

electron and ion transport [A1.3, A1.4].<br />

The possible application of lower hybrid current drive (LHCD) to ITER, however, still has to satisfy the<br />

requirement of high efficiency η CD . Previous FTU results [A1.5] show that η CD does not degrade up to and<br />

χ i,exp<br />

[A1.1] V. Pericoli–Ridolfini et al., Proc. 21 st IAEA Fusion Energy Conference (Chengdu 2006), on line at: http://wwwnaweb.iaea.org/napc/physics/FEC/FEC2006/papers/OV_3-4.pdf,<br />

and submitted to Nuclear Fusion<br />

[A1.2] V. Pericoli–Ridolfini et al., Proc. 21 st IAEA Fusion Energy Conference (Chengdu 2006), on line at: http://wwwnaweb.iaea.org/napc/physics/FEC/FEC2006/papers/EX_P1-15.pdf<br />

[A1.3] V. Pericoli–Ridolfini et al., Plasma Phys. Control. Fusion 47, B285–B301 (2005)<br />

[A1.4] M. De Benedetti et al., Proc. 32 th EPS Conference on Plasma Physics (Tarragona 2005), on line at:<br />

http://epsppd.epfl.ch/Tarragona/pdf/P4_035.pdf<br />

[A1.5] V. Pericoli–Ridolfini et al., Nucl. Fusion 45, 1386-1395 (2005)<br />

References<br />

9<br />

Progress Report 2006


A1 Magnetic Confinement<br />

A Fusion Programme<br />

J LH (r) (arb. units)<br />

q(r)<br />

1<br />

0.8<br />

0.6<br />

0.4<br />

FRTC + scattering<br />

#27928, t=0.7s<br />

Hard-X ray<br />

(FEB)<br />

0.2<br />

FRTC - NO<br />

0<br />

scattering<br />

0 0.05 0.1 0.15 0.2 0.25 0.3<br />

r(m)<br />

10<br />

8<br />

6<br />

4<br />

2<br />

LHstar<br />

Conventional<br />

MSE<br />

0<br />

0 0.2 0.4 0.6 0.8 1<br />

r/a<br />

Fig. A1.4 – Safety factor profile q(r) vs normalised<br />

minor radius for a current-hole discharge of JET:<br />

comparison between LHCD radial profiles from<br />

experiment (MSE diagnostic, dashed line), from the<br />

recently developed LHstar code (full line) and from<br />

conventional calculation (dotted-dashed line)<br />

beyond the ITER density (line average<br />

n _ e =1×1020 m -3 ), while the favourable scaling of<br />

η CD with electron temperature T e leaves hope for<br />

the desired value >0.35×10 20 Am -2 /W. However,<br />

the lower ITER LH frequency (f LH,ITER =5 GHz)<br />

may induce some concern on the basis of the<br />

past results on ASDEX [A1.6] and JET [A1.7].<br />

The ratio of plasma to wave frequency (f pe /f LH ),<br />

which could be an important parameter, had to<br />

be f pe /f LH ≤15, while in ITER it will be ~18.<br />

Although f pe /f LH ≤15 in FTU, some precursors of<br />

efficiency loss started to appear: the frequency<br />

spectral broadening of the LH pump was no<br />

longer negligible, the main cause being the<br />

interaction of the LH waves with the edge<br />

plasma. Here, the low temperatures, even more<br />

than 100 times below the core, and the relatively<br />

high densities, larger than 0.1 times the core,<br />

can either exalt the linear scattering on density<br />

fluctuations or trigger nonlinear phenomena,<br />

such as parametric decay instability (PDI). Both<br />

effects, which however may also coexist, can<br />

cause noticeable degradation of the N ||<br />

spectrum and of the trajectories of the launched<br />

LH waves (N || is the parallel index of refraction<br />

and governs the LHCD efficiency).<br />

In this context both effects were modelled by considering the available data. For turbulent scattering<br />

in the SOL, the model follows the one proposed in [A1.8]. More details can be found in [A1.9]. For<br />

the scattering case, figure A1.3 reports a comparison of the LH power radial deposition derived from<br />

the fast electron bremsstrahlung (FEB) camera and the deposition according to the newly<br />

developed fast ray tracing code (FRTC) and to the conventional calculation [A1.10]: only when<br />

scattering is taken into account is there good agreement with the experiment. The case considered<br />

is the ITB discharge in figure A1.2b). For the PDI case figure A1.4 shows the fairly good agreement<br />

for JET between the q(r) profiles derived from the motional Stark effect (MSE) diagnostic and those<br />

calculated with the newly developed code LHstar [A1.11], which takes into account the nonlinear<br />

interaction LH waves-edge plasma. Conversely the agreement is a good deal poorer for the profile<br />

calculated conventionally.<br />

Liquid lithium limiter experiment<br />

Fig. A1.3 – Comparison between LHCD radial profiles in<br />

FTU computed by FRTC: LH wave edge scattering by<br />

density fluctuations (full line, FRTC+scattering), no<br />

scattering (dash-dotted line, FRTC-NO scattering), and the<br />

experiment (dashed line, same discharge as in fig. A1.2,<br />

hard x ray [FEB])<br />

During 2006, experiments to test a liquid lithium limiter with a capillary porous system (CPS)<br />

configuration on FTU [A1.12, A1.13] were continued and a full analysis of the first results obtained<br />

at the end of 2005 was performed. The programme in collaboration with TRINITI & Red Star<br />

(Russian Federation) was also begun: the aim is to investigate the behaviour of liquid lithium in view<br />

of its possible application as plasma-facing material and in the framework of a more general study<br />

on liquid metals. Lithium was chosen because of its low atomic number, good thermal properties<br />

Progress Report 2006<br />

10


Fig. A1.5 – Plasma viewed by a visible CCD camera. At the bottom a bright ring<br />

separated from the main toroidal limiter by a darker zone is clearly visible. LLL is<br />

located on the far bottom right, where the glow is most intense<br />

and strong capability to pump deuterium and impurity<br />

particles. The LLL, composed of three similar units with<br />

dimensions respectively of 100 mm and 34 mm in poloidal and<br />

toroidal directions has been inserted 1.0-2.0 cm within the<br />

SOL, from the bottom vertical port 1. It has been used for<br />

depositing a thin Li film on the FTU metallic walls during<br />

plasma discharge (lithization) and as a liquid material facing the<br />

plasma.<br />

Infrared and visible detectors viewing the LLL surface, plus Langmuir probes placed 5 mm from the LLL<br />

leading edge, have been used to determine surface temperature [A1.14], Li release, electron density and<br />

temperature in the SOL plasma at the LLL position. In 2006, experiments in Ohmic conditions confirmed<br />

the previous results [A1.15, A1.16]. Plasma discharges with heating power up to 0.85 MW are<br />

characterised by the lowest Z eff , P rad and D α signals (as monitor of particle recycling) ever observed on<br />

FTU, and whether the LLL is inserted or not inside the vacuum chamber makes no substantial difference.<br />

Strong modifications occur in the SOL [A1.15, A1.17] with respect to the standard metallic wall conditions.<br />

Electron temperature increases by more than ΔT e ,SOL~10 eV, due to the strong reduction in deuterium<br />

and impurity recycling together with the low radiation from Li atoms/ions eroded by the walls. When the<br />

LLL is inserted inside the vessel, instead, the liquid surface represents a strong localised source of Li<br />

atoms/ions, which increases radiation losses in a region that is close to the LLL poloidal location and<br />

toroidally uniform. Figure A1.5 shows a plasma image recorded by a visible CCD camera. The radiation in<br />

front of the LLL surface reduces the power flux onto the limiter surface which, in turn, is able to sustain<br />

thermal loads exceeding 5 MW/m 2 with no damage and no lithium bloom occurring. Thermal analysis with<br />

the ANSYS code together with the interpretation given in the framework of the 2D edge physics code<br />

TECXY [A1.18] support this view. Associated with the low particle recycling, enhanced performance<br />

operations, near or beyond the Greenwald limit, are easily obtained after lithization in the explored plasma<br />

current ranges (I p =0.5-0.9 MA), with no MHD activity. For I p =0.5 MA, B T =6T, the density limit<br />

(n _ e =2.7×1020 m -3 ) is 1.7 times higher than after a fresh boronization and a factor of 1.4 higher than the<br />

[A1.6] V. Pericoli–Ridolfini et al., Nucl. Fusion 34, 469-481 (1994)<br />

[A1.7] V. Pericoli–Ridolfini et al., Plasma Phys. Control. Fusion 39, 1115-1128 (1997)<br />

[A1.8] P.L. Andrews and F. Perkins, Phys. Fluids 26, 2537-2545 (1983)<br />

[A1.9] V. Pericoli–Ridolfini et al., Nucl. Fusion 38, 12, 1745-1755 (1998)<br />

[A1.10] G. Calabrò et al., Proc. 33 rd EPS Conference on Plasma Physics (Rome 2006), on line at: http://epsppd.epfl.ch/Roma/pdf/P5_077.pdf<br />

[A1.11] R. Cesario et al., Nucl. Fusion 46, 462-476 (2006)<br />

[A1.12] V.A. Evtikhin et al., Fusion Eng. Des. 56-57, 363-367 (2001)<br />

[A1.13] A. Vertkov et al., Technological aspects of liquid lithium limiter experiment on FTU tokamak, presented at the 24 th Symp. on Fusion<br />

Technology - SOFT, (Warsaw 2006)<br />

[A1.14] A.G. Alekseyev et al., Proc. 33 rd EPS Conference on Plasma Physics (Rome 2006), on line at:<br />

http://epsppd.epfl.ch/Roma/pdf/P1_162.pdf<br />

[A1.15] M.L. Apicella et al., First experiments with lithium limiter on FTU, presented at the 17 th Inter. Conference on Plasma Surface Interactions<br />

- PSI, (Hefei 2006), to appear in J. Nucl. Mater.<br />

[A1.16] G. Mazzitelli et al., Proc. 21 st Fusion Energy Conference (Chengdu 2006), on line at: http://wwwnaweb.iaea.org/napc/physics/FEC/FEC2006/papers/ex_p4-16.pdf<br />

[A1.17] V. Pericoli–Ridolfini et al., Modification of the SOL properties with the liquid lithium limiter in FTU - experiment and transport modeling,<br />

presented at the IEA Large Tokamak IA Workshop on Edge Transport in Fusion Plasmas - ETFP (Kraków 2006), to be published in<br />

Plasma Phys. Control. Fusion<br />

[A1.18] R. Zagórski and H. Gerhauser, Physica Scripta 70, 2/3, 173 (2004)<br />

References<br />

11<br />

Progress Report 2006


A1 Magnetic Confinement<br />

corresponding Greenwald limit. In this case the electron density profile reaches a very high peaking<br />

factor n e0 /=2.2 [A1.19] ( indicates the volume average).<br />

A Fusion Programme<br />

With the LLL well inserted in the SOL, peculiar new regimes are observed at high density<br />

(n _ e ≥1×1020 m -3 ) where, without particle fuelling, a spontaneous transition at higher n _ e occurs close<br />

to the Greenwald limit, characterised by peaked density profiles n e0 /2. This phenomenology,<br />

well described in [A1.17], is related to the high Li pumping rate that strongly depresses deuterium<br />

and impurity recycling, thus reducing to a great extent the instabilities due to multifaceted<br />

asymmetric radiation from the edge (Marfe).<br />

Transport and energy balance analysis was performed with the JETTO code for plasma discharges<br />

at I p =0.5 MA, n e =0.7×10 20 m -3 , B t =6 T after lithization, fresh boronization and with very clean<br />

metallic walls (e.g., oxygen-free) [A1.20]. An improvement in energy confinement time τ E by a factor<br />

of 1.3 was found for lithizated and boronized discharges compared to the metallic case, mainly due<br />

to the strong reduction in Ohmic power produced by the lower Z eff . For boronized and lithizated<br />

discharges τ E /τ ITER97L =1.25 was found, which is sensibly larger than the values observed for<br />

standard metallic FTU Ohmic discharges, which range between an average value of<br />

τ E /τ ITER97L =0.92 [A1.21] up to τ E /τ ITER97L =1.1 in the case of very good clean plasma.<br />

During 2006, preliminary operations with the LLL in plasma-heated discharges with LH and ECRH<br />

at power levels in the MW range were obtained without any particular problem, but careful analysis<br />

is required to gain a full physical and technological understanding of the experimental results.<br />

MHD real-time control experiment<br />

An active automatic system for MHD mode location and feedback control via ECRH power is<br />

installed on FTU. The system [A1.22, A1.23] is able to identify, in real time, mode presence/location<br />

and the position of ECRH absorption, and to proceed to suppress the mode.<br />

The aims of the 2006 campaign were i) to look for a more efficient m=2 mode stabilisation obtained<br />

by modulating the ECRH source in phase with the island rotation and ii) to optimise the technique<br />

for identifying the ECRH absorption position, by enhancing the signal-to-noise ratio.<br />

An overall experimental time of three days was allocated to the experiment: two during the spring<br />

campaign and one during the autumn campaign. Only a preliminary result [A1.24, A1.25] was<br />

obtained for target i) because of the difficulties found in plasma target production (an m=2 mode<br />

with rotation frequency less than 3 kHz): an MHD mode together with availability of the active ECRH<br />

system occurred only in a few shots, which were used to optimise the experimental setup. Various<br />

induced MHD production schemes and a Mo laser blow-off technique were tested. The<br />

achievement of a reliable target is still an open question in the experimental programme, and<br />

dedicated experiments should be planned. Further investigation is needed in order to close the<br />

control loop and complete the experiment.<br />

Regarding target ii), new modulation schemes were developed, using non-periodic ECRH<br />

modulation, to get a more enhanced signal-to-noise ratio and a better picking factor than with the<br />

usual fixed frequency modulation scheme. A partial power scan was performed, but a lower<br />

detectable power limit has still to be found [A1.26].<br />

Electron cyclotron current drive experiment<br />

The aim of the experiment was to explore at full EC power (1.5 MW) the capability of electron<br />

cyclotron current drive (ECCD) to modify the plasma current profile. Modifications would allow<br />

control of plasma core confinement and MHD instabilities (e.g., sawteeth) at ITER-relevant plasma<br />

density n (n=0.6–0.7×10 20 m -3 ) and magnetic field (B T =4.6–5.1 T).<br />

Progress Report 2006<br />

12


The immediate goal was to fix the minor radius range where local re-shaping of the plasma current density<br />

and safety factor q profiles can be modified by driving, with oblique injection of EC waves, well localised<br />

ECCD in co-/counter- directions (co, to reduce q, counter, to increase it). In the previous 2005 campaigns<br />

the range of minor radius was explored up to r/a=0.3, using 75% of the available EC power (1.1 MW).<br />

Significant non-inductive current for plasma current density re-shaping was obtained (6-7% I p ), and<br />

sawtooth stabilisation effects by local tailoring were observed by driving counter-current on-axis (±10°) in<br />

target plasmas with I p =360 kA, =0.75×10 20 m -3 and T e =5 keV [A1.27].<br />

In June 2006 one day of ECCD experiments (eight successful shots), with the same plasma conditions as<br />

in 2005, allowed better investigation of the radial range, stabilisation of sawteeth also at ±20° oblique EC<br />

injection, still using 75% of EC power. The goal to control the plasma current density in the plasma core,<br />

using two oblique injection angles (±10°–±20°), was achieved even though the ECCD was low (


A1 Magnetic Confinement<br />

Fig. A1.7 – P ECRH deposition scan: safety factor (q) values obtained from island viewed<br />

through soft-x-ray tomography (except for q=1 determined from sawtooth inversion radius)<br />

A Fusion Programme<br />

t dis -t MHD (ms)<br />

l/l p (%)<br />

80<br />

40<br />

# 29984<br />

q=1<br />

q=3/2 q=2<br />

40<br />

Another important issue is the effect of LH<br />

power on disruptions. The formation of large<br />

0<br />

runaway electron currents (fig. A1.8) has been<br />

0 40 80 120 160 found to occur more often in FTU in discharges<br />

(dl that disrupt during LH injection. Contrary to the<br />

p /dt) max (MA/s)<br />

theoretical expectations for electron thermal<br />

Fig. A1.9 – Runaway current fraction vs maximum runaway generation (based on the usual<br />

plasma current derivative during current quench for LH Dreicer and avalanche mechanisms), the<br />

runaway plateau disruptions. Ohmic runaway plateau largest runaway currents correspond to the<br />

disruptions included for comparison<br />

slowest plasma current decay rates (fig. A1.9).<br />

This trend is opposite to what is observed in<br />

most tokamaks. Such anomalous behaviour is<br />

attributed to pre-existent wave-resonant suprathermal electrons being accelerated during the<br />

disruption decay phase [A1.29]. These results could be relevant for the operation of ITER whenever<br />

a sizeable amount of LH power is used.<br />

Dusty plasmas<br />

# 29979 & # 29963<br />

q=3<br />

disruption<br />

avoidance<br />

0<br />

0 10 20<br />

r dep (cm)<br />

80<br />

350 kA;T e<br />

=80 eV<br />

LH -500 kA<br />

OH-500 kA<br />

350 kA;T e<br />

=44 eV<br />

LH - 350 kA<br />

OH- 300 - 400 kA<br />

500 kA;T e<br />

=42 eV<br />

Research on the problem of dust in tokamak plasmas is carried out in the framework of a<br />

collaboration with the universities of Naples and Molise and the Max Planck Institute for<br />

Extraterrestrial Studies. Interest in this subject is increasing due its relevance for fusion reactors in<br />

terms of safety and operation [A1.30].<br />

Preliminary theoretical studies were dedicated to analysing, in un-magnetised dusty plasmas,<br />

fundamental dust interactions and fluctuations. In the framework of linear, fluid theory, it was shown<br />

that over-screening and attraction between negatively charged dust particles can occur if cations<br />

are released by the dust surface [A1.31]. Problems associated with a full kinetic model of such dust<br />

interaction were discussed and solved in principle, although analytical calculations still have to be<br />

completed [A1.32]. The kinetic theory of fluctuations was used to describe changes in the spectral<br />

densities of plasma fluctuations in un-magnetised plasmas in the presence of dust [A1.33].<br />

n/s I p (MA)<br />

80<br />

0.4<br />

I p<br />

19989<br />

10 11 BF 3<br />

a)<br />

0.2<br />

0<br />

V I<br />

40<br />

0<br />

10 13<br />

b)<br />

NE213<br />

1.00 1.02 1.04 1.06 1.08<br />

Time (s)<br />

V I (V)<br />

Fig. A1.8 – Plasma disruption showing the formation of a<br />

0.3–MA runaway current: a) plasma current I p (solid) and<br />

loop voltage V loop (dashed); b) neutron rate: BF 3 (solid)<br />

and NE213 (dashed) signals. The NE213 line is absent<br />

during the plateau phase because of saturation<br />

Progress Report 2006<br />

14


Fig. A1.10 – Conditionally averaged signals with<br />

threshold of 4 a) and 8 rms b). Number of elementary<br />

charges collected during typical large event (inset in b)<br />

Experimental analysis of scattered laser light signals in FTU<br />

discharges during disruption events confirmed the presence of<br />

dust particles [A1.34], formerly observed by this kind of<br />

diagnostic in JIPPT-IIU [A1.35]. Laser scattering signals were<br />

observed by the Thomson scattering (TS) system installed in<br />

FTU. The spectral transmission of the filter of the spectral channel<br />

used for alignment has been centred at the laser wavelength so<br />

that it can reveal elastic light scattering, which might be due to<br />

the presence of dust particles [A1.35]. Elastic scattering<br />

observed in several discharges after a disruption can last more<br />

than 1 s after the end of the discharges. Preliminary analysis of<br />

the laser light scattering data suggests the presence, after a<br />

disruption, of sub-micron size (


A1 Magnetic Confinement<br />

A Fusion Programme<br />

probes, due to the impact of μm-sized<br />

dust at a velocity of the order of ten km/s.<br />

This interpretation is supported directly<br />

by electron microscope analysis of the<br />

probe surface, which revealed the<br />

presence of 10 to 100–μm–sized craters,<br />

a typical footprint of the impact ionization<br />

processes (fig. A1.11). A number of<br />

spherically shaped, iron-rich μm-sized<br />

particles was also observed to be<br />

embedded in the probe surface. Neither<br />

craters nor embedded particles were<br />

detected on the surface of the “virgin”<br />

probe. The size, number and distribution<br />

of the observed craters are consistent<br />

with impact ionization processes<br />

Fig. A1.11 – Electron microscope analysis of the probe occurring at an average rate of a few<br />

surface<br />

hundred Hz, which corresponds to<br />

10 4 m -3 density of fast μm–sized dust<br />

particles accelerated at velocities of the order of 10 km/s by ion drag forces associated with plasma<br />

flows in the SOL of FTU.<br />

A1.4 Plasma Theory<br />

Mutual and positive feedbacks between theory and experiments have led to a clear identification of<br />

high-frequency MHD activity (high frequency with respect to that typical of MHD fluctuations) in FTU<br />

as evidence of nonlinear Alfvén mode excitations by a large magnetic island.<br />

Electron-fishbone mode excitations by LH additional power only are explained within a general<br />

theoretical framework, which fully accounts for the various experimental evidence of such modes<br />

and also provides a simple yet relevant model for interpreting the rich nonlinear dynamic behaviour,<br />

observed experimentally.<br />

The theory of propagation and absorption of rf waves in toroidal plasmas has been explored in both<br />

its more basic aspects as well as with detailed applications of practical relevance, such as the<br />

modelling of ICRH experiments in JET and the investigation of burning plasma dynamics issues by<br />

ICRH accelerated minority ion supra-thermal tails.<br />

The investigation of energetic ion dynamics in burning plasmas has been articulated along three<br />

main lines: i) identification of the relevant plasma parameters that make it possible to experimentally<br />

study burning plasma physics issues in sub-ignited regimes; ii) numerical simulation of energetic ion<br />

transport and nonlinear Alfvénic fluctuations in situations of experimental relevance in present-day<br />

experiments; iii) first-principle-based analysis of fundamental processes involved in the collective<br />

excitation of Alfvénic modes and in the fluctuation enhanced energetic ion transport. Item ii) has<br />

been explored with the interpretation of nonlinear Alfvén wave dynamics and energetic ion transport<br />

observed in JT-60U by means of hybrid MHD-gyrokinetic numerical simulations, carried out within<br />

an ongoing collaboration with the Japan Atomic Energy Agency. For item iii) an overview of the<br />

theory of Alfvén waves and energetic particle physics in burning plasmas has been given as a result<br />

of work done within the continuing collaboration with University of California at Irvine (UCI) USA.<br />

Within the same framework of UCI collaboration, recent theoretical work on plasma turbulence and<br />

turbulent transport, or more specifically, on nonlinear equilibria, stability and generation of zonal<br />

structures in toroidal plasmas has been summarised.<br />

Progress Report 2006<br />

16


Theory of beta-induced Alfvén-eigenmodes<br />

Beta-induced Alfvén eigenmodes (BAEs) have frequency located in the low-frequency beta-induced gap in<br />

the shear-Alfvén continuous spectrum, which is caused by finite plasma compressibility [A1.38-A1.40].<br />

Their excitation can be due to the presence of fast ions and/or sharp thermal ion temperature gradients.<br />

However recent observations in FTU [A1.41, A1.42], TEXTOR [A1.43] and JET have revealed the presence<br />

of modes whose frequency is consistent with that of BAEs, coexisting with a large magnetic island, in the<br />

absence of fast ions and without direct thermal ion heating. In this framework, the magnetic island appears<br />

to play a causal role in the excitation of modes at BAE frequencies.<br />

A kinetic stability analysis [A1.40, A1.44] of BAEs, including the effects of finite Larmor radius, finite orbit<br />

width and toroidicity, led to a dispersion relation for BAE modes, obtained by asymptotically matching the<br />

kinetic layer solution with that of the ideal MHD region. The resulting frequencies compare very well with<br />

those seen experimentally in FTU [A1.45], so it can concluded that the modes observed are BAEs.<br />

Moreover, their calculated growth rates (the experimental ones cannot be measured) are negative but small<br />

in absolute value compared to their frequencies, so it can be inferred that such modes are marginally stable<br />

and become nonlinearly excited above a critical amplitude threshold of the magnetic island. Analysis of<br />

BAE destabilisation by a finite amplitude magnetic island is in progress.<br />

Electron fishbones: theory and experimental evidence<br />

The work described here was done in collaboration with UCI and the South-western Institute of Physics,<br />

Chengdu P.R.C. Fishbone-like internal kink instabilities driven by electrons in conjunction with ECRH on the<br />

high-field side were observed for the first time on DIII-D [A1.46]. The excitation was attributed to barely<br />

trapped supra-thermal electrons, which are characterised by drift-reversal and can destabilise a mode<br />

propagating in the ion diamagnetic direction in the presence of an inverted spatial gradient of the suprathermal<br />

tail. Similar but higher frequency modes were observed in Compass-D [A1.47] during ECRH and<br />

LH power injection, with chirping frequency comparable to that of the toroidal Alfvén eigenmode (TAE),<br />

[A1.48] ω≤ω TAE . Observations of electron fishbones with ECRH only [A1.49, A1.50] and LH only [A1.51,<br />

A1.52] have also been reported in HL-1M and FTU, respectively.<br />

[A1.38] W.W. Heidbrink et al., Phys. Rev. Lett. 71, 855 (1993)<br />

[A1.39] A.D. Turnbull et al., Phys. Fluids B5, 2546 (1993)<br />

[A1.40] F. Zonca, L. Chen and R.A. Santoro, Plasma Phys. Control. Fusion 38, 2011 (1996)<br />

[A1.41] P. Buratti et al., Nucl. Fusion 45, 1446 (2005)<br />

[A1.42] P. Buratti et al., Proc. 32 nd EPS Conference on Plasma Physics (Tarragona 2005), on line at:http: //epsppd.epfl.ch/Tarragona/pdf/<br />

P5_055.pdf<br />

[A1.43] O. Zimmermann et al., Proc. 32 nd EPS Conference on Plasma Physics (Tarragona 2005), on line at:http: //epsppd.epfl.ch/Tarragona/pdf/<br />

P4_059.pdf<br />

[A1.44] F. Zonca et al., Plasma Phys. Control. Fusion 40, 2009 (1998)<br />

[A1.45] S.V. Annibaldi, F. Zonca and P. Buratti, Proc. 33 rd EPS Conference on Plasma Physics (Rome 2006), on line at:http:<br />

//epsppd.epfl.ch/Roma/pdf/ O2_016.pdf, and to appear on Plasma Phys. Control. Fusion<br />

[A1.46] K.L. Wong et al., Phys. Rev. Lett. 85, 996 (2000)<br />

[A1.47] M. Valovic et al., Nucl. Fusion 40, 1569 (2000)<br />

[A1.48] C.Z. Cheng, L. Chen and M.S. Chance, Ann. Phys. 161, 21 (1985)<br />

[A1.49] X.T. Ding et al., Nucl. Fusion 42, 491 (2002)<br />

[A1.50] J. Li et al., Proc. 19 th IAEA Fusion Energy Conference (Lyon 2002), on line at: http://wwwpub.iaea.org/MTCD/publications/PDF/csp_019c/pdf/OV_5-1.pdf<br />

[A1.51] P. Smeulders et al., Proc. of the 29 th EPS Conference on Plasma Physics and Controlled Fusion (Montreaux 2002), on line at:<br />

http://epsppd.epfl.ch/Montreux/pdf/D5_016.pdf<br />

[A1.52] F. Romanelli et al., Proc. 19 th IAEA Fusion Energy Conf. (Lyon 2002), on line at: http://wwwpub.iaea.org/MTCD/publications/PDF/csp_019c/pdf/OV_4-5.pdf<br />

References<br />

17<br />

Progress Report 2006


A1 Magnetic Confinement<br />

A Fusion Programme<br />

keV MW 10 20 m -3 keV<br />

8<br />

1)<br />

6<br />

4<br />

T<br />

2 e0<br />

n 2)<br />

0.6 e,line<br />

0.5<br />

0.4<br />

1.5 P LH<br />

3)<br />

1.0<br />

0.5<br />

0<br />

0<br />

-0.5<br />

1<br />

-1<br />

st branch 2 nd branch ECE Ch 9 4)<br />

0.20 0.25 0.30 0.35 0.40<br />

Time (s)<br />

Fig. A1.12 – Time evolution of thermal electron temperature 1),<br />

electron density 2), LH power input 3) and (fast) electron<br />

temperature fluctuation 4) in FTU shot #20865. It is clear that<br />

the nonlinear behaviour of electron temperature fluctuations<br />

(electron fishbone) reflects the level of LH power input<br />

The peculiar features of electron fishbones were<br />

analysed vs those of the well-known ion fishbone<br />

[A1.53-A1.55]. Due to the frequency gap in the lowfrequency<br />

shear Alfvén continuum for modes<br />

propagating in the ion diamagnetic direction<br />

[A1.55], effective electron fishbone excitation<br />

favours conditions characterised by supra-thermal electron drift reversal, which is consistent with<br />

experimental observations. For the same reason, the spatial gradient inversion of the supra-thermal<br />

electron tail is necessary, explaining why ECRH excitation is observed with high-field side deposition<br />

only [A1.46, A1.49, A1.50, A1.56]. Circulating supra-thermal electrons play a peculiar role in electron<br />

fishbone excitations with LH only: the barely circulating population directly provides the mode drive<br />

and the well circulating particles controls the drift-reversal condition. As in the case of ion fishbones,<br />

two branches of the electron fishbone have been shown to exist: a discrete gap mode [A1.55] and<br />

a continuum resonant mode [A1.54]. Contrary to the gap mode, the continuum resonant mode can<br />

propagate in the electron diamagnetic direction as well. Thus, it does not require either drift-reversal<br />

or inverted spatial gradient of the supra-thermal electron tail. However, its threshold condition is<br />

higher and it requires high power densities to be excited. So, even the case of the continuum<br />

resonant fishbone mode tends to favour the branch propagating in the ion diamagnetic direction,<br />

which minimises continuum damping. If the effective temperature of the supra-thermal electron tail<br />

is sufficiently high, the present theory predicts that fishbone oscillations can be excited at<br />

frequencies comparable with those typical of the geodesic acoustic mode (GAM) [A1.57] or the BAE<br />

[A1.38, A1.39]. Unlike the case of fishbone gap modes in the ion diamagnetic gap [A1.55] of the<br />

low-frequency shear Alfvén continuum, fishbone gap modes in the BAE gap [A1.58] do not favour<br />

propagation in the ion diamagnetic direction, since the gap structure is nearly symmetric in<br />

frequency [A1.40]. One single general fishbone-like dispersion relation [A1.59] has been discussed,<br />

describing mode excitation by trapped as well as circulating supra-thermal electrons in both<br />

monotonic and reversed magnetic shear equilibria [A1.60].<br />

The most interesting feature of electron fishbones is their relevance to burning plasmas. In fact,<br />

unlike fast ions in present-day experiments, fast electrons are characterised by small orbits that do<br />

not introduce additional complications in the physics due to nonlocal behaviour, similarly to alpha<br />

particles in reactor-relevant conditions. Meanwhile, the bounce averaged dynamics of both trapped<br />

as well as barely circulating electrons depends on energy (not mass); hence their effect on lowfrequency<br />

MHD modes can be used to simulate/analyse the analogous effect of charged fusion<br />

products. Furthermore, the combined use of ECRH and LH provides extremely flexible tools to<br />

investigate diverse nonlinear behaviour, for which FTU experimental results provide a nice and clear<br />

example (fig. A1.12). During high-power LH injection, an evident transition in the electron fishbone<br />

signature takes place from almost steady-state nonlinear oscillations (fixed point) to regular bursty<br />

behaviour (limit cycle). A simple yet relevant nonlinear dynamic model has been derived for<br />

predicting and interpreting these observations [A1.61].<br />

Analysis and modelling of LHW propagation in toroidal plasmas by asymptotic<br />

methods<br />

The LH full wave equation in the electrostatic approximation and in general magnetic field equilibria<br />

has beenen critically analysed by applying asymptotic techniques when looking for the solution<br />

(Wenzel, Kramer, Brillouin [WKB] approximation). The phase and the amplitude were obtained<br />

numerically and analytically, and then compared [A1.62].<br />

Progress Report 2006<br />

18


Lower hybrid wave (LHW) propagation in a tokamak plasma 2D geometry can be correctly described only<br />

with a full wave approach based on full numerical techniques or on a semi-analytical approach, by reducing<br />

the wave equation into two nested equations of the first order, as shown in [A1.63]. To test and compare<br />

the full numerical solution with that obtained by applying the WKB asymptotic expansion, a rigorous WKB<br />

solution of the wave equation for the first two orders of the expansion parameter was presented, obtaining,<br />

at the first order, the equation for phase and, at the next order, the equation for the field amplitude. The<br />

nonlinear partial differential equation (PDE) for the phase was solved in a pseudo-toroidal geometry (circular<br />

and concentric magnetic surfaces) by the method of characteristics. The associated system of ordinary<br />

differential equations (ODEs) for the position and the wave-number was obtained and analytically solved<br />

by choosing an appropriate expansion parameter. The quasi-linear PDE for the WKB amplitude was also<br />

analytically solved, allowing reconstruction of the wave electric field inside the plasma. The solution was<br />

also obtained numerically and compared with the analytical solution. Further developments, consisting in<br />

generalising the solution to a Solov’ev analytical equilibrium geometry, are in progress. The validity of the<br />

WKB approximation was analysed on the basis of the results obtained.<br />

Modelling of the ICRH experiment on JET<br />

The aims of this modelling study are first to evaluate the main features of the proposed ICRH heating<br />

experiment and second to perform a detailed analysis of the experimental discharges. The proposed<br />

experiment concerns essentially the possibility of obtaining internal transport barriers (ITBs) on both the ion<br />

and the electrons species with only the use of the ICRH system in an ion-heating scheme, without neutral<br />

beam injection (NBI) as an external momentum input. In this context an ITB regime on JET was obtained<br />

by using 6 MW of ICRH in the minority heating scheme [A1.64].<br />

The minority species involved is 3 He. The scheme should act at the fundamental cyclotron harmonic of the<br />

minority species (ω=Ω cm ) located near the plasma centre, while the fundamental or the first harmonic of<br />

the majority (ω=Ω cM or ω=2Ω cM ) is out of the plasma. This is the so-called isolated case. Cyclotron<br />

resonance heating of the minority is very efficient because fast wave polarization is essentially determined<br />

by the majority species alone, while damping is due essentially to the resonant minority ions (minority<br />

heating regime). If the minority concentration increases too much, the screening due to the rotating electric<br />

field is no longer negligible, and cyclotron damping decreases drastically, entering the “mode conversion<br />

regime”.<br />

When programming an ICRH heating experiment, it is important to establish the plasma and antenna<br />

parameters that fit the goals well. In the ICRH minority heating experiment on JET, antenna and plasma<br />

parameters are chosen by maximising the power coupled to the plasma, without dealing with edge<br />

[A1.53] K. McGuire et al., Phys. Rev. Lett. 50, 891 (1983)<br />

[A1.54] L. Chen, R.B. White and M.N. Rosenbluth, Phys. Rev. Lett. 52, 1122 (1984)<br />

[A1.55] B. Coppi and F. Porcelli, Phys. Rev. Lett. 57, 2272 (1986)<br />

[A1.56] Z.-T. Wang et al., Chin. Phys. Lett. 23, 158 (2006)<br />

[A1.57] N. Winsor, J.L. Johnson and J.M. Dawson, Phys. Fluids 11, 2448 (1968)<br />

[A1.58] M.S. Chu et al., Phys. Fluids B4, 3713 (1992)<br />

[A1.59] F. Zonca and L. Chen, Plasma Phys. Control. Fusion 48, 537 (2006)<br />

[A1.60] R.J. Hastie et al., Phys. Fluids 30, 1756 (1987)<br />

[A1.61] F. Zonca et al., Electron fishbones: theory and experimental evidence, submitted to Nucl. Fusion<br />

[A1.62] A. Cardinali, L. Morini and F. Zonca, Proc. of the Joint Varenna-Lausanne International Workshop on Theory of Fusion Plasmas, ed. by<br />

J. Connor, O. Sauter, E. Sindoni (American Institute of Physics, Varenna), Vol. 871, 292 (2006)<br />

[A1.63] A. Cardinali and F. Zonca, Phys. Plasmas 10, 4199 (2003)<br />

[A1.64] F. Crisanti et al., Experimental evidence of ion internal transport barrier without injection of external momentum input, presented at the<br />

Transport Task Force Meeting (Varenna 2004)<br />

References<br />

19<br />

Progress Report 2006


A1 Magnetic Confinement<br />

cut–offs in the low field side, and by choosing the right minority concentration in order to avoid the<br />

mode conversion regime [A1.65].<br />

A Fusion Programme<br />

The following codes have been used to plan and to model the ICRH experiment:<br />

1) A code that solves the cold plasma electromagnetic (em) dispersion relation in slab geometry in<br />

order to clarify the dispersion characteristics of the experiment. Thus, the range of variation in<br />

the main parameters can be established, e.g., power spectrum vs plasma density profiles to<br />

assess the accessibility conditions; minority concentration to assess, in a plasma with two ion<br />

species (or more), the localisation of the ion-ion resonance (and the associated cut-off), which<br />

turns out to be very close to the ion cyclotron resonance of the minority species, etc.<br />

2) A code that solves the warm plasma em dispersion relation in the complex space of the wavenumber<br />

in order to clarify the effect of wave damping on the minority species, the effects of the<br />

plasma parameters (minority concentration, ion and electron temperature, parallel wave-number)<br />

on the transition to the mode conversion regime. The use of this code should also provide the<br />

power deposition profiles and the power damping rate for the entire launched spectrum.<br />

3) A 1D ray-tracing code in cylindrical geometry to take into account, at the lowest order, the<br />

geometry of the tokamak plasma. The code uses the warm plasma em dispersion relation of<br />

point 2).<br />

4) When needed, a complex 2D ray-tracing code in tokamak geometry to take into account the<br />

realistic geometry of the tokamak. This code is based on a complex full em dispersion relation<br />

and complex integration of the trajectories.<br />

5) A 1D full wave code (FELICE), which gives the linear distribution of the wave power on ion and<br />

electron species. It accounts correctly for the electron Landau damping (ELD) in the fast wave<br />

branch and in the ion Bernstein wave (IBW) branch; it also accounts for the realistic antennaplasma<br />

coupling and calculates the whole effect of the power spectrum on the various species.<br />

6) A 2D full wave code (TORIC) [A1.66], which has the same characteristics as the 1D FELICE<br />

code, but includes the real geometry of the plasma (in the flux surface coordinate system).<br />

7) A 2D full wave code (steady-state quasi-linear Fokker-Planck [SSQLFP] code), which does the<br />

same as before but includes the evolution of the 2D distribution function for the ions and<br />

electrons.<br />

Simulation of burning plasma dynamics by ICRH accelerated minority ions<br />

The main difference between present experiments and ITER will be the presence, as the main<br />

heating source, of alpha-particles produced in DT reactions. Alpha particles will mainly heat<br />

electrons, contrary to present experiments dominated by low-energy neutral beam injection that<br />

mainly heats the ions. Moreover, alpha-particles can drive stronger collective modes.<br />

As proposed in [A1.67], alpha-particle dynamics can be simulated in pure deuterium plasmas by<br />

ions accelerated by rf waves. The use of ICRH in the minority scheme (H or 3 He) can indeed<br />

produce fast particles (although with a different distribution function to that of fusion-generated<br />

alpha-particles) which, with an appropriate choice of the minority concentration, rf power and<br />

plasma density and temperature, can reproduce the dimensionless parameters ρ * fast and β fast<br />

characterising the alpha-particles in ITER. Here, ρ * fast is the normalised fast-particle radius and β fast<br />

the fast-particle beta. Thus, a device operating with deuterium plasmas in a dimensionless<br />

parameter range as close as possible to that of ITER and equipped with ICRH as the main heating<br />

scheme would allow investigation of some of the most important features of alpha-particle heated<br />

plasmas and, therefore, it would be possible to assess these issues in relevant scenarios before their<br />

implementation on ITER itself.<br />

As an example, the following reference antenna and plasma parameters were considered: 24 MW<br />

of ICRH power coupled to the plasma at a frequency f=81 MHz; toroidal magnetic field B T =8T;<br />

volume average density =4×10 20 m -3 with generalised parabolic profile (1-(r 2 /a 2 )) α and 3 He<br />

Progress Report 2006<br />

20


Fig. A1.13 – Power deposition profiles vs plasma radius for<br />

the various species<br />

minority-heating scheme. Two scenarios were taken into account:<br />

one characterised by the enhancement factor H=1.3, consistent with<br />

an ITB and peaked profiles (α n =1 α T =1), which corresponds to<br />

having β N =1.8% and on-axis values of density, temperature and beta<br />

given by, respectively, n e0 =6×10 20 m -3 , T e0 =T i0 =12 keV; the other<br />

characterised by an enhancement factor H=1, in H-mode, and flat<br />

profiles α n =0 α T =1, with β N =1.4%, and n e0 =4×10 20 m -3 ,<br />

T e0 =T i0 =10 keV. A parametric study of ICRH absorption was<br />

performed, varying the resonant layer, coupled wave spectrum,<br />

minority concentration, density and temperature, with the aim of<br />

increasing the power coupled to the minority ions and obtaining the<br />

maximum effective temperature of the tail. As an example, the results<br />

obtained in the “enhanced H-mode scenario” are reported here. In<br />

figure A1.13, the power density coupled to the various species in<br />

(W/cm 3 ) is plotted vs the plasma radius, when an optimum 3 He<br />

minority concentration of 2% (which maximises the power absorbed<br />

by the minority) is considered. From the figure it is possible to get the<br />

localisation of the deposition, r/a=0.1 the width of the deposition<br />

layer, Δr/a=0.2 for the minority and broader for the electrons, and the<br />

peak of the power density (45 Watt/cm 3 ).<br />

The quasi-linear analysis, based on the linear results shown above,<br />

allows calculation of the effective temperature of the minority ions as<br />

well as the fraction of the minority at those energies. The effective<br />

temperature was calculated to be ≈150 keV (on the peak of the<br />

absorption layer), with a fast ion fraction of about 30% leading to a<br />

fast ion β fast of about 0.8%. Figure A1.14 shows the effective<br />

temperature of the ion minority in parallel and perpendicular<br />

directions as a function of the plasma radius.<br />

Particle simulation of bursting Alfvén<br />

modes in JT–60U<br />

A numerical investigation, based on particle-in-cell<br />

simulations, of the bursting-mode phenomenology<br />

observed in negative neutral beam (NNB)-heated<br />

JT–60U discharges was performed [A1.68– A1.70]. It<br />

was shown that the experimental observations can be<br />

interpreted as the effect of nonlinear interaction<br />

between Alfvén modes and the energetic ions<br />

produced by NNB injection. In particular, the<br />

b 3<br />

keV<br />

60<br />

40<br />

20<br />

0<br />

150<br />

100<br />

50<br />

0<br />

Total ICRH power density<br />

Power to ion<br />

Power to electrons<br />

0 0.2 0.4 0.6 0.8 1<br />

r/a<br />

T eff, par<br />

T eff, perp<br />

0 0.2 0.4 0.6 0.8 1<br />

r/a<br />

Fig. A1.14 – Effective temperature of the<br />

minority vs plasma radius<br />

n H /n H0<br />

1.0<br />

0.8<br />

0.6<br />

0.4<br />

0.2<br />

Relaxed<br />

Initial<br />

After ALE<br />

0.0<br />

0.0 0.2 0.4 0.6 0.8 1.0<br />

r/a<br />

Fig. A1.15 – Nonlinear modifications of the energetic ion density<br />

profile produced by EPM saturation. Blue curve: initial (simulation<br />

and experimental) profile. Red curve: relaxed profile obtained in the<br />

simulation. Black curve: experimentally inferred profile just after the<br />

ALE occurrence, plotted here for comparison<br />

[A1.65] A. Cardinali et al., Proc. 33 rd EPS Conference on Plasma Physics (Rome 2006), on line at:http://epsppd.epfl.ch/Roma/pdf/P1_065.pdf<br />

[A1.66] M. Brambilla, Plasma Phys. Control. Fusion 41, 1 (1999)<br />

[A1.67] F. Romanelli et al., Fusion Sci. Technol. 45, 483 (2004)<br />

[A1.68] G. Vlad et al., Proc. of the Joint Varenna-Lausanne International Workshop on Theory of Fusion Plasmas, ed. by J. Connor, O. Sauter,<br />

E. Sindoni (American Institute of Physics, Varenna), Vol. 871, 250-263 (2006)<br />

[A1.69] G. Vlad et al., Proc. 21 st IAEA Fusion Energy Conference (Chengdu 2006), on line at: http://wwwnaweb.iaea.org/napc/physics/FEC/FEC2006/papers/TH_P6-4.pdf<br />

[A1.70] S. Briguglio et al., Particle simulation of bursting Alfvén modes in JT-60U, accepted for publication in Phys. Plasmas<br />

References<br />

21<br />

Progress Report 2006


A1 Magnetic Confinement<br />

3<br />

a)<br />

3<br />

b)<br />

3<br />

c)<br />

2<br />

2<br />

2<br />

A Fusion Programme<br />

α<br />

1<br />

0<br />

0 0.25 0.5 0.75 1<br />

Ê<br />

α<br />

1<br />

0<br />

0 0.25 0.5 0.75 1<br />

Ê<br />

0<br />

0 0.25 0.5 0.75 1<br />

Ê<br />

Fig. A1.16 – a) Variation in the energetic-ion distribution function in the (Ê,α) plane (Ê being the energy, α the pitchangle<br />

of the energetic ions), after saturation of the EPM, averaged on the outer plasma region, where the TAE-like<br />

mode grows. b) Volume average of the power transfer from particles to the wave (i.e., the resonance pattern), in the<br />

same region, during the linear simulation stage. c) Power transfer after EPM saturation. Red corresponds to positive<br />

values; violet to negative. The EPM saturation causes an increase in the energetic-ion distribution function at low<br />

energy and large pitch-angle. It can be shown that the increase is due to an outward radial displacement from the<br />

central (EPM) region. The displaced ions resonate with the outer mode, modifying the outer resonance<br />

^ ^<br />

F-F SD<br />

0.004<br />

0.003<br />

0.002<br />

0.001<br />

0<br />

-0.001<br />

-0.002<br />

-0.003<br />

-0.004<br />

3<br />

2.5<br />

2<br />

1.5<br />

α<br />

1<br />

0.8<br />

0.6<br />

0.4<br />

0.2<br />

E^<br />

0.5 0<br />

Fig. A1.17 – Distortion with respect to the slowing<br />

down distribution function (F^-F^SD) of the energetic-ion<br />

distribution function in the (Ê,α) plane produced by<br />

EPM saturation<br />

1<br />

investigation, related to modes with toroidal<br />

number n=1, showed that an energetic particle<br />

mode (EPM) localised around the maximum of<br />

the energetic-ion pressure gradient is driven<br />

unstable by resonant interaction with such ions.<br />

Its saturation produces radial displacement of<br />

energetic ions, in fair agreement with the<br />

experimental findings related to the so-called<br />

abrupt-large-amplitude events (ALEs)<br />

(fig. A1.15).<br />

Simulation results demonstrate that displaced<br />

ions resonate with Alfvén modes in the outer<br />

region (fig. A1.16), causing a TAE-like mode to<br />

become dominant as the saturation of the EPM<br />

proceeds. It has also been observed that the<br />

scattering due to the EPM is more effective on<br />

resonant ions than non-resonant. Besides the<br />

relaxation of the density profile, a distortion in<br />

the velocity-space distribution function is then<br />

produced (fig. A1.17). This fact can explain why<br />

a quieter phase, characterised by weaker bursting modes (the fast frequency sweeping), is<br />

observed after an ALE, allowing the system to restore the free energy needed for a new ALE. In the<br />

absence of velocity-space distortion, any reconstruction of the density profile would indeed generate<br />

relatively large amplitude modes: energetic ions would be further scattered by these modes and<br />

their density profile would be essentially clamped to the relaxed profile produced by the ALE.<br />

Once the phase-space distortion is fully taken into account, the free-energy reconstruction rate is<br />

instead set by the need to rebuild both the density profile and the resonant part of the distribution<br />

function. The slow time scale evolution of energetic ion equilibria in intermediate configurations<br />

between two successive ALEs is then characterised by a lower drive than that corresponding to the<br />

unperturbed velocity-space distribution function, and the weak modes excited are less effective in<br />

contrasting the density profile reconstruction. Only when the combined restoration of the<br />

configuration and velocity space distributions provides enough drive for a fast growing Alfvén mode,<br />

does a new ALE occur.<br />

α<br />

1<br />

Progress Report 2006<br />

22


Theory of Alfvén waves and energetic particle physics in burning plasmas<br />

An overview of the work presented here has been given in [A1.71]. A unique characteristic of burning<br />

plasmas is that the energy density of fast ions (MeV energies) and charged fusion products is a significant<br />

fraction of the total plasma energy density. Consequently, one can address two major issues of practical<br />

concern in such plasmas: i) whether fast ions and charged fusion products are sufficiently well confined to<br />

transfer their energy and/or momentum to the thermal plasma without appreciable degradation due to<br />

collective modes; and ii) whether, on longer time scales, mutual interactions between collective modes and<br />

energetic ion dynamics on the one hand and drift wave turbulence and turbulent transport on the other<br />

may decrease the overall thermonuclear efficiency of the considered system.<br />

The first issue was addressed by analysing theoretically the dynamics of shear Alfvén waves collectively<br />

excited by energetic particles in tokamak plasmas. Both linear physics, such as spectral and stability<br />

properties, as well as key nonlinear wave and particle dynamics have been identified and considered. The<br />

investigations of such processes via computer simulations have also been discussed along with the<br />

importance of benchmarking with existing or future experimental observations.<br />

In terms of consequences, the two issues have different practical implications: the first has a direct impact<br />

on the operation scenarios and boundaries, since energy and momentum fluxes due to collective losses<br />

may lead to significant wall loading and damage to plasma-facing materials; the second poses soft limits<br />

in the operation space.<br />

In the framework of plasma theory, the first issue is connected with identification of burning plasma stability<br />

boundaries with respect to collective mode excitations by fast ions and charged fusion products as well<br />

as with nonlinear dynamics above the stability thresholds; the second is associated with long time-scale<br />

nonlinear behaviour typical of self-organised complex systems.<br />

Nonlinear equilibria, stability and generation of zonal structures in toroidal plasmas<br />

The crucial role played by zonal flows [A1.72] in regulating the saturation level of drift wave turbulence and<br />

ultimately of turbulent transport [A1.73] has led to significant attention being paid to determining the<br />

quantity of zonal flows (ZFs) that can be spontaneously generated by the turbulence itself before the flows<br />

become unstable, also due to Kelvin Helmholtz (KH)–like mode excitations [A1.74-A1.76]. In this<br />

framework, drift waves (DWs) are the “primary” instability and spontaneously generate ZFs, the<br />

“secondary” instability, which can be limited in amplitude by the onset of “tertiary” KH–like modes [A1.74-<br />

A1.76]. The “tertiary” instability has been proposed to explain the nonlinear up-shift of the critical ion<br />

temperature gradient (ITG) driven turbulence threshold [A1.77].<br />

It has been proposed that long-lived saturated ZF structures, spontaneously generated by DW turbulence,<br />

can be considered as generators of neighbouring nonlinear equilibria [A1.78]. In the present theoretical<br />

framework, the general form of these neighbouring nonlinear equilibria has been computed in terms of<br />

[A1.71] L. Chen and F. Zonca, Proc. 21 st IAEA Fusion Energy Conference (Chengdu 2006), on line at: http://wwwnaweb.iaea.org/napc/physics/FEC/FEC2006/papers/OV_5-3.pdf,<br />

and submitted to Nuclear Fusion<br />

[A1.72] A. Hasegawa et al., Phys. Fluids 22, 2122 (1979)<br />

[A1.73] Z. Lin et al., Science 281, 1835 (1998)<br />

[A1.74] B.N. Rogers et al., Phys. Rev. Lett. 85, 5336 (2000)<br />

[A1.75] F.L. Hinton and M.N. Rosenbluth, Bull. Am. Phys. Soc. 45,7, 195 (2000)<br />

[A1.76] E.-J. Kim and P.H. Diamond, Phys. Plasmas 9, 4530 (2002)<br />

[A1.77] A.M. Dimits et al., Phys. Plasmas 7, 969 (2000)<br />

[A1.78] L. Chen and F. Zonca, Proc. 21 st IAEA Fusion Energy Conference (Chengdu 2006), on line at: http://wwwnaweb.iaea.org/napc/physics/FEC/FEC2006/papers/TH_P2-1.pdf,<br />

and submitted to Nucl. Fusion<br />

References<br />

23<br />

Progress Report 2006


A1 Magnetic Confinement<br />

A Fusion Programme<br />

zonal structures as well as of the characteristics of the primary DW turbulence. The derived nonlinear<br />

evolution equation for the zonal response consistently describes the temporal evolution of the zonal<br />

structures, whose time-asymptotic behaviour corresponds to nonlinear equilibria. The stability of the<br />

nonlinear equilibria determines the nature of the “tertiary” instability regime, the nonlinear up-shift of<br />

critical thresholds, and the collisionless dissipation of the zonal structures. On a shorter time-scale,<br />

the temporal evolution of the zonal response describes the DW-ZF generation and the regulation of<br />

the DW intensity by the ZFs.<br />

While the stability properties of the nonlinear zonal equilibria have been given in terms of integral<br />

eigenmode equations [A1.75], simple estimates for the threshold condition for tertiary instability can<br />

be derived in the local limit. It has also been discussed how this instability condition can be<br />

translated into an estimate of the nonlinear up-shift of the critical threshold for the ITG turbulence<br />

driven transport, known as the “Dimits-shift” [A1.77]. In fact, employing the time asymptotic<br />

response of the zonal structures as the nonlinear equilibria allows one to directly connect the starting<br />

reference equilibrium quantities to the nonlinear equilibrium features due to finite ZF amplitude as,<br />

e.g., radial modulations in the temperature profile [A1.79]. It has been shown that tertiary instability<br />

consists of trapped ion ITG modes (TITG), generated by these radial modulations of the ion<br />

temperature profile. Employing the quasi-linear description, it is has been further demonstrated that<br />

tertiary TITG turbulence [A1.78] can lead to collisionless dissipations of the zonal structures, i.e.,<br />

their quasi-linear relaxations. In this respect, the existence of TITG turbulence can then lead to the<br />

resurgence of the primary DW turbulence and of turbulent transport, which is strongly suppressed<br />

by ZFs for reference plasma equilibrium gradients below the Dimits-shift.<br />

A1.5 JET Collaboration<br />

The JET machine operated during 2006 after the long shut-down for the new diagnostic systems,<br />

new divertor, and NBI upgrading. The new ICRH antenna was not ready for integration in the<br />

machine. Three campaigns (C15-C16-C17) were carried out. The organisation of the experimental<br />

programme was led by two main task forces (S1 and S2). The experiments proposed by the other<br />

task forces (Diagnostics, Heating, Magnetics, Exhaust, DT) were incorporated in the S1 and S2<br />

experimental programme.<br />

With regard to the European Fusion Development Agreement (EFDA) JET 2006 work programme,<br />

<strong>ENEA</strong> participated in the commissioning of systems included in the JET Enhancement Programme<br />

(EP), the organisation of new enhancements for JET-EP2 (2006-2008) and the realisation of<br />

experiments in campaigns C15-C17. <strong>ENEA</strong> has provided EFDA JET with the EFDA associated<br />

leader for JET, two task force leaders (Transport and Diagnostics), one deputy task force leader<br />

(Advanced Tokamak Scenario, S2), one responsible officer (RO) in the EFDA JET close support unit<br />

(CSU) (RO for H-mode Scenario (S1) and Transport task forces) and one RO for enhancements in<br />

the EFDA JET CSU.<br />

Participation in the JET EP/EP2<br />

JET neutron profile monitor: fast data acquisition system for neutron/gamma<br />

discrimination. Digital techniques for neutron detection/spectrometry are important in view of ITER<br />

application as they allow the realisation of systems that provide high count rates (MHz),<br />

simultaneous counting and spectroscopic measurements of both neutrons and gamma-ray<br />

emission (at present not technically feasible with conventional analog pulse shape discrimination)<br />

and the possibility of post-experiment (re)processing of data with different analysis techniques and<br />

analysis of pile-up events.<br />

Under an EFDA task the 14-bit 200 MS/s digitizer system for fast sampling of pulses and<br />

Progress Report 2006<br />

24


neutron/gamma digital pulse shape discrimination (DPSD)<br />

[A1.80] to be used with scintillators was installed on the<br />

central channel of the KN3 neutron camera at JET and<br />

commissioning took place in November 2006. Data from<br />

a large number of plasma discharges were acquired. The<br />

results demonstrate the capability of the DPSD system to<br />

provide simultaneously 2.5- and 14-MeV neutron count<br />

rates as well as pulse height spectra: note the detection of<br />

ion tails in a discharge with NBI and ICRH (fig. A1.18).<br />

Comparison of analog and digital count rates indicates<br />

good agreement between the two systems (fig. A1.19).<br />

Optimisation of the system hardware and software is also<br />

in progress under an EFDA Underlying Technology task. In<br />

particular, pile-up is currently being investigated with the<br />

use of a set of data acquired with the DPSD system on<br />

JET. The plan is to prepare a software module to deal with<br />

pile-ups, and also to perform neutron/gamma separation<br />

and pulse height analysis on such events, which will<br />

eventually be included in the existing software package.<br />

Along the same line of research, two further tasks have<br />

been started in collaboration with TRINITI on neutron<br />

detector digital electronics and radiation hardness testing.<br />

3×10 4<br />

CVD diamond detectors for neutron measurement.<br />

Shot #68569<br />

Under the Small Enhancement agreement, two diamond<br />

detectors produced by the chemical vapour deposition<br />

1×10 4<br />

(CVD) technique were installed at JET and worked<br />

continuously during the C15-C17 experimental<br />

50 54 58 62<br />

campaigns. One detector is polycrystalline diamond<br />

Time (s)<br />

(p–CVD) covered with a thin layer (2 μm) of lithium fluoride<br />

Fig. A1.19 – Comparison between analog and digital count<br />

(LiF) 95% enriched in Li-6. The latter converts low-energy<br />

rates in the 2.5-MeV neutron energy range (JET discharge<br />

neutrons into alphas and tritons of about 2 MeV and<br />

#68569)<br />

2.7 MeV respectively, which are easily detected by the<br />

diamond film and hence the total neutron emission can be<br />

measured. To further enhance its response the detector is embedded in polyethylene. The other detector<br />

is a single crystal diamond (SCD) film with a special heavily doped boron contact covered with a layer of<br />

enriched 6 LiF (2 μm thick) for simultaneous detection of total neutron emission and 14-MeV neutron<br />

emission from triton burn-up. This detector was also used in a first attempt to perform neutron<br />

spectrometry. Both detectors also measured the time-dependent neutron emission during each pulse.<br />

The goal was a) to demonstrate the capability and reliability of diamond detectors as neutron monitors<br />

during long–lasting experiments under ITER-like working conditions; b) to demonstrate the capability of a<br />

single SCD detector covered with LiF to simultaneously detect and discriminate between total and 14-MeV<br />

neutrons produced by triton burn-up. The job output will be a comparison between CVD data and those<br />

obtained from the official JET neutron detectors (fission chambers and silicon diodes).<br />

Figure A1.20 shows the correlation between the total neutron emission measured by the p-CVD (as well<br />

as the SCD) and that (average value) recorded by the fission chambers (FCs) available at JET. The degree<br />

Counts (arb. units)<br />

10 -2<br />

10 -4<br />

Shot #68445<br />

t = 46.0 s<br />

t = 47.4 s<br />

t = 48.8 s<br />

t = 50.2 s<br />

t = 51.6 s<br />

10 -6 0 4 8 12 16<br />

Proton energy (MeV)<br />

Fig. A1.18 – Pulse height spectra in JET discharge<br />

#68445: NBI and ICRH are injected at t>46 s<br />

Counts/s<br />

7×10 4<br />

5×10 4<br />

neutron analog (10 ms)<br />

gamma analog (10 ms)<br />

neutron digital (10 ms)<br />

gamma digital (10 ms)<br />

[A1.79] S.E. Parker et al., Phys. Plasmas 6, 1709 (1999)<br />

[A1.80] M. Riva, B. Esposito and D. Marocco, Proc. 10 th Inter. Conference on Accelerator & Large Expt. Physics Control Systems - ICALEPCS<br />

(Geneva 2005), paper P-O2.041-4, http://epaper.kek.jp/ica05/proceedings/pdf/P3_041.pdf<br />

References<br />

25<br />

Progress Report 2006


A1 Magnetic Confinement<br />

A Fusion Programme<br />

Diamonds (counts)<br />

8×10 4<br />

6×10 4<br />

4×10 4<br />

2×10 4 0<br />

CVD02<br />

SCD03<br />

5×10 15<br />

y=2.042×10 -12 x +9.463×10 2<br />

R 2 =9.978×10 -1<br />

of agreement between the two detectors is excellent in the whole range of interest for JET, that is<br />

from 5.0×10 14 n/shot up to the highest neutron yields (>4×10 16 n/shot) produced during C17.<br />

Figure A1.21 reports the behaviour of the p-SCD detector vs JET pulses and thus as a function of<br />

time. Also in this case the stability is proven.<br />

<strong>ENEA</strong>’s participation in the JET-EP2 concerns further implementation of the enhancements: fast<br />

data acquisition for the neutron camera; new calibration, with new fast electronics for the NE213<br />

compact neutron spectrometer; a new monochrystal CVD to be tested for the neutron<br />

spectrometry; new CVD detectors to be tested for ultraviolet radiation detection.<br />

Participation in experimental campaigns C15-C17<br />

<strong>ENEA</strong> has presented JET with about 20% of the proposals considered for campaigns C15-C17. The<br />

proposals are mainly dedicated to the work carried out by TFS2 (Advanced Tokamak Scenario), TFM<br />

(Magnetics), TFD (Diagnostics). The following is a short presentation of some preliminary results of<br />

the 2006 experiments.<br />

Advanced Tokamak Scenario<br />

SCD<br />

y=9.953×10 -13 x +1.043×10 2<br />

R 2 =9.978×10 -1<br />

1.5×10 16 2.5×10 16 3.5×10 16<br />

FC (counts)<br />

Fig. A1.20 – Correlation between p-CVD and SCD<br />

detectors and FC<br />

• Optimisation of hybrid advanced regime with electron heating. The activity consisted in planning<br />

and co-leading the sessions and coordinating the diagnostics in the control room. The hybrid<br />

regime with T e >T i was established, and subsequently i) density scan, ii) current profile scan, iii)<br />

power scan were carried out. This experiment was done to complete the database with more<br />

refined diagnostic coverage, in particular, the charge exchange and motional Stark effect (MSE).<br />

Ion temperature, rotation profiles and impurity density were carefully measured for transport<br />

analysis. The plasma parameters of the reference pulse (#62779, in C13) were magnetic field<br />

B T =3.2 T, plasma current I p =2.3 MA, neutral beam heating power P NBI =9 MW, ion cyclotron rf<br />

power P ICRH =9 MW, lower hybrid current drive power P LHCD =1 MW. The hybrid current profile<br />

was obtained with LHCD in preheating. The main heating was performed with equal neutral beam<br />

and ICRH power, resulting in peak temperatures T e =9-11 keV, and T i =7-8 keV at a density of<br />

3×10 19 m -3 . The confinement regime was H-mode with H89 ~2, and small edge localised modes<br />

(ELMs). The scenario is characterised by a sawtooth-free period and by frequent and very small<br />

ELMs, after LH preheating (fig. A1.22), where the H89 ~2, and small n=2 NTMs (neoclassical<br />

tearing modes) are detected. The spatial q profile is typical of hybrid regimes (fig. A1.23) where a<br />

large region of flat shear (with q min ≥1) is created at the plasma centre, when the maximum β N is<br />

reached.<br />

• ITER-relevant ITB scenario at high β N and bootstrap fraction. The ITER non-inductive scenario<br />

has to reach a high H-factor (H98(y,2)~1.5) and normalised beta (β N ≥3), in the presence of a<br />

fraction of bootstrap current J bs , close to 50% of the total current. The scenario is characterised<br />

by a non-monotonic q profile and the formation of an ITB located close to the point of minimum<br />

value of safety factor q min . Experiments were done on JET at plasma parameters: magnetic field<br />

Ratio<br />

1.5<br />

1.3<br />

1.1<br />

0.9<br />

0.7<br />

y= -2.869×10 -6 × +1.252<br />

R 2 =2.780×10 -4<br />

0.5<br />

68500 68700 68900 69100<br />

Pulses<br />

Fig. A1.21 – Ratio between p-CVD and FC counts vs<br />

JET pulses<br />

Progress Report 2006<br />

26


Fig. A1.22 – From the top. Shot #68383 First plot: heating<br />

waveforms LHCD total power (red), ICRH (magenta), neutral<br />

beams (blue). Second plot: β N (red) and H89 factor (blue); Third<br />

plot: n=1 (red), n=2 (blue) MHD modes. Fourth plot:<br />

measurements of T e in two positions. Fifth plot: D α outer divertor<br />

B T =2.3 T, plasma current I p =1.5 MA, neutral beam<br />

heating power P NBI =22 MW, ion cyclotron heating<br />

power P ICRH =6.2 MW, LHCD power<br />

P LHCD =2.2 MW, density close to the Greenwald<br />

limit n G =I p /(π a 2 )=0.5×10 20 m -3 , T e =3-5 keV. The<br />

safety factor at the edge was q 95 ~5, and the<br />

triangularity δ~0.4. A q profile with negative<br />

magnetic shear is formed using LHCD early in the<br />

discharge, and high NBI and ICRH power are<br />

added when the minimum q is just above 2, to<br />

trigger an ITB as q min crosses 2. Two configurations<br />

were used for this experiment: ITER_AT (Advanced<br />

Tokamak) and high beta poloidal, in two separate<br />

sessions. To maintain low ELMs, neon or D 2 gas<br />

puffing is used, and this tool helps also to make the<br />

scenario suitable for operation with a Be wall.<br />

Figure A1.24 shows the main results in terms of<br />

normalised beta: the normalised beta is plotted vs<br />

the no-wall beta limit (defined as β N no-wall =4l i ). The<br />

best results β N,max ~3 are obtained when both<br />

electron and ion ITBs occur at the same radius and<br />

strength. The value of the fusion gain vs the density<br />

normalised to the Greenwald density is consistent<br />

with that useful for ITER (fig. A1.25). This scenario<br />

so far is limited by strong ELMs appearing at peak<br />

β N (fig. A1.26). Despite the large ELMs, the ITB<br />

persists for several confinement times, but then it is<br />

lost due to detrimental MHD activity linked to the<br />

presence of low magnetic shear, as the q profile<br />

evolves from negative to positive magnetic shear.<br />

V 10 3 eV V<br />

10 7 W<br />

0.8<br />

0.4<br />

0<br />

1.5<br />

0.5<br />

0.20<br />

0.10<br />

0<br />

8<br />

6<br />

4<br />

2<br />

0.4<br />

0.2<br />

q<br />

0<br />

5<br />

4<br />

3<br />

2<br />

1<br />

46 48 50 52 54 56<br />

Time (s)<br />

Time = 49.94 s<br />

Time = 51.95 s<br />

Time = 53.96 s<br />

#68383<br />

2.0 2.5 3.0 3.5<br />

R(m)<br />

Fig. A1.23 – Evolution of the q(r) profile as measured by MSE<br />

β N<br />

4.0<br />

3.5<br />

3.0<br />

2.5<br />

2.0<br />

1.5<br />

1.0<br />

0.5<br />

0<br />

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0<br />

4I i<br />

Fig. A1.24 – Normalised beta β N vs the no-wall<br />

beta limit defined as β N no-wall =4l i<br />

H 89 β N /q 95<br />

2<br />

0.35<br />

0.30<br />

0.25<br />

0.20<br />

0.15<br />

0.10<br />

0.05<br />

0<br />

0 0.2 0.4 0.6 0.8 1<br />

n e /n G<br />

Fig. A1.25 – Figure of merit of fusion gain<br />

H 89 β N /q 2 95 vs normalised electron density<br />

27<br />

Progress Report 2006


A1 Magnetic Confinement<br />

A Fusion Programme<br />

Fig. A1.26 – Time evolution of β N , Z max<br />

plasma position, elongation κ, H α and<br />

MHD (n=1) monitors<br />

Diagnostics<br />

• High-resolution Thomson<br />

scattering (KE11). <strong>ENEA</strong><br />

Frascati has been involved in<br />

the commissioning of the highresolution<br />

Thomson scattering<br />

(HRTS) system required for the<br />

exploitation of many<br />

experiments. The analysis<br />

code of the HRTS data was<br />

developed and used during<br />

β N<br />

Zmax (m)<br />

κ<br />

H α<br />

MHD n=1<br />

3.0<br />

2.8<br />

2.6<br />

2.4<br />

1.85<br />

1.75<br />

1.76<br />

1.72<br />

1.68<br />

2.0<br />

1.5<br />

1.0<br />

0.5<br />

commissioning on the plasma. A preliminary project<br />

of a system for laser alignment control using<br />

cameras has been outlined. The aim is to monitor<br />

the laser beam incident on the input window and on<br />

the beam dump internal to the vacuum vessel.<br />

2<br />

1<br />

0<br />

#68927<br />

44.5 45.0 45.5 46.0 46.5<br />

Time (s)<br />

#70068<br />

Time = 47 s<br />

• Motional Stark effect. The tools presently available<br />

to determine the spatial q profile were studied: i)<br />

EFIT + MSE ; ii) EFIT+polarimetry; iii) point-to-point 4<br />

analysis. The aim of the study was to determine the<br />

Time = 46 s<br />

sensitivity of the q profile to the data sources and to<br />

2<br />

the method, and the accuracy of the subsequent<br />

determination, in particular for hybrid discharges<br />

2.0 2.5 3.0 3.5<br />

(exp S2-4.3 - Optimisation of a hybrid scenario with<br />

R(m)<br />

electron heating) where the q(r) spatial profile in the<br />

Fig. A1.27 – Spatial profiles of the q safety factor<br />

plasma central region is critical. For these<br />

discharges substantial agreement has been<br />

detected between the results of the various methods. The MSE data analysis was critically<br />

reviewed by comparing different constraints on the EFIT data, e.g., choice of MSE channel<br />

weights, data from polarimetry, variation in pressure constraints and polynomial degree. Where<br />

possible, the results were checked against proof of the existence of rational surfaces for q given<br />

by mode analysis of fast diagnostics or the occurrence of sawteeth. As an example, figure A1.27<br />

shows the q profiles in the proximity of a 3/2 mode reconnection, with the final value of q in the<br />

region interested by the mode close to 1.5. An alternative method for processing MSE data,<br />

previously developed at JET [A1.81], has been retrieved and tested on several discharges against<br />

the EFIT equilibrium. According to some hypotheses on the shape of internal flux surfaces, once<br />

the last closed surface is known, it is possible to process individual MSE data points, obtaining<br />

independent determinations of the radial q points. This minimises the effect on the overall profile<br />

of the errors on individual channels (some of which are occasionally affected by spurious radiation<br />

which makes them completely unreliable). More work is being done to extend the comparison to<br />

several different experimental scenarios. The activity in support of S2 experiments was<br />

concentrated on hybrid heating studies and on high β N . Inter-shot analysis of the q profiles has<br />

been a useful tool to achieve the desired configuration, mainly monitoring the central q value.<br />

Broadening of the q profile observed by MSE data in particular conditions of high beta discharges<br />

is under detailed investigation.<br />

• Polarimetry. Polarimeter data were analysed to find the consistency of measurements with various<br />

theoretical models developed recently. A dataset including 300 discharges (2003-2006) was<br />

created, where the validation of data of the interferometer and the light detection and ranging -<br />

Thomson scattering (LIDAR-TS) system was accurately checked. The dataset contained<br />

measurements of channel 3 of the JET polarimeter [A1.82]. A parasitic experiment (Polarimetry at<br />

q<br />

10<br />

8<br />

6<br />

Progress Report 2006<br />

28


0.08<br />

Fig. A1.28 – Line integrated plasma density (n _ e ) deduced from Cotton-Mouton is<br />

plotted vs neL measured by the interferometer<br />

n e,Cotton-Mouton<br />

0.06<br />

0.04<br />

0.02<br />

0<br />

-0.01<br />

0 10 20 30<br />

n e,interf.<br />

s3/s2<br />

0.22<br />

0.18<br />

0.14<br />

0.10<br />

KG4 data PHAS<br />

shot#66002 ch#3<br />

numerical solution<br />

numerical solution<br />

including T e<br />

corrections<br />

0.06<br />

0.02<br />

high n e and T e ) was partially executed (during the<br />

40 45 50 55 60 65 70<br />

TOFOR commissioning sessions, 19-21 April 2006) to<br />

Time (s)<br />

detect the effect of the (high, >6 keV) electron Fig. A1.29 – Cotton-Mouton phase shift measured by<br />

temperature on model predictions (shots #66016, channel 3 of the polarimeter (blue trace) shot #66002,<br />

#66068). The main conclusions of the analysis are that together with the calculation of the signal made using the<br />

the Cotton-Mouton phase shift can be used for Stokes equations (black stars) and including the effect of<br />

evaluation of the line integral of electron density. the electron temperature (red crosses)<br />

Figure A1.28 shows the line integral of electron density<br />

n _ e obtained from the polarimeter Cotton-Mouton measurement vs the n_ e measured by the<br />

interferometer. Substantial agreement emerges from the two independent measurements of plasma<br />

density. The model of Stokes equations (where the inputs are taken from LIDAR TS and EFIT equilibrium)<br />

is in good agreement with measurements even when corrections for the electron temperature are<br />

included in the analysis (fig. A1.29).<br />

• Neutron emission profiles and fuel ratio measurements. ELMy-H mode plasma scenarios with tritium<br />

puff of the Trace Tritium Experiment have been analysed by using simultaneous DD 2.5–MeV and DT<br />

14-MeV neutron emission profile measurements. Two-dimension spatial profiles of the tritium<br />

concentration were obtained, which provided useful information for transport analysis and tritium<br />

diffusion [A1.80].<br />

• NE213 liquid scintillator. A new neutron detection system has been built and installed at JET. It is based<br />

on a liquid scintillator cell (NE213-BC501 A), a light emitting diode (LED) connected to stabilisation<br />

hardware for PMT high voltage gain control, and a light guide as interface/coupler with the<br />

photomultiplier XP2020. The LED system provides calibrated and stable light pulses (at 1 kHz) used as<br />

reference for gain control purposes. The new system makes use of DPSD electronic hardware that<br />

provides separate neutron and gamma signals for spectra acquisition. Pulse height spectra of various<br />

plasma scenarios were acquired during the JET restart and 2006 experimental campaigns. The present<br />

activity together with the project Prototype Digital Pulse Shape Discrimination Module, a new<br />

neutron/gamma DPSD, is aimed at improving neutron spectroscopy at high count-rate operation for<br />

future JET applications, and at assessing its potential for ITER.<br />

A1.6 PROTO–SPHERA<br />

The PROTO-SPHERA [A1.83] system proposed at the <strong>ENEA</strong> Frascati research centre is a simply<br />

connected magnetoplasma configuration composed of a spherical torus (ST, with external diameter<br />

[A1.81] R. Giannella et al., Rev. Sci. Instrum. 75, 4247 (2004)<br />

[A1.82] F. Orsitto et al., Proc. 33 rd EPS Conference on Plasma Physics (Rome 2006), on line at: http://epsppd.epfl.ch/Roma/pdf/P1_073.pdf<br />

[A1.83] F. Alladio et al, Nucl. Fusion 46, S613 (2006)<br />

References<br />

29<br />

Progress Report 2006


A1 Magnetic Confinement<br />

A Fusion Programme<br />

Anode<br />

Spherical torus<br />

Divertor PF coils<br />

Screw pinch<br />

Cathode<br />

R=R EL<br />

a)<br />

Water-cooled anode ring<br />

b)<br />

SP<br />

SP<br />

I e<br />

Gas flux<br />

ST<br />

ST<br />

I ST<br />

R EL =0.4 m<br />

Directly heated cathode ring<br />

Gas exhaust<br />

2R sph =0.7 m, with closed flux surfaces and toroidal<br />

plasma current I ST ≤240 kA) and a hydrogen plasma<br />

arc, taking the form of an electrode-fed screw pinch<br />

(SP, with length L Pinch ~2 m and midplane diameter<br />

2×ρ Pinch ~0.08 m, with open flux surfaces and plasma<br />

electrode current I e =60 kA), see figure A1.30a). Such a<br />

combined plasma configuration has been devised<br />

theoretically under the name "flux-core-spheromak"<br />

(FCS). The central metallic conductor of a spherical<br />

tokamak will be replaced in PROTO-SPHERA by the<br />

screw pinch acting as a plasma central column. The SP<br />

and the ST will have a common embedded magnetic<br />

separatrix: resistive instabilities will drive magnetic<br />

reconnections, injecting magnetic helicity, poloidal flux<br />

and plasma current from the electrode-driven SP into<br />

the ST and converting into plasma kinetic energy a<br />

fraction of the injected magnetic energy. The SP will be<br />

magnetically given a disk-shape near each electrode<br />

(fig. A1.30b)), with singular magnetic X-points on the<br />

2 m<br />

symmetry axis.<br />

Fig. A1.31 – MULTI-PINCH<br />

The MULTI-PINCH experiment (fig. A1.31) is being built<br />

as an initial partial setup of PROTO-SPHERA, devoted<br />

to assessing and clarifying the most critical points of the PROTO-SPHERA experiment from the SP<br />

point of view: to explore the breakdown conditions and the pinch stability in the starting phase of<br />

the PROTO-SPHERA discharge, in the presence of the poloidal field (PF) shaping coils alone and<br />

therefore in the absence of the spherical torus.<br />

2.5 m<br />

Fig. A1.30 – a) Sketch of the PROTO-SPHERA system; b) Cut-out sketch of plasma and electrodes<br />

As a sign of international support for this project, a collaboration in the field of spherical tokamaks<br />

has been established with the UKAEA-Culham Association. <strong>ENEA</strong> Frascati has been contributing<br />

with personnel to the MAST experiment in Culham since 2004. In 2004 UKAEA Culham donated to<br />

Frascati the available START equipment (in particular the vacuum vessel), and further contributions<br />

from UKAEA-Culham can be expected during the final construction phases, commissioning and<br />

operation of MULTI-PINCH, with respect to diagnostics and manpower.<br />

SP<br />

Progress Report 2006<br />

30


Fig. A1.32 – The four pairs of MULTI-<br />

PINCH PF coils and an enlargement<br />

of a few details<br />

Fig. A1.33 – Isometric view of the MULTI-PINCH anode<br />

Fig. A1.34 – Isometric view of the MULTI-PINCH cathode<br />

MULTI-PINCH will produce a stable screw pinch with current I e ≤8.5 kA, namely, the current expected in<br />

PROTO-SPHERA before the ST formation. The four pairs of PF shaping coils will be fully recovered for<br />

PROTO-SPHERA. In 2005 the constructive design of the PF shaping coils was completed with ASG<br />

Superconductors (Genoa, Italy) and their construction will be completed by the beginning of 2007<br />

(fig. A1.32).<br />

A European call for tender for the construction of the remaining parts of the MULTI-PINCH load assembly<br />

will be sent out in spring 2007. Examples of the detailed drawings for the MULTI-PINCH load assembly are<br />

given in figures A1.33-A1.34.<br />

The power supplies have been defined and their procurement should be such as to have the machine<br />

ready for operation in 2009.<br />

If the MULTI-PINCH experiment gives positive results, the PROTO-SPHERA setup can be completed by<br />

adding the ST compression coils, along with an improved power supply, capable of raising the pinch<br />

electrode current from I e ≤8.5 kA to I e =60 kA in ∼1 ms.<br />

31<br />

Progress Report 2006


A2 Preliminary Design of FT3<br />

A Fusion Programme<br />

Fusion is the most promising energy source as it can satisfy the energy needs in a safe and environmentally<br />

responsible way. For fusion to play a major role by the second half of the 21st century, rapid exploitation of<br />

ITER and an adequate parallel programme of material development (IFMIF) are mandatory, as proposed in<br />

the so–called “fast track” approach to fusion energy. Within this approach, the construction of a<br />

demonstration/ prototype reactor (DEMO) could start after ten years of ITER operation. Such an ambitious<br />

time schedule specifically requires rapid progress in the exploitation of ITER during the first ten years of<br />

operation, so that the DEMO regimes of operation can be demonstrated by the start of DEMO construction.<br />

This requires parallel R&D activities on devices that are able to simulate burning plasma conditions but are<br />

more flexible than a nuclear device such as ITER.<br />

The European Power Plant Conceptual Study shows that the DEMO regimes must go beyond the regimes<br />

developed for ITER. Although the extrapolation in plasma parameters (with respect to ITER) is limited, their<br />

demonstration will require a significant exploratory effort. Indeed, DEMO will operate with a fraction of selfgenerated<br />

(bootstrap) current close to 70%, use sophisticated methods for plasma control and require<br />

techniques to reduce the heat flux on the plasma–facing components. All these requirements push the<br />

plasma close to the operational limits where the risk of plasma disruptions is high. Furthermore, different<br />

technological solutions for plasma–facing components and control methods have to undergo testing, which<br />

would clearly be difficult and expensive to perform directly on a nuclear device such as ITER. Thus, the<br />

successful development of the DEMO scenarios, prior to testing them on ITER, requires a preparatory<br />

activity on smaller (than ITER) devices with sufficient flexibility and capable of simulating burning plasma<br />

conditions.<br />

Although many of the existing devices can provide important contributions to the preparation of ITER<br />

operation, the requirement that the plasma behaviour be sufficiently close to that of ITER sets stringent<br />

constraints on the plasma conditions that must be achieved in order to investigate ITER-relevant scenarios<br />

in a meaningful way. The aim of the present proposal is to show how the preparation of ITER scenarios can<br />

be effectively implemented on a new facility that will: i) work with deuterium plasmas, hence avoiding the<br />

problems associated with the use of tritium, and will simulate alpha–particle dynamics by using fast ions<br />

accelerated by heating and current drive systems; ii) work in a dimensionless parameter range close to that<br />

of ITER; iii) be capable of long pulse operation at high plasma performance; iv) test technical solutions (e.g.,<br />

the use of full tungsten) for the first wall/divertor that are directly relevant to ITER and DEMO.<br />

Such a facility (FT3) could be ready in advance of the ITER operation phase and would require, taking into<br />

account the infrastructures available in Italy, limited investment and operation costs. FT3 would be<br />

designed, constructed and operated in the framework of a collaboration with other associations. In<br />

particular, FT3 would make use of the competence available at <strong>ENEA</strong>, the National Research Council (CNR)<br />

Milan and at the Reversed Field Pinch Experiment (RFX) consortium and would be the focus of Italian<br />

activities in fusion after completion of the FTU and RFX scientific programmes.<br />

Progress Report 2006<br />

32


A2.2 Scientific Motivation of the Proposal<br />

Rationale for the choice of FT3 parameters. The conditions to be satisfied in order to reproduce<br />

ITER–relevant plasmas can be summarised as follows:<br />

• ITER–relevant geometry (same shape of magnetic surfaces and divertor configuration);<br />

• a ratio between energy confinement time and electron-ion equipartition time similar to that of ITER;<br />

• production and confinement of energetic ions in the half-MeV range;<br />

• a large ratio between heating power and device dimensions to simulate the large heat loads on the<br />

divertor plasmas;<br />

• pulse duration (normalised to the plasma current diffusion time) similar to that of ITER to study plasma<br />

scenarios in steady–state conditions.<br />

It is possible to show that these conditions imply the following set of parameters:<br />

• plasma current I above 4.6 MA;<br />

• auxiliary heating systems able to accelerate the plasma ions to energies in the range of 400 keV;<br />

• device dimension of 1.8 m;<br />

• pulse duration up to 100 s.<br />

To accelerate plasma ions up to 400 keV, it is impossible to use neutral beams produced by accelerating<br />

positive ions, which is the most diffuse heating scheme, as neutralisation efficiency rapidly drops above<br />

140 keV. Other methods such as ion acceleration by ICRH or neutral beams produced by accelerating<br />

negative ions have to be employed.<br />

The FT3 parameters are shown in table A2.I and compared with those of JET, JT60 SA (the proposed upgrade<br />

of the JT60-U device, under the Broader Approach Agreement) and ITER. Comparison of FT3 with JET and<br />

JT60-SA shows that the dominant heating scheme in FT3 is ICRH, whereas in JET and JT60-SA, positive<br />

neutral beam injector is mostly employed; thus only in FT3 can fast ions in the correct energy range be<br />

produced; also the pulse duration is much longer in FT3 than in JET.<br />

The initial configuration will be equipped with ICRH (20 MW), ECRH (4 MW) and LHCD (6 MW) power.<br />

Although such a configuration is adequate to investigate the physics issues relevant to the FT3 mission,<br />

the machine is designed so that, if necessary, further upgrades in auxiliary power (in particular a neutral<br />

beam injector) could be accomodated.<br />

Plasma parameters and equilibrium configurations. The ITER design currently foresees the<br />

investigation of three main equilibrium configurations: a) a standard H-mode at I=15 MA with a broad<br />

pressure profile (p o /=2); b) a hybrid mode at I=11 MA with a narrower pressure profile (p o /=3); c) a<br />

steady-state scenario at I=9 MA with a peaked pressure profile (p o /=4). The FT3 equilibrium<br />

configurations have been designed so as to reproduce the ITER equilibrium configurations with the plasma<br />

current being scaled by a factor of 3. The corresponding<br />

Table A2.I – FT3, JET, JT60-SA and ITER parameters<br />

plasma parameters are shown in table A2.II which reports<br />

the parameters achievable with an auxiliary power of<br />

FT3 JET JT60-SA ITER<br />

20–30 MW for each scenario.<br />

All the plasma equilibria satisfy the following constraints:<br />

a) a minimum distance of 3 λ E between plasma and first<br />

wall to avoid interaction between plasma and main<br />

chamber (here, λ E is the energy e-folding length,<br />

assumed to be 1 cm on the equatorial plane); b) current<br />

density in the poloidal field coils not exceeding 30 MA/m 2 .<br />

Within these constraints enough flexibility is maintained to<br />

allow different plasma shapes, efficient pumping and<br />

strike point sweeping. The location of the poloidal field<br />

R(m)/a(m) 1.8/0.6 3.0/1.0 3.0/1.0 6.2/2.1<br />

B(T) 6.7 3.9 2.7 5.3<br />

I(MA) 5.0 3.9 5.0 15<br />

P ICRH (MW) 20 12 0 20<br />

P NNBI (MW) 0 0 10 40<br />

P PNBI (MW) 0 25 24 0<br />

P ECRH (MW) 4 0 7 20<br />

P LH (MW) 6 3 0 20 (*)<br />

t flat-top (s) ∞ 10 ∞ ∞<br />

(*) to be decided<br />

33<br />

Progress Report 2006


A2 Preliminary Design of FT3<br />

A Fusion Programme<br />

Table A2.II – FT3 plasma parameters. The magnetic field is<br />

6.7 T in all the cases<br />

H-mode H-mode Hybrid Steady state<br />

I(MA)/q 95 5/3 5/3 3.6/4 2.8/4.9<br />

H 98 1.0 1.0 1.3 1.5<br />

n 20 3.7 2.6 1.95 1.35<br />

n/n GW 85% 60% 60% 60%<br />

P(MW)/P th (MW) 30/13-23 20/11-17 20/9-13 30/8-10<br />

β N 1.85 1.42 1.8 2.1<br />

t flat-top (s) 6 6 30 100<br />

τ E (s) 0.42 0.48 0.47 0.25<br />

T o (keV) 7.9 8.6 8 13<br />

T plate (eV) 22 26 67 76<br />

f rad 32% 27% 30% 53%<br />

coils has been optimised to minimise the magnetic energy, produce enough magnetic flux (up to<br />

25 Wb) for the formation and sustainment of each scenario and produce a fairly good field null at<br />

plasma breakdown (B p /B T


W/cm 3<br />

60<br />

40<br />

20<br />

Hf power absorption by species Minority ion distribution function<br />

0<br />

a) b)<br />

Total ICRH power density<br />

Power to ion<br />

-1<br />

Power to electrons<br />

-2<br />

Maxwellian<br />

-3<br />

0<br />

0 0.2 0.4 0.6 0.8 1<br />

r/a<br />

log(F)<br />

-4<br />

-5<br />

0 100 200 300 400<br />

E(keV)<br />

Fig. A2.2 – ICRH power deposition<br />

profile for various absorption<br />

mechanisms a) and minority-ion<br />

distribution function b). The dominant<br />

mechanism is minority absorption (red<br />

curve) which produces localised<br />

heating in the plasma centre, similar to<br />

alpha-particle heating in ITER. The fast<br />

ion energy is in the range of 400 keV<br />

an energetic ion population in the direction parallel to the equilibrium magnetic field, complementing in this<br />

way the physics that can be studied with ICRH–produced fast ions with velocity mostly perpendicular to<br />

the equilibrium magnetic field.<br />

Ion cyclotron absorption was estimated using the FELICE and TORIC codes. Both codes solve the integrodifferential<br />

equation for wave propagation and absorption: FELICE solves the equation in slab geometry<br />

wirh the use of the self-consistent electric field radiated by the antenna; TORIC solves the equation in<br />

toroidal geometry by employing a spectral method. Three absorption regimes can possibly play a role:<br />

minority absorption (which is the absorption channel to be maximised), electron Landau damping and<br />

mode conversion to the ion Bernstein wave. The analysis by the FELICE code tends to give a lower<br />

minority absorption than those from TORIC. A minority concentration of 2% yields a minority absorption of<br />

50% (FELICE) or 70% (TORIC) with a two–strap antenna with relative phase 180°, the remaining power<br />

being directly absorbed by the electrons. The power deposition profiles are shown in figure A2.2a) for the<br />

various absorption mechanisms. The parameters of the ion tails produced at a power level of 24 MW are<br />

in agreement with the Stix theory, with the local absorbed power density obtained by the deposition code.<br />

For the case shown in the figure, the effective temperature of the ion tail predicted by the Stix theory is 188<br />

keV for a power density of 45 MW/m 3 . The minority ion distribution<br />

Steady state<br />

function is shown in figure A2.2b). The fast–particle concentration is<br />

β N =2.1 T 0 =13 keV n 0 =21×10 19 m -3<br />

0.3%. Note that a slowing down distribution function with a maximum 0.12<br />

P<br />

energy of 400 keV has an average energy between 189 keV and<br />

EC = 3 MW<br />

q = 2<br />

W sat<br />

149 keV for a critical energy between E c =150 keV and E c =50 keV. 0.10<br />

Therefore, the fast–particle population is in the correct range of<br />

0.08<br />

parameters to simulate the ITER fast–particle dynamics.<br />

The MARS code was used to perform a preliminary analysis of the<br />

global MHD stability for the steady–state scenarios in order to<br />

investigate the possibility of stabilising resistive wall modes. The nowall<br />

beta limit corresponds to β Nc =2.8, whereas an ideal wall at<br />

r/a=1.3 has a beta limit corresponding to β Nc =3.24. Feedback<br />

control analysis shows that the use of internal poloidal field sensors<br />

can allow full stabilisation of the mode, using both internal and<br />

external feedback coils, whereas radial field sensors do not allow<br />

stabilisation.<br />

(green) and with (red) EC power applied<br />

The ECRH system on FT3 is mainly dedicated to stabilisation of<br />

neoclassical tearing modes in hybrid and steady–state scenarios, at densities below 3.6×10 20 m -3 , which<br />

is the cut-off for the ordinary mode for the chosen frequency of 170 GHz (the same as ITER).<br />

As an example, figure A2.3 shows the m/n=2/1 island with (W) evolution for a 2.8 MA scenario and<br />

β N =2.1. The wave is launched from an upper port at an angle of 10 ° . Wave propagation is evaluated with<br />

the electron cyclotron wave Gaussian beam (EC GB) ray-tracing code. The m/n=2/1 island evolution as<br />

determined by the modified Rutherford equation is also shown in figure A2.3. The island width (6 cm) is<br />

maintained below the ECRH deposition width for an injected power of 3 MW and corresponds to about<br />

50% of the value at saturation without ECRH applied.<br />

Lower hybrid current drive can be used on FT3 to control the current density profile in advanced scenarios.<br />

W(m)<br />

0.06<br />

Δ ' p =-2 j_peak EC /j bs ~ 1.08<br />

w/δ j = 1<br />

0.04 EC on<br />

B t =6.7 T r s /a=0.68<br />

0.02 β p =0.6(β cr =0.05) ω=1.3 kHz<br />

0<br />

0 0.5 1 0.5 2<br />

t(s)<br />

Fig. A2.3 – Evolution of the 2/1 island without<br />

35<br />

Progress Report 2006


A2 Preliminary Design of FT3<br />

1.2<br />

0.8<br />

Fig. A2.4 – Lower hybrid wave trajectories for three values of the<br />

parallel refractive index<br />

A Fusion Programme<br />

Z(m)<br />

0.4<br />

0<br />

-0.4<br />

-0.8<br />

-1.20<br />

-1.20 -0.8 -0.4 0<br />

R(m)<br />

0.4<br />

0.8<br />

1.20<br />

A2.3 Preliminary Design Description<br />

A study of LH penetration and absorption was<br />

performed in a parameter range typical of FT3 scenarios.<br />

Figure A2.4 shows the ray trajectories for a plasma<br />

equilibrium representative of FT3 scenarios with an<br />

average density 10 20 m -3 and a central temperature of<br />

13 keV. The wave frequency is 3.7 GHz and three<br />

values of the parallel refractive index are considered. In<br />

all the cases the wave is absorbed around mid–radius as<br />

requested for this kind of scenario. Current drive<br />

efficiencies in the range 0.3×10 20 Am 2 /W are predicted.<br />

Load assembly. The FT3 load assembly (fig. A2.5) consists of the vacuum vessel and its internal<br />

components (first wall, divertor, passive stabiliser structure), the magnet system and the poloidal<br />

field coils. Since the maximum flat-top duration is 100 s, an actively cooled oxygen–free copper coil<br />

system has been chosen for the magnet. The cooling is guaranteed by pressurised sub-cooled<br />

(ΔT sat =26 nitrogen [LN 2 ]) flowing through suitable channels carved in the coil turns. Each turn is fed<br />

by LN 2 independently (the LN 2 flows in parallel in each turn) to limit<br />

the pressure drop to an allowable value and therefore avoid<br />

LN 2 vaporisation. The Ohmic power dissipated in the<br />

magnet is about 50 MW, which implies a LN 2 mass<br />

flow of about 1600 kg/s. The magnet consists of 18<br />

coils, each made up of 14 copper plates suitably<br />

worked in order to have 6 turns in the radial<br />

direction. Ripple correction is made by ferritic<br />

inserts. The 14 plates are welded corresponding to<br />

the most external region in order to obtain a<br />

continuous helix. The maximum turn thickness is<br />

30 mm. The plates are tapered at the innermost region<br />

to get the needed wedged shape; the minimum turn<br />

thickness is about 15 mm. The magnet insulation is made of<br />

Fig. A2.5 – FT3 Load assembly glass-fabric epoxy, both for ground and inter-turn.<br />

The coils are fixed together by the surrounding steel structure. Two pre-compressed rings situated<br />

in the upper-lower zone keep the whole toroidal magnet structure in a wedged configuration. The<br />

structure is also used to position the poloidal coils, which surround the toroidal magnet, and to fix<br />

the vacuum vessel supports. Cooling of the toroidal–magnet structure is obtained by the contact<br />

with the actively cooled components. To enable operation at 80 K, the whole machine is kept under<br />

vacuum by a metallic cryostat.<br />

The magnet dimensions were determined by the cooling requirements. It was necessary to limit the<br />

current density to 30 MA/m 2 . It turns out that from the structural standpoint the magnet section is<br />

adequate to sustain the forces. The first rough evaluation of the stresses indicates the maximum Von<br />

Mises to be below 200 MPa. The fabrication process is based on well–assessed technology utilised<br />

for FTU and other prototypical components, so no further R&D is required for the construction of<br />

the toroidal magnet.<br />

The FT3 free-standing central solenoid (CS) is segmented in six coils to allow plasma–shaping<br />

flexibility, to facilitate manufacture and to allow cooling. The poloidal field coils and busbars are made<br />

of hollow copper conductors. They have to withstand both vertical and radial electromagnetic loads,<br />

Progress Report 2006<br />

36


and are free to expand radially. The power to be removed from the poloidal field coils, keeping the coils at<br />

cryogenic temperature, is about 12 MW. The CS coils are layer wound and have an even number of layers<br />

for the electrical leads to be located on the same side of the coil. The conductors are wrapped with glass<br />

fabric and kapton tapes and vacuum impregnated with epoxy resin. Radial grooved plates at the interfaces<br />

between coil segments maintain concentricity. To limit the pressure drop, thus avoiding LN 2 evaporation,<br />

cooling is achieved by feeding each layer independently. Due to the large dimensions of the most external<br />

poloidal coils, a pancake configuration is adopted in order to allow cooling of the single turn. As for the<br />

toroidal magnet, the poloidal–coil section and conductor size were determined by the cooling<br />

requirements.<br />

The total FT3 LN 2 daily consumption, determined on the basis of four 100–s pulses a day or 16×10 s<br />

pulses, for the toroidal magnet and the poloidal coils is 150 t. A further consumption of 15 t for the losses<br />

through the ports and other feedthroughs as well as to keep the vacuum vessel at room temperature must<br />

be considered.<br />

The vacuum vessel is segmented by 20–degree modules. To minimise the vacuum vessel time constant,<br />

the shell is made of Inconel and the port in stainless steel. The maximum thickness of the shell is 30 mm,<br />

while the ports are 20 mm thick. The shell is manufactured by hot forming and welding. Following the<br />

previous experience with FTU, the vacuum vessel will be supported by the toroidal field magnet system by<br />

means of vertical brackets attached to the TF coil case through the vessel equatorial port. According to<br />

this constraint scheme, thermal expansion/contraction of the vessel is allowed, while nonsymmetric<br />

displacements that might appear during disruptions or plasma vertical displacement events are restrained.<br />

Twelve vacuum vessel sectors are equipped with five access ports. The maximum force during plasma<br />

disruption is about 300 t for a 5–MA operating scenario. The thickness of the wall is adequate to sustain<br />

such a load. The vessel time constant is about 30 ms. The operating temperature of the vessel ranges<br />

from room temperature to 100°C. A suitable water loop is dedicated to maintaining the vessel<br />

temperatures.<br />

The first wall and the divertor are actively cooled by pressurised water with velocity respectively 5 and<br />

10 m/s. These components have been designed to exhaust up to a maximum heat power of 50 MW<br />

during long pulse operation. The first wall surrounds most of the vessel wall. It consists of a bundle of tubes<br />

armoured with 3–mm plasma–spray tungsten. The heat load impinging on the first wall is, on average,<br />

1 MW/m 2 with a peak of about 3 MW/m 2 . The solution adopted is well suited to resisting these loads,<br />

having been tested up to 7 MW/m 2 . The first wall is also able to work as a limiter during plasma startup.<br />

Its temperature will be maintained around 100°C to avoid impurity adsorption. The design has to be<br />

remote-handling compatible. Maintenance will be carried out from equatorial and upper ports. The divertor<br />

has to withstand a heat flux in excess of 20 MW/m 2 . The only suitable technology in this case is<br />

monoblock, which has been tested extensively in the relevant heat flux range. The armour consists of<br />

hollow tungsten tiles inserted in a copper tube heat sink. The heat flux component will be supported by a<br />

steel frame which acts also as a cooling circuit. To enhance the critical heat flux, swirl tapes are provided<br />

in the most loaded zone. The configuration has to allow easy maintenance operation as the possibility of<br />

having to substitute some components is likely. The scheme is similar to that of ITER, with the frame acting<br />

as a carousel all around the machine. Maintenance will be carried out from the lower port.<br />

A remote handling system, similar to the JET FARM, has been conceived for unplanned (emergency)<br />

operations. Standard maintenance tasks will instead be accomplished by a plug-in design of the<br />

diagnostics and the antennae and casked solutions. The ITER divertor maintenance procedure will be used<br />

wherever possible. The procedure is based on the development of an ad hoc cassette–mover tractor<br />

capable of grasping and moving the divertor cassette. Some of the maintenance tasks of the first wall are<br />

similar to those foreseen for the divertor, so pipe sizes could be standardised to be able to share cut and<br />

weld devices. For the first wall assembly and disassembly a classical articulated boom plus a front end<br />

manipulator have been considered.<br />

Power supply. The FT3 power supply system includes three main subsystems: the 400–kV main<br />

switchyards, the poloidal field coil (PFC) power supplies and the toroidal field coil power (TFC) supplies.<br />

Figure A2.6 shows the total power for a 5–MA scenario with a total heating power of 30 MW<br />

37<br />

Progress Report 2006


A2 Preliminary Design of FT3<br />

Fig. A2.6 – Active, reactive and total power for the reference FT3 pulse<br />

A Fusion Programme<br />

P(MW) Q(MWAr) S(MVA)<br />

500<br />

400<br />

300<br />

200<br />

100<br />

P: active power<br />

Q: reactive power<br />

S: total power<br />

0<br />

-21 -15 -9 -3 0 6 12 18 24 30 36 42<br />

-100<br />

Time (s)<br />

(corresponding to about 80 MW requested at the<br />

grid) and a stationary load of 25 MW. Due to the<br />

amount of requested power, connecting to a<br />

powerful node of the 400–kV Grid would be<br />

desirable. Nevertheless, an accurate check by the<br />

National Grid Regulator (GRTN), including both<br />

active and reactive power effects on the specific<br />

grid, might show that a 220–kV line could be<br />

adequate. Lacking such an evaluation, the<br />

400–kV line is taken as the reference solution.<br />

Within the assumed 400–kV reference solution,<br />

FT3 needs a dedicated switchyard to supply the<br />

PFC, TFC, additional heating systems and<br />

auxiliaries. All the loads are fed by one main step–down transformer (400/36 kV) with three<br />

secondary windings: two (225 MVA each) star connected and grounded through a resistor, to supply<br />

FT3, and one (80 MVA) delta connected to allow free circulation of third harmonic currents. On the<br />

request of the GRTN, active power shedding resistors could be connected to the tertiary winding.<br />

Sharing the total power between two secondary windings has the aim of making it possible to use<br />

the 36–kV level on the secondary sides (instead of the more expensive 75–kV level), limiting the rated<br />

current within the present breaker capability at this voltage. Each circuit for the supply of the TFC and<br />

the various PFCs is generally made up of a converter transformer, a thyristor converter unit, a protective<br />

crow-bar and high-speed, solid–state switches for the additional resistance units. No specific study for<br />

the breakdown phase has been made so far.<br />

Table A2.III – ICRH system parameters<br />

Operating frequency range ( MHz) 60±90<br />

Peak power (MW) 20<br />

Bandwidth (MHz)<br />

±2MHz (-1db)<br />

Pulse width (s) ≥ 100<br />

Time interval between two<br />

100–s pulses (s) 1800<br />

Type of antenna<br />

3 rows of 2 straps<br />

Power per strap (MW)<br />

1 (at generator)<br />

Power coupled per antenna (MW) 5<br />

Max radiated power density (MW/ m 2 ) 10<br />

N. of antennae 4<br />

Power per generator (MW) 2<br />

N. of rf generators 12<br />

Heating systems. The FT3 auxiliary heating<br />

systems are consistent with the present state<br />

of the art and do not require additional R&D<br />

activity. FT3 is equipped with three systems:<br />

ICRH, ECRH and LHCD. A description of the<br />

ICRH system is given in table A2.III. At a<br />

magnetic field of 6.7 T, the use of 3 He minority<br />

requires a frequency of 68 MHz. In its initial<br />

configuration the system will couple 20 MW to<br />

the plasma. A possible design of the ICRH<br />

antennae could be based on an array of six<br />

(two toroidal by three poloidal) current straps<br />

protected by a Faraday shield made of a set of<br />

16 non–tilted elements, with a smoothed<br />

rectangular cross section. The Faraday shield<br />

has to suppress the components of the emitted radiation parallel to the local B-field, and shield the<br />

electrically active components from direct contact with the plasma. All the antenna components<br />

(straps and Faraday shield rods) are water-cooled. Each antenna is fed by three high–power<br />

tetrodes “TH 526”, with a maximum rf power output of 2 MW in the frequency range 35-80 MHz.<br />

Three of the generators are supplied by a 33–kV/380 A solid–state unit. The antenna, together with<br />

the respective vacuum transmission lines and vacuum windows, is integrated in a plug inserted in<br />

an equatorial port and removable as a single unit.<br />

The performance of the antenna was studied with the TOPICA code on the reference FT3 H–mode<br />

plasma scenario at 68 MHz with 2% 3 He minority. Electric current and magnetic current/electric field<br />

distribution were obtained in vacuum and with the plasma. The analysis in vacuum of the optimised<br />

antenna showed very good (low) inter-strap coupling. The analysis with plasma demonstrated the<br />

good performance of the antenna array in terms of power coupled to the plasma: for the standard<br />

configuration and for a maximum voltage of 30 kV, a power of 5 MW can be coupled to the plasma<br />

by each array. The launched power spectrum has a maximum for n || =±6. Figure A2.7 shows the<br />

current distribution on the straps, demonstrating the good efficiency obtained with this geometry:<br />

Progress Report 2006<br />

38


Fig. A2.7 – Distribution of current on the straps<br />

the current on the straps has a very high absolute value and is almost<br />

constant along the entire length of the straps.<br />

Four identical units compose the ECRH system, each with a gyrotron, a<br />

transmission line and a launcher. The four launchers are located in the same<br />

port. Each gyrotron is fed by an independent power supply, capable of<br />

high–frequency modulation (up to 10 kHz) and designed to be used as the actuator<br />

in the feedback loop for mode suppression. The power is delivered from the source to<br />

the launcher by means of an evacuated corrugated waveguide. The reference design for the launcher is<br />

based on front steerable mirrors, with real–time control of toroidal and poloidal injection angles. No barrier<br />

window is considered in the transmission line. The whole system is designed to operate in feedback mode<br />

with real-time control of the main parameters (polarization, beam current, mirror steering, power, fault<br />

management), addressing in this way technological issues relevant for a system working in a<br />

thermonuclear plant. The considered gyrotron is a 170–GHz/1–MW source, with depressed collector and<br />

a pulse length larger than 100 s, based on the results of the R&D activity for ITER. Each gyrotron is fed by<br />

a 55–kV/50–A high–voltage power supply. The transmission line is an evacuated aluminium corrugated<br />

waveguide (i.d. 63.5 mm) matched to the gyrotron output beam with an elliptical mirror. Since the power<br />

dissipated on the waveguide is small and the pulse length does not exceed 100 s, no direct cooling of the<br />

waveguide is considered, while all the other components (mitre-bends, polarizer, dc-break) must be<br />

cooled. The launcher under study, based on the front steering concept for major flexibility in terms of beam<br />

shaping and injection angles, is located in the upper vertical port. In this way, the intersection of the EC<br />

resonance with the q=2 surface, for the relative neoclassical teaning model (NTM) stabilisation, is reached<br />

with limited diffraction effects. The front mirror is real–time controlled at a speed compatible with all the<br />

issues assigned to the ECRH system (NTM stabilisation, sawtooth control, disruption mitigation). The beam<br />

spot radius (waist) in the plasma resonant region can be less than 3 cm, below the expected width of the<br />

NTM m/n=2/1 island at saturation. The overall losses of the design of ECRH system (waveguide, mitrebends,<br />

microwave components and launcher) are below 8%, which can be reduced further with a HE 11 to<br />

Gaussian beam converter at the beginning and at the end of the waveguide.<br />

The LHCD system is designed to routinely couple a rf power of 6 MW to<br />

FT3 plasmas. The preliminary design is based on a frequency of 3.7 GHz in<br />

pulsed regime, with pulse length up to 100 s. At this working frequency<br />

high–power CW sources are available, i.e., the TH 2103 klystron, rated at<br />

500 kW/CW and 650 kW/10 s; these klystrons (table A2.IV) are the<br />

sources of the Tore–Supra and JET LHCD systems. The FT3 LHCD system<br />

will be equipped with two passive–active multijunction (PAM) launchers,<br />

which will simultaneously allow coupling LH waves in the plasma with severe<br />

edge conditions and effectively water cool the antenna in long operations<br />

and with heavy thermal loads. The dimensioning of the launcher, given the<br />

frequency, is based on the requirement of launching a peak n || N ||peak =1.9<br />

and by the cross section of the FT3 ports at the narrower point. The<br />

Table A2.IV – TH 2103 main<br />

parameters<br />

resulting power density in the active waveguides is limited to P S =33 MW/m 2 , which is comparable with<br />

the values normally achieved in JET and Tore Supra.<br />

Taking into account ~20% rf losses in the transmission lines and in the launcher, a minimum rf power at<br />

the generator of P Inst =7.5 MW has to be installed, i.e., 15 klystrons to be used.<br />

Diagnostics. A specific activity has been dedicated to studying the capability of performing detailed<br />

measurements of the FT3 plasma parameters. The basic diagnostics include the magnetic diagnostic<br />

(diamagnetic loops, saddle coils, Hall sensors and pick–up coils), the CO 2 interferometer for measuring the<br />

electron density profile, the ECE (Michelson, polychromator and radiometer) and Thomson scattering<br />

systems for measuring the electron temperature, the bolometric measurements for plasma radiation,<br />

various spectroscopic measurements (visible, UV and x rays) of the impurity content, the neutron camera<br />

and neutron spectrometer for 2.45 neutron emission, the activation measurement and the gamma-ray<br />

scintillator. These diagnostics will be taken from FTU with minor adaptations. Further diagnostics could be<br />

provided as a contribution in kind from other associations. Discussions are under way to assess this<br />

possibility.<br />

ıJı (dB,interp)<br />

-11.540<br />

-14.704<br />

-17.869<br />

-21.033<br />

-24.198<br />

-27.362<br />

-30.527<br />

-33.691<br />

-36.856<br />

-40.020<br />

Frequency<br />

3.7 GHz<br />

Bandwidth @ - 1 dB 10 MHz<br />

Output power (CW) 500 kW<br />

Gain<br />

47 dB<br />

Cathode voltage<br />

60 kV<br />

Beam current<br />

20 A<br />

Efficiency 42%<br />

Modulating anode voltage 45 kV<br />

Modulating anode current 50 mA<br />

39<br />

Progress Report 2006


A3 Technology Programme<br />

A Fusion Programme<br />

The technology activities carried out by the Euratom-<strong>ENEA</strong> Association in the framework of the European<br />

Fusion Development Agreement (EFDA) concern the continuation of the ITER, DEMO and IFMIF R&D<br />

programmes. <strong>ENEA</strong> has also started design and preliminary R&D activities under the Broader Approach<br />

agreement between the EU and Japan.<br />

In 2006 the most important results of the technology programme were achieved in the fields of plasmafacing-component<br />

development and testing, neutron data, remote handling. However, it should be noted<br />

that all the activities contributed substantially to the progress of the fusion programme as a whole (safety,<br />

the Power Plant Conceptual Study, engineering activities).<br />

The divertor CFC/W monoblock mockup fabricated using <strong>ENEA</strong>’s patented processes was tested under<br />

fatigue heat loads and achieved results that surpassed those of the other technologies. The next step is to<br />

industrialise the technology for application in the construction of the ITER divertor heat flux components.<br />

Significant work was done to define quality assurance for neutronics analyses. Mockups of the ITER precompression<br />

ring made in glass fibre epoxy were fabricated.<br />

<strong>ENEA</strong> is also equipped to contribute to the ITER construction, not only through the continuing R&D<br />

activities, but also through participation in the development of the ITER neutron radial camera and laser invessel<br />

viewing system and, as an associate of the Consortium of Associations, in the construction of the<br />

first nuclear fusion components - the Test Blanket Modules.<br />

The activities and results documented in the following illustrate <strong>ENEA</strong>’s readiness to enter the new era<br />

opened with the decision to build ITER.<br />

A3.2 Divertor, First Wall, Vacuum Vessel and Shield<br />

Manufacturing of small-scale W monoblock mockups<br />

Manufacturing of the prototypical component by means of the two <strong>ENEA</strong> patented technologies<br />

(pre-brazed casting [PBC] and hot radial pressing [HRP]) was successfully concluded (Underlying<br />

Technology and European Fusion Development Agreement contract [EFDA] 03/1054) [A3.1-A3.5].<br />

Thermograph non-destructive (ultrasonic, lock-in thermography) testing performed with the SATIR<br />

(Commissariat à l’Energie Atomique ([CEA]) equipment showed there was no evidence of defective<br />

zones. After the testing the mockup was sent to the FE200 e-beam facility at Le Creusot France for<br />

thermal fatigue tests (fig. A3.1).<br />

The testing plan started with a screening at 5 MW/m 2 of absorbed power. The mockup was<br />

successfully tested at ITER-relevant heat fluxes: 10 MW/m 2 for 3000 cycles (all), 20 MW/m 2 for<br />

2000 cycles on the carbon fibre composite (CFC) part, 15 MW/m 2 for 2000 cycles on the tungsten.<br />

Progress Report 2006<br />

40


Fig. A3.1 – Monoblock mockup installed in the FE200<br />

facility before high heat flux testing<br />

Figure A3.2 shows the infrared images taken during<br />

the high heat flux testing and during the 3176 th<br />

cycle performed at 20 MW/m 2 of absorbed power<br />

on the CFC tiles and 15 MW/m 2 on the tungsten.<br />

The images highlight the absence of surface<br />

overheating. The mockup was also subjected to<br />

critical heat flux (CHF) (fig. A3.3) to verify its<br />

behaviour under ITER-relevant thermal-hydraulic<br />

conditions. A CHF of 35 MW/m 2 was obtained and<br />

it can be said that this value is well above that<br />

estimated and gives a margin of 1.75 with regards<br />

to ITER nominal loading. For the first time it was<br />

possible to measure the CHF of a monoblock<br />

component with armour tiles still joined on the tube.<br />

Figure A3.4 shows the mockup after the CHF<br />

testing, while still connected to the FE200 facility.<br />

Fig. A3.2 – a) CFC part, b) W part<br />

10/19/06 INFRAMETRICS 17:59:19<br />

The complete manufacturing and successful testing<br />

of this vertical target medium-scale mockup<br />

(fig. A3.5) can be considered a success for both the<br />

PBC and the HRP processes. A survey of the<br />

manufacturing technologies for the ITER divertor<br />

has shown that they are valid alternatives to the<br />

current techniques.<br />

2353<br />

1997<br />

2195 2098 1981<br />

Fig. A3.3 – Infrared image during CHF testing at 34.2 MW/m 2<br />

Fig. A3.4 – CFC surface after CHF testing<br />

[A3.1] M. Merola et al., Fusion Eng. Des. 56-57, 173 (2001)<br />

[A3.2] M. Rödig et al., Fusion Eng. Des. 56-57, 417 (2001)<br />

[A3.3] M. Rödig et al., Investigation of tungsten alloys as plasma facing materials for the ITER divertor, presented at the 6 th Int. Symposium on<br />

Fusion Technology - ISFNT-6 (San Diego 2002)<br />

[A3.4] E. Visca et al., Fusion Eng. Des. 56-57, 343 (2001)<br />

[A3.5] M. Rödig et al., Post irradiation testing of samples from the irradiation experiments PARIDE 3 and PARIDE 4, presented at the 11 th Inter.<br />

Conference on Fusion Reactor Materials - ICFRM-11 (Kyoto 2003)<br />

References<br />

41<br />

Progress Report 2006


A3 Technology Programme<br />

Engineering Design Activities: V<br />

and VI test campaigns<br />

A Fusion Programme<br />

Fig. A3.5 – Mockup after thermal fatigue testing (high heat<br />

flux testing [HHFT] and CHF)<br />

Fig. A3.6 – Mockup PH-S-39 B being tested in EDA-<br />

BETA apparatus<br />

The objective of the test campaigns in the<br />

framework of Engineering Design Activities<br />

(EDA) is to characterise the primary first-wall<br />

(PFW) panels in terms of their behaviour<br />

under thermal fatigue in ITER-relevant<br />

conditions (temperature and thermal flux).<br />

Thermal fatigue tests on the PFW mockups<br />

under ITER-relevant operative conditions<br />

were carried out to qualify the Be-metallic<br />

heat sink (Cu alloys)-austenitic 316L steel<br />

panel joints made by hot isostatic pressing.<br />

In 2006 the EDA V campaign was<br />

successfully concluded, with neither melting<br />

nor erosion/failure of the Be tiles. Under the<br />

new EDA VI campaign, started in late<br />

autumn, the plan is to accomplish 30000<br />

thermal cycles. As in the previous<br />

campaigns, the two mockups (one shown in<br />

fig. A3.6) delivered to <strong>ENEA</strong> by EFDA, are<br />

being tested under thermal fatigue cycling<br />

with an emitted thermal flux up to a<br />

maximum of 0.65 MW/m 2 and a cycle<br />

period of 300 s. The EDA-BETA<br />

experimental setup (fig. A3.7), consisting of<br />

a glove box operated under vacuum and<br />

suitably instrumented (with a high specific<br />

power CFC resistor), is connected to the<br />

CEF 2 water loop at <strong>ENEA</strong> Brasimone for the<br />

mockup cooling. The main features of the<br />

whole experimental apparatus (EDA-BETA +<br />

CEF 2) are summarised in table A3.I. The<br />

experimental activity should be concluded in<br />

late summer 2007.<br />

Fig. A3.7 – The two mockups assembled in EDA-<br />

BETA apparatus<br />

Hydraulic characterisation of<br />

full–scale divertor components<br />

Table A3.I – EDA-BETA + CEF 2<br />

The main aim of the activity, started in 2006,<br />

EDA-BETA dimensions (Φ×l)<br />

700×1200 mm is to perform an exhaustive thermal<br />

Max. power delivered by the resistor 41 kW<br />

hydraulic experimental campaign on the<br />

ITER divertor plasma-facing components<br />

Max. thermal flux emitted by the resistor 0.65 MW/m 2<br />

(PFCs), i.e., outer vertical target (OVT),<br />

Loop design temperature 140 °C<br />

dome liner (DL) and inner vertical target (IVT)<br />

Max. CEF1 pump flow-rate<br />

2×70 kg/s<br />

in stationary state and transient conditions.<br />

Max. pump head<br />

2×1.2 MPa<br />

Both types of tests are carried out in the<br />

CEF 1 water loop at <strong>ENEA</strong> Brasimone.<br />

Hydraulic tests in stationary state are aimed at determining the pressure drop of each component,<br />

verifying the balance of the parallel water flows and assessing possible conditions for the insurgence<br />

of cavitation. The tests on the OVT and DL were successfully carried out in the last part of 2006.<br />

Figure A3.8 shows the OVT connected to the CEF 1 loop. Figure A3.9 reports the pressure drops<br />

across the OVT, experimentally determined at three different temperatures (20-50-100°C). Tests in<br />

transient conditions are aimed at evaluating the efficiency of discharging the activated water, not<br />

Progress Report 2006<br />

42


Pressure drop (bar)<br />

5.0<br />

4.0<br />

3.0<br />

2.0<br />

1.0<br />

0.0<br />

20°C<br />

80°C<br />

50°C<br />

100°C<br />

y=0.0228x1.8223<br />

R 2 =1<br />

y=0.0188x1.8809<br />

R 2 =0.9998<br />

y=0.0171x1.9083<br />

R 2 =0.9997<br />

y=0.0174x1.881<br />

R 2 =0.9996<br />

5 8 11 14 17 20<br />

Water flow (kg/s)<br />

Fig. A3.8 – OVT connected to CEF 1 loop<br />

Fig. A3.9 – Pressure drops across OVT<br />

drainable by gravity, into the divertor modules. The procedure 30<br />

to efficiently accomplish this task has been identified as 20<br />

consisting of a first phase of draining by high-pressure gas,<br />

10<br />

followed by drying of the residual water by low-pressure dry<br />

gas. This part of the experimental activity requires up-grading<br />

0<br />

6/3 20/3 35/3 45/3 55/3 60/3 75/3 85/3 110/3<br />

of the CEF 1 loop: most of work on the technical<br />

specifications and on the design and construction activities<br />

Ratio H 2 /H 2 O<br />

has been done and will be concluded in early spring 2007. Fig. A3.10 – EUROFER experimental results in terms<br />

<strong>ENEA</strong> Brasimone and the University of Palermo are of PRF as a function of the ratio H 2 /H 2 O<br />

collaborating on validating a thermal-hydraulic code through<br />

correlation with the experimental results for both types of<br />

test. Once validated on the basis of the experimental results achieved, the<br />

code will be used to predict the behaviour of the single components of the<br />

ITER divertor as well as the integrated divertor cassette, in fully relevant<br />

operative conditions and component geometry.<br />

PRF<br />

H permeation through EUROFER and heat exchanger<br />

material (Incoloy, Inconel)<br />

In 2006 the PERI 2 device was modified. A more precise quadrupole was<br />

adopted and the mixing-gas system, with a mass flow meter on the Ar line,<br />

a mass flow controller on the H/D line and a gas humidifier and humidity<br />

measuring system, was moved from the low- to the high-pressure side. After<br />

start-up of the modified device, tests with deuterium were begun, using a<br />

ratio of three between deuterium and water. The experiment gave no<br />

appreciable results: after a few seconds, there was a reduction in the Fig. A3.11 – Removal of the inner<br />

permeated hydrogen flux but, continuing the experiment, this effect was vertical target<br />

annulled and the flux reached the steady-state value. Tests were performed<br />

with EUROFER in accordance with the test matrix, using hydrogen instead of deuterium. This solution was<br />

adopted as the new quadrupole demonstrated high precision in measuring hydrogen concentration, unlike<br />

the old instrument. A precise range of water/hydrogen mixtures in which the permeation reduction factor<br />

(PRF) is appreciable was identified, and the campaign on EUROFER was concluded. Experimental results<br />

obtained in terms of PRF are reported in figure A3.10.<br />

Formal trials for the new ITER divertor cassette refurbishment<br />

Since the divertor cassettes need to be replaced and updated several times during the ITER lifetime,<br />

refurbishment of these components must be performed rapidly and with a high standard of safety. To<br />

assess the feasibility of such refurbishment operations a test campaign consisting of two complete<br />

assemblies and disassemblies (fig. A3.11) of the three PFCs, also called targets, was performed during<br />

43<br />

Progress Report 2006


A3 Technology Programme<br />

A Fusion Programme<br />

2006. The trials were aimed at validating the procedures already developed as well as evaluating the<br />

suitability of the present cassette design (i.e., new ITER 2001 divertor cassette) for remote handling.<br />

According to the results of the tests, the assembly process appears to be better than the<br />

disassembly process. In fact the tool used for pin extraction was not correctly dimensioned and<br />

hence target disassembling operations were carried out hands on. At present the tool design is<br />

under revision. The other tools developed, such as the plasma-facing-component transporter<br />

(PFCT), the pin expansion tool (PET) and the drilling machine, fulfil the specification requirements.<br />

The activities were completed in July 2006.<br />

A3.3 Breeder Blanket and Fuel Cycle<br />

DEMO breeding blanket<br />

Work continued on the development of the dual coolant lithium lead (DCLL) concept and the<br />

possibility of having a vertical module segmentation (VMS) for the blanket [A3.6, 3.7]. The results<br />

have pointed out the potential of the DCLL blanket to operate in the required DEMO environment<br />

with allowable temperatures and stresses. The VMS studies showed a gain in reducing the electromagnetic<br />

loads during disruption, therefore reducing the requirements for the support structure. The<br />

results of dimensioning of the supports and studies on the kinematics in the vessel showed that it<br />

might be possible to replace the whole blanket using a reasonable number of ports. The ports are<br />

being studied in relation to the hypotheses on the DEMO magnets.<br />

European Breeding Blanket Test Facility<br />

Throughout 2006 <strong>ENEA</strong> was strongly involved in R&D activities for both the helium-cooled pebble<br />

bed (HCPB) and the helium-cooled lithium-lead (HCLL) test blanket modules (TBMs) to be tested in<br />

ITER. The work was focussed on i) experimental activities related to the development of relevant<br />

technologies and ii) the design, construction and upgrading of the experimental facilities, which will<br />

allow <strong>ENEA</strong> to retain the EU leadership in the field of experimentation on TBMs.<br />

The construction of the liquid metal loop was started in April 2006. The reference parameters, fixed<br />

in the design phase, are volumetric flow rate 0.03-0.9 m 3 /h; maximum temperature 550°C;<br />

minimum temperature 300°C; thermal cycling 400 s T max , 1400 s T min ; liquid metal inventory in the<br />

module 0.4 m 3 ; liquid metal inventory in the loop, including the TBM, 0.6 m 3 ; cover gas argon. The<br />

main modifications foreseen to upgrade HEFUS3 are a new water heat exchanger of 900 kW and a<br />

new electric power supply unit of 1 MW, in order to provide 250 kW of electrical power to the first<br />

wall and 750 kW to the breeding region of the TBM mockups. HEFUS3 will be equipped with a new<br />

He compressor capable of reaching a maximum He flow-rate of 1.4 kg/s with a head of 0.9 MPa.<br />

Its installation is foreseen for late 2007. In 2006 the technical specifications for the HEFUS3<br />

upgrading were prepared. The conclusion of the activity, with the installation of the above-mentioned<br />

modifications, is scheduled for the end of 2007.<br />

Thermo-mechanical characterisation of HCPB mockup<br />

The thermo-mechanical behaviour of the breeder and neutron multiplier pebble bed in reactorrelevant<br />

conditions is one of the main concerns in the design of the HCPB blanket for DEMO and<br />

the TBM to be tested in ITER. Hence, experimental results and predictive models are of basic<br />

importance in developing this blanket concept. During 2006 the HELICA mockup was dismounted<br />

and the OSi pebbles recovered. The pebbles were “filtered” and the production of powder, after 34<br />

thermal ramps, quantized in 4%. Scanning electron microscopy (SEM) examinations (fig. A3.12) of<br />

the pebbles showed that they kept their physical integrity. A new experimental setup was designed<br />

for thermo-mechanical characterisation of the HEFUS3 experimental cassette of the lithium-<br />

Progress Report 2006<br />

44


Fig. A3.12 – SEM of HELICA OSi pebbles<br />

beryllium pebble bed (HEXCALIBER) mockup, designed and<br />

manufactured to reproduce a portion of the former TBM-HCPB<br />

with two OSi and two beryllium pebble bed cells, both heated<br />

by couples of flat electrical heaters (figs A3.13). The mockup will<br />

be tested in 2007 in the HEFUS3 facility, under appropriate<br />

adjustment of bed temperatures, temperature gradients,<br />

coolant temperatures, flow distributions and mechanical<br />

constraints, to assess the thermo-mechanical performance of<br />

the pebble beds under steady-state and cyclic-heat power<br />

conditions. To perform the test campaign in safety, avoiding any<br />

possible Be contamination, the whole experimental setup was<br />

designed at a pressure of 2.0 MPa and a temperature of 500°C<br />

and equipped with three independent helium circuits: one circuit<br />

for the cooling plates of mockup, and two purge flow circuits for<br />

OSi and Be beds, a vacuum system, and a double oil guard.<br />

Each circuit will have units for filtering and monitoring the Be<br />

powders. A preliminary study of the HEXCALIBER mockup<br />

thermo-mechanical behaviour under steady-state conditions<br />

was performed in the framework of the benchmark exercise to<br />

select the best constitutive model for thermo-mechanical<br />

prediction of pebble bed behaviour under blanket-relevant<br />

conditions, among those developed by <strong>ENEA</strong><br />

Brasimone/University of Palermo, the Nuclear Research<br />

Consultancy Group (NRG) Petten and Forschungszeuntrum Karlsruhe (FZK). In particular, a realistic 3D finite<br />

element model (FEM) of HEXCALIBER (fig. A3.14), simulating a 1-cm-thick slice of the whole mockup, was<br />

developed. A realistic set of loads and boundary conditions was applied, taking into account natural<br />

convection with air, forced convection with helium coolant (T=300–400°C, p= 8 MPa) and distributed<br />

electric heat generation within the heating plate electric resistors. A thermal contact model was implemented<br />

at the interface bed-wall and bed-heater, where no mechanical sliding was assumed. Poloidal plain strain<br />

was assumed to simulate the continuity of the mockup in that direction. The thermal field obtained matches<br />

the prefixed goals, showing in each pebble bed the expected trapezoidal poloidal profile with the flat portion<br />

located in the pebble bed layer<br />

between the heating plates. A<br />

decreasing radial profile from the<br />

centre to the extremity of the bed<br />

can be seen in each pebble bed.<br />

Maximum temperatures of 819<br />

and 563°C have been calculated<br />

for the OSi and the Be pebble<br />

bed, respectively. Analysis of the<br />

mechanical volumetric strain field<br />

within the beds shows that they<br />

experience only compressive<br />

strain states. The highest<br />

mechanical strains are reached<br />

within the OSi pebble beds and<br />

are (≈0.17) one order of<br />

magnitude higher than in Be<br />

beds.<br />

NT11<br />

+8.300e+02<br />

+7.934e+02<br />

+7.569e+02<br />

+7.203e+02<br />

+6.837e+02<br />

+6.471e+02<br />

+6.106e+02<br />

+5.740e+02<br />

+5.374e+02<br />

+5.009e+02<br />

+4.643e+02<br />

+4.277e+02<br />

+3.911e+02<br />

+3.546e+02<br />

+3.180e+02<br />

Max +8.292e+02<br />

at node PART-1-1.15106<br />

Min +3.197e+02<br />

at node PART-1-1.958<br />

Acc.V Spot Magn Det WD Exp 500 μm<br />

20.0 kV 5.0 50x SE 15.9 823 PM13206 Li4SiO4 Helica 2>138 μm<br />

A<br />

A<br />

Fig. A3.13 – HEXCALIBER mockup<br />

z [m]<br />

0.225<br />

0.125<br />

0.025<br />

400 600 800<br />

T (°C)<br />

Fig. A3.14 – HEXCALIBER FEM model: thermal field and its poloidal profile along<br />

the path A–A<br />

[A3.6] C. Nardi, S. Papastergiou and A. Pizzuto, Development of DCLL blanket, <strong>ENEA</strong> Internal Report FUS-TEC BB MC R 0016 (2006)<br />

[A3.7] C. Nardi, S. Papastergiou and A. Pizzuto, DEMO blanket segmentation, <strong>ENEA</strong> Internal Report FUS–TEC BB MC R 0017 (2006)<br />

References<br />

45<br />

Progress Report 2006


A3 Technology Programme<br />

A Fusion Programme<br />

Table A3.II – EFDA-approved text matrix<br />

Test Temperature Pb Li flow rate Stripping Ar flow rate<br />

no (°C) (kg/s) (Nl/h)<br />

TRIEX loop for studying<br />

technologies for extracting<br />

tritium from Pb-17Li<br />

1 450 0.2 10<br />

The first year of activity with the<br />

2 450 0.5 100 (150)<br />

TRIEX loop, delivered to<br />

3 450 0.35 55 (80)<br />

Brasimone at the end of 2005,<br />

4 450 0.2 100 (150)<br />

was dedicated to loop<br />

5 450 0.5 10<br />

acceptance tests and<br />

6 450 0.35 55 (80)<br />

qualification of the main installed<br />

components (pump, gas<br />

saturator, gas extractor by packed column). The first test campaign with a test matrix agreed on by<br />

EFDA and other EU Associations will be performed in 2007. To verify the Pb-Li pump performance,<br />

the loop was operated without the stripping gas flowing in the expected operative Pb-Li flow rate<br />

range between 0.1 to 1 kg/s. Varying the Pb-Li mass flow rate, the attainment of 500°C as<br />

maximum operative temperature was also evaluated to check the loop electrical heating system.<br />

Then, the Ar gas system injection was operated to check the Pb-Li levels in the saturator and<br />

extractor by using the gas mass flow control systems of the facility. After loop qualification the real<br />

experimental activities will start with a first experimental test campaign and an optimised test matrix,<br />

obtained by adopting a factorial method developed by CEA to better exploit each test, optimise the<br />

test para meters and consequently to reduce the total number of tests. Table A3.II reports the test<br />

matrix approved by EFDA. The experimental activities will be concluded at the end of 2007.<br />

Conceptual design of auxiliary systems for HCPB-TBM<br />

The possibility to recover with high efficiency the tritium generated in the HCPB blanket as well as<br />

the fraction permeated into the He main cooling system is one of the main objectives of the blanket<br />

test campaign planned in ITER. In summer 2006 <strong>ENEA</strong> was charged by EFDA with studying the<br />

selection and conceptual design of the tritium extraction system (TES) and coolant purification<br />

system (CPS) for the HCPB TBM. For both systems the activity consists in determining the inlet gas<br />

composition during the different ITER operational phases, examining all the technological options<br />

and selecting the most suitable and, finally, proposing a first conceptual design.<br />

Both the TES and the CPS are based on the technology of physical adsorption on microporous<br />

materials in different system configurations (pressure temperature swing adsorption (PTSA), TSA,<br />

PSA), integrated with other systems which, depending on the process requirement, makes it possible<br />

to reduce HTO in HT (Zn or Zn-Fe-Mn reactors) or, on the contrary, to oxidise HT to HTO (Cu 2 O-CuO).<br />

Structural analyses during em loading<br />

For the TBM with the HCPB concept, numerical models have been developed to take into account<br />

the presence of pebble beds during electromagnetic (em) transient structural analyses. The em force<br />

distribution increases to an asymptotic maximum and then drops exponentially to null. These loads<br />

can produce oscillations in the TBM structures when the force disappears, or no oscillations if the<br />

damping is large enough. Hence it is necessary to analyse the behaviour (stiffening and inertial) of<br />

the beds during such a quick transient load (30-100 ms), differently from the “low-velocity” models<br />

used up to now for thermal cycling modelling.<br />

The presence of pebble beds inside the TBM is analysed though the definition of two representative<br />

simplified models of the complete structure: 1) a submodel of the grid structure; 2) a submodel of a<br />

breeder unit. The steel components are assumed to behave linearly elastic, while the modified<br />

Drucker-Prager model is implemented for the mechanical characterisation of the pebble layers. The<br />

results of oedometric tests for the beryllium pebble beds are used to calibrate the parameters of<br />

such a constitutive relationship. On the basis of the numerical simulation it is possible make the<br />

Progress Report 2006<br />

46


following considerations: a) The pebble layers have a moderate effect on the structural behaviour of the<br />

TBM components if shear deformation is dominant. In this case, the volume reduction of the TBM cavities<br />

and, thus, the compaction of the pebble beds are negligible. As a consequence, the stress state in the<br />

steel frame undergoes minor variations when the granular filler is considered in the numerical model. b)<br />

When the deformation of the steel frame during em loading acts in such a way as to produce compaction<br />

of the pebble beds, their effects become much more significant: the presence of a filler material produces<br />

a sensible increase in the structure stiffness and, at the same time, the stress field is redistributed within<br />

the steel frame. Usually, when the pebble beds are included in the model the stress intensity is less critical<br />

compared with the case of the empty frame (without pebble material). Nevertheless, em loading can induce<br />

high stresses in regions not designed to bear them.<br />

VDS catalyst tests<br />

Samples of Plexiglas, Polyvinyl chloride, vacuum pump oil and Teflon were burnt at 200°C in a 1 m 3 oven<br />

(fig. A3.15) and the combustion fumes were sent onto catalytic beds consisting of platinum on Al 2 O 3 (Escat<br />

26 furnished by Engelhard). The aim was to reproduce the case of a fire in the tritium laboratory of ITER<br />

Fig. A3.15 – Materials used in the combustion tests: a-b) Plexiglas, c-d) PVC, e-f) vacuum pump oil with Teflon<br />

47<br />

Progress Report 2006


A3 Technology Programme<br />

Fig. A3.16 – View of the PERMCAT module (above) and the<br />

Pd-Ag thin–wall permeator tube (below)<br />

A Fusion Programme<br />

and to study the poisoning of the catalyst of the<br />

vent detritiation system (VDS). The test results<br />

show that the combustion fumes of PVC, pump oil and Teflon could affect the Pt-based catalyst<br />

efficiency even if, under the operating conditions of the VDS, all the tritiated gases (HT) are<br />

converted into tritiated water [A3.10].<br />

Permeator tubes<br />

The PERMCAT reactor module designed by <strong>ENEA</strong> has been completed (fig. A3.16). This device has<br />

a special mechanical design in which two pre-tensioned metal bellows avoid any compressive and<br />

bending stresses of the thin-walled (50 μm), long (500 mm) Pd-Ag permeator tube produced via<br />

cold rolling and diffusion welding of metal foils [A3.8, A3.9].<br />

A3.4 Magnet and Power Supply<br />

ITER magnet casing welds<br />

The tests performed at ASG Superconductors Genoa to verify the use of electron beam welding<br />

procedures to perform the root weld for the ITER magnet casings (in AISI 316 LN modified with high<br />

nitrogen content) showed that, using the welding apparatus in ASG and the proposed welding<br />

procedures, it is not possible to weld a 40-mm thickness of this material [A3.11].<br />

ITER pre-compression ring fibreglass composite material<br />

A new batch (VR 5) of unidirectional fibreglass composite has been produced in the new kettle. The<br />

increase in the active length of the kettle allowed the production of 650-mm-long samples, which<br />

were tested with the use of the grip system (45’ fibreglass grips kept in place by 15 Inconel<br />

compression rings in) at room temperature (RT) and 77 K (5 samples per temperature). The results<br />

showed that the mean value of the ultimate tensile strength was 2200 MPa at RT and 2766 MPa at<br />

77 K. In both test sets the dispersion in the values of the mechanical characteristics (ultimate<br />

strength, elasticity modulus and fracture elongation) was very low, the maximum being lower than<br />

3% of the mean value [A3.12]. Relaxation tests are envisaged for 2007.<br />

High-frequency/high-voltage solid-state modulator for ITER gyrotrons<br />

Activities regarding construction and testing of the solid-state modulator (EFDA contract 02-686)<br />

were successfully completed during the first months of 2006. At the same time, a new task was<br />

started on design support and digital simulation of the entire power supply system for the European<br />

collector depressed potential (CDP) gyrotron test.<br />

A3.5 Remote Handling and Metrology<br />

In the sharing of the in-kind contributions to ITER, the EU is to procure the in-vessel viewing and<br />

ranging system (IVVS), which has to be able to provide sub-millimetric 3D images inside the<br />

activated machine. Results of the relative R&D performed during the last six years have shown that<br />

Progress Report 2006<br />

48


Fig. A3.17 – IVVS Probe<br />

Table A3.III – IVVS operating conditions<br />

Temperature 250°C<br />

Vacuum<br />

10 -9 mbar<br />

Magnetic field<br />

5 T<br />

γ Radiation (rate/total) 1.5 kGy/h; 5 MGy<br />

Viewing&ranging accuracy


A3 Technology Programme<br />

A Fusion Programme<br />

be noted that the<br />

requested viewing<br />

and ranging per -<br />

formances are fully<br />

met for both. The<br />

Thermally stressed zones<br />

749.0<br />

viewing performance<br />

795.8<br />

was compared with a<br />

standard resolution<br />

chart, while ranging<br />

accuracy was<br />

identified as the<br />

605.1<br />

604.1<br />

standard deviation of<br />

all the ranging<br />

measure ments. The<br />

IVVS probe was<br />

characterised by<br />

defining ranging<br />

accuracy vs the<br />

Fig. A3.19 – Viewing and ranging test on ITER DVT metal side (d=2 m; ranging<br />

backscattered power<br />

accuracy standard deviation σ < 1 mm)<br />

received by the<br />

probe. The experimental results fully comply with the theoretical expectations. The ITER operator will<br />

have a friendly tool to easily evaluate the expected accuracy according to the target position and<br />

characteristics. Possible probe modifications (increasing laser power and modulating frequency)<br />

were identified in order to upgrade the present performance by about a factor of 10.<br />

mm<br />

306.0 pixels<br />

294.0 pixels<br />

A3.6 Neutronics<br />

Quality assurance for neutronics analysis for ITER<br />

mm<br />

342.0 pixels<br />

348.0 pixels<br />

Quality assurance (QA) procedures for neutronics analyses (task TW5-TDS-NAS1–D1) were drawn<br />

up in collaboration with the ITER Responsible Officers for Neutronics and for the Management and<br />

Quality Programme. The final version of the procedures, applicable to the ITER Central Team and to<br />

external suppliers, was issued on the basis of feedback received, and loaded on the ITER<br />

Documentation Management (IDM) system [A3.13]. As a test case the procedures were applied in<br />

a neutronics task order implemented by EFDA on the ITER diagnostic plug analysis, and the<br />

application was monitored. A series of actions was also undertaken to assess and provide<br />

adequate instruments for the QA procedures. First, the status of the MCNP brand model for<br />

neutronics analyses of ITER was reviewed. It was found that there were many outdated models that<br />

contained significant differences as they had been developed for various specific purposes, so an<br />

up-to-date reference model was produced and made available, and the reference materials<br />

specified in the model were reviewed. According to QA procedures, computer software for<br />

neutronics calculations has to be verified and validated prior to use. Codes were identified that had<br />

already been verified and validated during the ITER EDA R&D activities and can be used in the ITER<br />

neutronics analyses and calculations. The related documentation was collected. However, other<br />

codes, or new versions of codes, may be developed for specific purposes: a verification/validation<br />

procedure was worked out for these cases and applied to code packages under development, such<br />

as CAD-MCNP interfaces, Attila code and D1S, R2S package (MCNP-FISPACT coupled) for dose<br />

rate calculations. Three separate validation efforts were launched for the Fusion Evaluated Nuclear<br />

Data Library (FENDL)-2.1, selected as the reference library for ITER. <strong>ENEA</strong> and the Japan Atomic<br />

Energy Agency (JAEA) conducted the analysis of experimental benchmarks performed at the<br />

Frascati Neutron Generator (FNG) and the Fusion Neutron Source (FNS), respectively, during ITER<br />

Engineering Design Activities (EDA), and FZK conducted a computational benchmark on a simplified<br />

ITER geometry.<br />

Progress Report 2006<br />

50


Finally, the ITER Nuclear Analysis Report (NAR) was reviewed and the parts that need to be updated were<br />

identified. As a general result, it was found that new calculations are needed for many components, taking<br />

into account the present design. A table of contents has been written for the next issue of the NAR.<br />

Compared to the previous NAR structure, more emphasis will be given in the new issue to the components<br />

rather than to the models used.<br />

ITER systems: nuclear design<br />

The activity was focussed on interfaces for divertor sensors and optical elements in the divertor cassette<br />

and lower ports, the design and integration of the sensors and optical access and on a review of divertor<br />

integration issues for the various diagnostic systems. In particular, work was carried out on the interface<br />

and integration issues of the new “Divertor 2006 Design” of the neutron diagnostics (lower vertical neutron<br />

camera and divertor neutron flux monitors) of the optical systems (divertor impurity monitor and divertor<br />

Thomson scattering) and the residual gas analyser systems, taking into account possible locations in ITER<br />

divertor, detectors/techniques, vacuum and magnetic field interferences, radiation, cooling and<br />

cabling/power supplies. Calibration issues/schemes of the neutron systems and related integration<br />

engineering aspects were studied to identify the ITER in-situ neutron calibration procedures. The rationale,<br />

requirements, specifications concerning the neutron test area (NTA) and the NTA-hot cell system<br />

integration issues were reviewed. The NTA is a laboratory for inspection trials, calibration, commissioning,<br />

cross checking and support of neutron diagnostic sensitive devices and equipment during all the<br />

functioning periods (assembly, operation, shutdowns, maintenance) of ITER [A3.14, A3.15].<br />

TBM HCPB and HCLL neutronics experiments<br />

In 2006 the neutronics experiment on a mockup of the European Union TBM, HCPB concept was<br />

completed [A3.16, A3.17]. The aim was to validate the capability of nuclear data to predict nuclear<br />

responses, such as the tritium production rate (TPR), with qualified uncertainties. The experiment was<br />

carried out at the FNG 14-MeV neutron source in a collaboration between <strong>ENEA</strong>, the Technical University<br />

of Dresden (TUD), FZK and the Joseph Stefan Institute of Ljubljana, with the participation of JAEA under<br />

the International Energy Agency (IEA) Implementing Agreement on a Co-operative Programme on the<br />

Nuclear Technology of Fusion Reactors. A slight underestimation was found in the calculation of tritium<br />

production in the range (1–C/E)~5...10% on average. The resulting total uncertainties on C/E for the TPR<br />

prediction were about 9 – 10% at 2σ level [A3.18]. The observed underestimation of the measured tritium<br />

production by less than 10% on average is therefore at the lower bound of the assessed uncertainty<br />

margin. Behind the mockup, the fast neutron flux (E>1 MeV) was found to be overestimated by<br />

calculations by about 10–20%, while the gamma-ray flux is underestimated by about 10-20% [A3.19,<br />

A3.20]. The slow neutron flux investigated by time-of-arrival spectroscopy is also underestimated by<br />

[A3.13] P. Batistoni, Quality assurance in neutronic analyses (May 2006), https://users.iter.org/users/idm?document_id=ITER_D_23H9A4<br />

[A3.14] G. Bonheure et al., Nucl. Fusion 46, 725 (2006)<br />

[A3.15] A. Costley et al., The design and implementation of diagnostic systems on ITER, presented at the 21 st Inter. Atomic Energy Agency (IAEA)<br />

Fusion Energy Conference (Chengdu 2006)<br />

[A3.16] P. Batistoni et al., Fusion Eng. Des. 81, 1169 (2006)<br />

[A3.17] U. Fischer et al., Neutronics and nuclear data for fusion technology - recent achievements in the EU programme, presented at the 21 st<br />

IAEA Fusion Energy Conference (Chengdu 2006)<br />

[A3.18] P. Batistoni et al., Neutronics experiment on a HCPB breeder blanket mock-up, presented at the 24 th Symposium on Fusion Technology<br />

- SOFT-24 (Warsaw 2006), accepted for publication in Fusion Eng. Des.<br />

[A3.19] K. Seidel et al., Measurement and analysis of neutron flux spectra relevant to the tritium breeding capability in a neutronics mock-up of<br />

a test blanket module for ITER, presented at the Int. Workshop on Fast Neutron Detectors and Applications (Cape Town 2006)<br />

[A3.20] K. Seidel et al., Measurement and analysis of the neutron flux spectra in a neutronics mock up of the HCPB test blanket module,<br />

presented at the 24 th Symposium on Fusion Technology - SOFT-24 (Warsaw 2006), accepted for publication in Fusion Eng. Des.<br />

References<br />

51<br />

Progress Report 2006


A3 Technology Programme<br />

A Fusion Programme<br />

C/E<br />

Percent nuclide heat contribution<br />

1.3<br />

1.2<br />

1.1<br />

1.0<br />

0.9<br />

0.8<br />

0.7<br />

0.6<br />

C/E<br />

1.15<br />

1.05<br />

0.95<br />

0.85<br />

Beta heat<br />

C/E<br />

Error bars include only<br />

exp. uncertanties<br />

Error bars include only exp. uncertanties<br />

0.65 0.75<br />

10 2 10 4 10 6<br />

10 2<br />

10 4<br />

10 6<br />

0.5<br />

0.5<br />

Decay time (s)<br />

Decay time (s)<br />

10 2 10 3 10 4 10 5 10 6 10 2 10 3 10 4 10 5 10 6<br />

Decay time (s)<br />

Decay time (s)<br />

100<br />

10<br />

1<br />

Mo91<br />

Mo99<br />

Beta heat<br />

Nb98m<br />

Nb97<br />

Nb96<br />

Zr97<br />

Tc99m<br />

about 20%. The last results are consistent with the weak underestimation of the tritium breeding<br />

also found for the main block. According to these results, the shielding performance of the mockup<br />

is predicted within ±20% accuracy. The tritium production (most of which coming from 6 Li) is mainly<br />

sensitive to the 9 Be cross sections for elastic scattering and, to a lower extent, for the 9 Be (n,2n)<br />

reaction. The sensitivity/uncertainty analysis showed that the TPR from 6 Li changes by about 2%<br />

per % change of the 9 Be elastic scattering integral cross sections, but the sensitivity with respect to<br />

the angular differential cross section dσ/d Ω could be higher [A3.21, A3.22]. These results indicate<br />

that the angular differential cross section for 9Be elastic scattering may require further improvement.<br />

Results from the HCPB mockup experiment implied that for the HCPB TBM in ITER the tritium<br />

production is underestimated by the calculations based on the European Fusion File (EFF) and<br />

FENDL nuclear data (used in this analysis) by less than 10% on average, at the lower bound of the<br />

assessed uncertainty margin, and that the neutron and gamma ray shielding performance is<br />

predicted within ±20% accuracy [A3.23]. The pre-analysis of the next experiment on a mockup of<br />

the TBM HCLL has also been completed.<br />

Experimental validation of neutron cross sections for fusion-relevant materials<br />

1.1<br />

1.0<br />

0.9<br />

0.8<br />

0.7<br />

0.6<br />

Percent nuclide heat contribution<br />

C/E<br />

1.15<br />

1.05<br />

0.95<br />

0.85<br />

0.75<br />

Gamma heat<br />

Gamma heat<br />

Fig. A3.20 – Results from decay heat measurements for beta and gamma. Inserts: experimental<br />

uncertainties<br />

0.1<br />

10 2 10 3 10 4 10 5 10 6<br />

0.1<br />

10 2 10 3 10 4 10 5 10 6<br />

Decay time (s)<br />

Decay time (s)<br />

100<br />

10<br />

1<br />

Mo91<br />

Nb97<br />

Nb96<br />

Mo99<br />

Mo101<br />

Mo93m<br />

Fig. A3.21 – Beta and gamma heat nuclide contributions - 65 nm range<br />

Y89m<br />

Tc99m<br />

Nb92m<br />

Nb98m<br />

Zr89<br />

Nb95<br />

The neutron-induced decay heat on samples of molybdenum (99.99 %) irradiated at FNG in a firstwall-like<br />

neutron spectrum was measured (European Activation File [EAF] Project). Three<br />

molybdenum samples were irradiated for about 3.5 h at FNG. One sample was monitored with the<br />

<strong>ENEA</strong> decay heat measuring system where gamma and beta decay heats are simultaneously<br />

Progress Report 2006<br />

52


measured. The other two samples were monitored with HPGe detectors. The decay times studied went<br />

from a few minutes up to some days after irradiation. Comparison between experimental data and EASY<br />

predictions is satisfactory for both beta and gamma heat (fig. A3.20). A discrepancy (C/E=0.85±0.1 exp<br />

err.) found in the gamma heat for short decay times could be due to the reactions 92 Mo(n,2n) 91 Mo,<br />

92 Mo(n,2n) 91m Mo m (IT)→ 91 Mo, and/or to decay data of 91 Mo. This nuclide is responsible for about 90% of<br />

the heat produced for a short decay time (


A3 Technology Programme<br />

A3.8 IFMIF<br />

A Fusion Programme<br />

Remote handling of the back-plate bayonet concept – bolted solution<br />

The reference International Fusion Materials Irradiation Facility (IFMIF) target design is based on the<br />

concept of a replaceable back-plate. At present two different design options for the back-plate<br />

replacement are under investigation: the<br />

reference design system, i.e., the so-called cut<br />

and re-weld concept proposed by the Japanese<br />

IFMIF team, and the alternative solution<br />

developed in Europe and known as the backplate<br />

bayonet concept. The latter concept is<br />

based on the possibility of replacing the backplate<br />

while working laterally to the target, thus<br />

simplifying the sequence needed to perform the<br />

operations and, as already demonstrated,<br />

reducing back-plate-replacement operational<br />

time. In addition the bayonet concept has a<br />

major advantage in that the material for final<br />

disposal is reduced. Two prototypes of the backplate<br />

bayonet concept were manufactured in<br />

2002. The first prototype is provided with a<br />

Fig. A3.24 – IFMIF back-plate bayonet concept closing system based on a skate system and<br />

based on bolted closing system<br />

has already been successfully tested, whilst the<br />

second (fig. A3.24) is characterised by a closing<br />

system consisting of bolted closure. The<br />

experimental activities carried out on the second<br />

prototype were aimed at evaluating its suitability<br />

for remote handling (RH). Comparison of the two<br />

prototypes was performed from the RH<br />

viewpoint.<br />

Fig. A3.25 – New em pump for LIFUS III: a) initial<br />

phase of mounting; b) final phase<br />

In particular, the activities were articulated as<br />

follows: development of the installation and<br />

removal procedures; modification of the<br />

prototype; adaptation of the bolting tool, RH<br />

trials themselves; post-analysis of results. The<br />

RH activities for the target prototype were<br />

executed in the <strong>ENEA</strong> Brasimone divertor<br />

refurbishment platform (DRP) and were<br />

successfully completed in July 2006.<br />

Lithium corrosion and chemistry:<br />

LIFUS III facility<br />

In the framework of the key action phase of<br />

IFMIF development, the activities carried out<br />

during 2006 included corrosion/erosion testing<br />

of AISI 316 and EUROFER 97 in IFMIF<br />

representative conditions; experimental<br />

validation of the lithium purification strategy,<br />

based on a single cold trap and two hot traps<br />

having specific getters for nitrogen and<br />

hydrogen; functional validation of the<br />

Progress Report 2006<br />

54


performance of the resistivity-meter for lithium<br />

impurities, developed in collaboration with Nottingham<br />

University. These activities have to be performed in the<br />

LIFUS III loop, which will be the first liquid metal loop at<br />

Brasimone to have liquid lithium as process fluid. The<br />

whole loop was refurbished because the previously<br />

chosen canned pump failed continuously and had to<br />

be substituted with an em pump (fig. A3.25). Due to the<br />

strong reactivity of Li with damp air and water, stringent<br />

safety measures were carried out. In addition, new<br />

pipes were installed, the test section was modified to<br />

enhance the safe manipulation of the corrosion<br />

specimens, the gas purification was enhanced by<br />

interposition of a specific on-line getter, a glove box<br />

was installed, the data acquisition software was<br />

adapted, the experimental hall was refurbished to meet<br />

the safety requirements, and the personnel were trained to deal with lithium safety issues. Moreover the<br />

design calculations were revised to match new pump conditions. The complete thermo-mechanical<br />

verification of the piping was successfully performed by the ANSYS code. Similarity calculations were<br />

carried out to adapt the pump performance to the loop conditions in order to find a new reference<br />

hydraulic working point (fig. A3.26).<br />

Bar<br />

4<br />

3<br />

2<br />

1<br />

0<br />

Pump interdiction area<br />

Line of minimum<br />

velocity (10 m/s)<br />

open valve<br />

valve 67% open<br />

Calculated<br />

operational point<br />

-1<br />

0 10 20 30 40<br />

Liter/min<br />

valve 33% open<br />

V=300 V<br />

V=340 V<br />

V=380 V<br />

Fig. A3.26 – Re-calculated operational point<br />

Preliminary remote handling handbook for IFMIF facilities<br />

A preliminary remote handling handbook (PRHH) is to be produced for the target and test facilities. It is<br />

based on the work already done and on the documentation available. So far, apart from the introduction<br />

giving a description of IFMIF together with the methodologies adopted, the work has been focussed on 1)<br />

defining a set of rules to distinguish components requiring RH maintenance from those that can be<br />

maintained hands on; 2) identifying components requiring RH maintenance (not completed); 3) developing<br />

RH procedures for each component; 4) evaluating the area accessibility and interference with other<br />

components and 5) defining the technical requirements for the devices and equipment to be used for the<br />

RH operations. The following components and devices have already been studied in the target and in the<br />

test facilities:<br />

1. Target assembly and replaceable back wall: both concepts (cut & reweld option and bayonet option)<br />

were studied and compared. The procedures for back-wall replacement were already known as well as<br />

the equipment and devices to perform these operations. A preliminary study for the feasibility of backwall<br />

replacement through a lateral window was also performed and will be included in the PRHH.<br />

2. Replacement of the quench tank and other components from the target area.<br />

3. Main Li loop components have been and, still are, under investigation.<br />

4. Requirements for the main devices and tools have been defined: robotic arm and bolting tool for the<br />

bayonet concept; common manipulator system (CMS); transporter for the target assembly system. (No<br />

data are available for the YAG machine).<br />

5. The general layout of the access cell of the test facility has been defined. (The path for the cooling<br />

systems is still missing).<br />

6. The general procedures for the vertical test assembly (VTA) replacement from the test cell, including<br />

separation and transportation of the test modules in the test module handling cell, have been<br />

completed.<br />

7. Requirements for the main devices to be installed in the access cell have been defined: the Universal<br />

Robot System (gantry crane), the support for the removal of the test modules and the transporter of the<br />

test modules from the access cell to test module handling cell.<br />

The work is expected to be completed by the end of June 2007.<br />

55<br />

Progress Report 2006


A3 Technology Programme<br />

Inventories and dose rates induced by deuterons and neutrons in the<br />

accelerator system<br />

A Fusion Programme<br />

ANITA-DEUT is the newly developed deuteron activation code package dealing with deuteroninduced<br />

transmutation and activation. The code can work with two deuteron cross-section libraries:<br />

the first based on the ACSELAM library; the second, on the file EAF_D_GXS-2005.1 of the EASY-<br />

2005-1 system. A methodology approach was set up to calculate deuteron/neutron-induced decay<br />

gamma sources and evaluate dose rates along the accelerator line because of deuteron beam<br />

losses. The first step in the sequence consists of deuteron and secondary-neutron transport<br />

calculations via the MCNPX code (version 2.5b). The deuteron and neutron spectra obtained are<br />

used in ANITA-DEUT and ANITA-IEAF activation codes to calculate the radioactive inventories of<br />

materials and the corresponding decay gamma sources, which are then used for gamma transport<br />

calculations via the VIT<strong>ENEA</strong>-IEF/SCAL<strong>ENEA</strong>-1 and MCNP-4C2 code systems to obtain the beamoff<br />

dose rates around the various parts of the IFMIF accelerator (i.e., radiofrequency quadrupole<br />

(RFQ) and drift tube linac (DTL). The decay gamma dose rates do not represent a hazard source for<br />

workers (maximum value 5.6×10 -2 μSv/h on the surface of the RFQ section 10) [A3.24]. Preliminary<br />

calculations were performed for the last tank of the DTL with source deuterons of 40 MeV,<br />

considering a deuteron current loss of 130nA (8.11×10 11 d/s). On the basis of this value, the beamoff<br />

total dose rate around the DTL is less than 10 μSv/h at 1 day’s cooling time.<br />

Inventories and dose rates induced by deuterons and neutrons in the cooling<br />

system<br />

The structural materials of the high-energy beam transport (HEBT) section can be activated by<br />

deuterons due to beam losses, by secondary neutrons produced by deuteron-induced nuclear<br />

reactions and by back-stream neutrons coming from the lithium target. The deuteron source energy<br />

is 40 MeV. HEBT activation due to neutrons was evaluated through the MCNP-4C2 code with the<br />

McEnea neutron source, which is based on the measurements of neutron emission spectra<br />

produced in Li(d,n) reactions for Ed=40 MeV performed at the Cyclotron and Radioisotope Center<br />

(CYRIC), Tohoku University, Japan. Preliminary calculations were performed, considering a deuteron<br />

beam-loss current of 865nA (5.4×10 -2 d/s). With this value the most relevant contribution to decay<br />

gamma dose rates in the area around the HEBT is due to the activation induced by lost deuterons<br />

(about 70%). The dose rate contribution of back neutrons is higher than that caused by secondary<br />

neutrons due to beam losses.<br />

A3.9 Safety and Environment, Power Plant Studies and<br />

Socioeconomics<br />

Failure mode and effect analysis for the European test blanket modules<br />

A failure mode and effect analysis (FMEA) was done to study possible safety-relevant implications<br />

arising from failures in the HCPB [A3.25] and HCLL [A3.26] TBMs for ITER. For both modules, six<br />

postulated initiating events (PIEs) were selected for deterministic assessments:<br />

• FB1 (loss of flow in a TBM cooling circuit because of circulator/pump seizure).<br />

• LBB1 (loss of TBM cooling circuit inside breeder blanket box: rupture of a sealing weld).<br />

• LBO3 (loss of coolant outside vacuum vessel because of rupture of tubes in a primary TBM-HCS HX).<br />

• LBP1 (loss of coolant outside vacuum vessel because of rupture of a TBM cooling circuit pipe<br />

inside port cell).<br />

• LBV1 (loss of TBM cooling circuit inside vacuum vessel: rupture of TBM-FSW),<br />

• TBP2 (small rupture from "TBM - tritium extraction system" process line inside port cell).<br />

Progress Report 2006<br />

56


Failure mode and effect analysis for remote handling transfer systems of ITER<br />

A FMEA at component level was done to study possible failures while performing remote handling (RH)<br />

operations [A3.27]. Two safety-relevant PIEs were selected: 1) break in “vacuum vessel + cask” isolating<br />

boundary during RH operations, inducing release of radioactive products (fraction of dust and T implanted<br />

in vessel) into the port cell; 2) cask stop and leakage during RH transportation of divertor cassette to hot<br />

cell, inducing release of radioactive products (fraction of dust and T implanted in transported components)<br />

into the gallery. Deterministic analysis could be required to evaluate the response of the safety systems<br />

(e.g., efficiency of ventilation systems, isolation of heating, ventilation and air conditioning [HVAC] system)<br />

and effectiveness of rescue operations in mitigating the consequences and risks for workers. Compliance<br />

of the design features with the safety limits in the case of a fire triggered on board the transporter should<br />

be required. Some concerns on recovery scenarios should dust or tritium be released inside the port cell<br />

or gallery could arise from the use of the air cushion transportation system. Accident rescue scenarios were<br />

also identified by the FMEA and grouped in seven families.<br />

Validation of computer codes and models<br />

New contributions were obtained for validation of the activation code package ANITA-2000 against the<br />

Karlsruhe Isochronous Cyclotron (KIZ) and <strong>ENEA</strong> FNG experiments [A3.28, A3.29]. In the KIZ experiments<br />

a saturation thick beryllium target was irradiated by 19-MeV deuterons. Samples of vanadium alloys, nickel,<br />

copper, lithium orthosilicate, EUROFER 97 and tungsten were irradiated. Specific activities in Bq/kg for<br />

each sample material for several gamma ray emitting activation products were obtained and compared<br />

with the calculation. ANITA-2000 handled satisfactorily the activation channels induced by neutrons with a<br />

smooth continuum spectrum. The discrepancies between calculated and experimental (C/E) activity values<br />

are in the range 10-20%. The results of irradiation of samples of molybdenum and tantalum at the 14-MeV<br />

FNG neutron source were also compared with ANITA predictions. For molybdenum the agreement<br />

between C/E beta decay heats is good (within 10%) for all cooling times, while it is within 15% for the<br />

gamma decay heats; for tantalum the agreement is very good (within 2%) for all cooling times for the beta<br />

decay heat and lower than 10% for the gamma decay heat.<br />

Time factors to be used for the JET shutdown dose-rate evaluation [A3.30, A3.31] in the direct one-step<br />

(D1S) method were obtained with the ANITA-2000 code (FENDL/A-2.0 activation data library). The ANITA-<br />

2000 calculations were performed using the data related to a) the JET materials composition for the<br />

detector positions D1 (irradiation end) and D2 (Geiger Müller tube); b) the irradiation scenarios (DD and DT);<br />

[A3.24] D.G. Cepraga, M. Frisoni and G. Cambi, Evaluation of activation inventories and dose rates induced by deuterons in the IFMIF<br />

accelerator system, <strong>ENEA</strong> Internal Report FUS-TN-SA-SE-R-146 (2006)<br />

[A3.25] T. Pinna, Failure mode and effect analysis for the European Helium Cooled Pebble Bed (HCPB) test blanket module, <strong>ENEA</strong> Internal<br />

Report FUS-TN SA-SE-R-152 (2006)<br />

[A3.26] T. Pinna, Failure mode and effect analysis for the European Helium Cooled Lithium Lead (HCLL) test blanket module, <strong>ENEA</strong> Internal<br />

Report FUS-TN SA-SE-R-155 (2006)<br />

[A3.27] R. Caporali and T. Pinna, Failure mode and effect analysis for remote handling transfer systems of ITER FEAT, <strong>ENEA</strong> Internal Report FUS-<br />

TN SA-SE-R-156 (2006)<br />

[A3.28] V. Massaut et al., Validation of European computer codes used for fusion safety analysis, presented at the 8 th IAEA Technical Meeting<br />

on Fusion Power Plant Safety (Wien 2006)<br />

[A3.29] D.G. Cepraga, G. Cambi and M. Frisoni, ANITA-2000 activation code packages: 2005 validation effort against Karlsruhe Isocyclotron and<br />

FNG-<strong>ENEA</strong> experiments, <strong>ENEA</strong> Internal Report FUS-TN-SA-SE-R-136 Rev.1 (2006)<br />

[A3.30] L. Petrizzi et al., Benchmarking of Monte Carlo based shutdown dose rate calculations applied in fusion technology: from the past<br />

experience a future proposal for JET 2005 operation, Fusion Eng. Des. 81, 1417-1423 (2006)<br />

[A3.31] M. Angelone et al., Neutronics experiment for the validation of activation properties of DEMO materials using real DT neutron spectrum<br />

at JET, Fusion Eng. Des. 81, 1485-1490 (2006)<br />

References<br />

57<br />

Progress Report 2006


A3 Technology Programme<br />

A Fusion Programme<br />

%<br />

%<br />

c) the relevant isotopes considered for the shutdown dose rates at the selected JET D1 and D2<br />

positions [A3.32]. A first analysis was performed by considering the JET irradiation scenario (DD and<br />

DT) up to March 2004. The gamma material decay sources were obtained (1.5 y cooling time) and<br />

used in SCAL<strong>ENEA</strong>-1 to get the shutdown dose rate (September 2005, measurement time) in the<br />

D1 position. The C/E ratio obtained is 1.015.<br />

Finally, updated analyses were carried out on the possibility of clearance of the ITER vacuum vessel<br />

materials, considering the new (August 2004) unconditional clearance levels given in the IAEA Safety<br />

Guide RS-G-1.7. The relevant results from the updated analysis [A3.33] are:<br />

• The 430 ferritic steel and the SS 304B4 steel of the outboard vacuum vessel zone (VVSHDO) are<br />

clearable after a longer time compared with the previous analysis results when the TECDOC-855<br />

clearance level data were employed. This is particularly true for the SS 304B4 steel, which<br />

becomes clearable only after about 6000 years (with respect to the 90 years of the previous<br />

analysis).<br />

• The remarkable change for the VVSHDO(2) – SS 304B4 steel is due to the highest contribution<br />

(at 100 years’ cooling time) from the Ni-63, which is now (i.e., with the RS-G-1.7) about 40%<br />

compared to the older (i.e., with the TECDOC-855) value of about 10%.<br />

Dust removal experiments in STARDUST<br />

Dust removal inside the plasma chamber is a concern with regard to machine performance and to<br />

safety. Experiments were carried out in the <strong>ENEA</strong> STARDUST facility in 2005 [A3.34] by using a<br />

stream of air in the volume representing the vacuum vessel in which characterised carbon, tungsten<br />

and stainless-steel dusts were placed. The capacity of dust mobilisation by means of the air inflow<br />

was between a few percent and 100%, depending mainly on the type of dust and on the kind of<br />

150<br />

125 T=20°C<br />

150<br />

75<br />

50<br />

25<br />

0<br />

1234 5678 9101112<br />

35<br />

30<br />

25<br />

20<br />

15<br />

10<br />

5<br />

0<br />

T=50°C<br />

1234 5678 9101112<br />

N. test<br />

%<br />

%<br />

8<br />

6<br />

4<br />

2<br />

0<br />

T=20°C<br />

1 2 3 4 5 6 7 8 9 101112<br />

T=50°C<br />

0<br />

1234 5678 9101112<br />

N. test<br />

Fig. A3.27 – Mobilisation factor and capture factor for carbon dust in hot and<br />

cold conditions (red 10 m, blue 30 m, yellow 1 h<br />

8<br />

6<br />

4<br />

2<br />

deposition (heap or flat<br />

layer). Mobilisation is more<br />

effective in cold conditions.<br />

The efficiency of the system<br />

to capture dust on the filter<br />

reached a maximum of<br />

about 7.5% for carbon in the<br />

geometrical configuration of<br />

the STARDUST facility.<br />

Heavy dusts such as SS316<br />

and W did not reach the filter.<br />

Figure A3.27 shows the<br />

carbon dust results. The<br />

tested technique of removing<br />

the vacuum vessel dust has<br />

low efficiency in the<br />

collection of powder<br />

removed from the vessel and<br />

deposited on appropriate<br />

surfaces (i.e., filters). The use<br />

of an air stream directly on the dust deposit can improve the effectiveness of the removal but, to<br />

collect a significant amount of dust in the filter, the pressure in the volume must be increased, so<br />

that conditions which are dangerous for the internal equipment can be avoided.<br />

Feasibility study of a torus-shaped facility for dust mobilisation studies<br />

A feasibility study was carried out for a toroidally shaped facility for dust mobilisation and removal<br />

experiments [A3.35]. The facility, named STARDUST-U (fig. A3.28), should facilitate the extrapolation<br />

Progress Report 2006<br />

58


Fig. A3.28 – View of the upper part of STARDUST-U<br />

to ITER of the experimental results obtained during<br />

tests in which dusts are mobilised. It allows the<br />

monitoring, by laser diagnostics, of the dust<br />

concentration evolution in the different zones of the<br />

machine. The windows will make it possible to view<br />

the dust mobilisation in the zone with laser systems if<br />

the concentration is below 1000 particles/cm 3 .<br />

Although this concentration can be far from<br />

accidental conditions in the ITER device, the<br />

dynamics of the phenomena during mobilisation can be helpful in extrapolating the results at higher<br />

concentrations, mainly to test the performance of the dust simulation codes.<br />

The estimated cost of the whole facility is about 16,600 Euros (2006 evaluation).<br />

Post-accident occupational exposure and radioprotection<br />

The objective of this study [A3.36] was to provide an indication of occupational radiation exposure (ORE)<br />

consequences associated with post-accident recovery operations. The accident analysis results<br />

documented in Volume VII of the ITER Generic-Site Specific Safety Report (GSSR) were used. The focus<br />

was on the actions that are needed to restore the machine to the operational state, and on the potential<br />

impact of the actions on the collective worker dose. Even the release of one gram of tritium (in the form of<br />

HTO), one gram of activated corrosion products, or one gram of tokamak dust can cause significant<br />

contamination concerns. Airborne contamination is not a significant problem, as this can be easily removed<br />

by the building/room ventilation system working in conjunction with the re-circulating detritiation system<br />

and exhaust detritiation system. Surface tritium contamination is a bigger concern, as this takes<br />

considerably more time to reduce, to acceptable levels, using the same systems. Surface aerosols from<br />

activated corrosion products (ACPs) and dust contamination could be an even bigger concern if water<br />

sprays are either not available, or not effective, for washing the deposited aerosols and dust in the active<br />

drain system.<br />

Integration of design modifications (in Rapport Préliminaire de Sûreté) to tritium<br />

building and detritiation system<br />

The tritium confinement strategy of the ITER design was compared with the safety requirements and the<br />

safety standards and guidelines (ISO 17873) related to nonreactor nuclear facilities to find possible critical<br />

issues in the design of tritium confinement [A3.37]. According to ISO 17873 the tritium plant has only two<br />

confinement barriers, whilst the actual safety reports on the ITER tritium buildings claim that three lines of<br />

defence are available. According to ISO standards the process equipment and related containment<br />

[A3.32] M. Frisoni et al., ANITA 2000 activation code package calculation in support of the <strong>ENEA</strong> Direct 1-Step D1S method, <strong>ENEA</strong> Internal<br />

Report FUS-TN-SA-SE-R-150 (2006)<br />

[A3.33] G. Cambi, D.G. Cepraga and M. Frisoni, Summary results of 2005 activation calculation in support of ITER, <strong>ENEA</strong> Internal Report FUS-<br />

TN-SA-SE-R-135 (2006)<br />

[A3.34] M.T. Porfiri, S. Paci and N. Forgione, Experimental campaign 2005 for the dust removal in the STARDUST facility, <strong>ENEA</strong> Internal Report<br />

FUS-TN-SA-SE-R-145 (2006)<br />

[A3.35] M.T. Porfiri et al., Feasibility study for a torus shape facility aimed at dust mobilization and removal experiments, <strong>ENEA</strong> Internal report<br />

FUS-TN-SA-SE-R-158 (2006)<br />

[A3.36] A. Natalizio, L. Di Pace and T. Pinna, Post-accident recovery: a worker dose perspective, <strong>ENEA</strong> Internal Report FUS-TN SA-SE-R-149<br />

(2006)<br />

[A3.37] C. Rizzello and L. Di Pace, Tritium building and detritiation systems. Considerations on tritium confinement, <strong>ENEA</strong> Internal Report FUS-<br />

TN-SA-SE-R-148 (2006)<br />

References<br />

59<br />

Progress Report 2006


A3 Technology Programme<br />

A Fusion Programme<br />

enclosure form the first containment barrier, while according to ITER the process equipment<br />

constitutes the first barrier and, in the specific case, glove boxes are part of the second barrier. The<br />

ventilation flow rates chosen appear too low compared to ISO Standards and also to other related<br />

guidelines (e.g., US Department of Energy standards).<br />

An alternate concept of the ITER atmosphere detritiation has been proposed to mitigate accidental<br />

tritium releases [A3.38]: a scrubber capable of contacting with a spray of water all the air effluent<br />

from the areas where the tritium systems are located. If a tritium spill occurs in the room atmosphere,<br />

the stream of scrubbing water will dilute the concentration of HTO in the effluent, thus reducing the<br />

related environmental impact. A critical analysis of this unit is however required to demonstrate the<br />

capability of such a concept to cope with the ITER safety requirements.<br />

Collection and assessment of data related to JET occupational radiation<br />

exposure<br />

The scope of the work [A3.39] was to update the database of JET ORE experience up to the end<br />

of 2005. The collective worker doses are the highest during the machine shutdown state, but are<br />

due primarily to in-vessel work. The monthly collective worker doses accrued from ex-vessel work<br />

during the shutdown state are comparable to those accrued during the non-shutdown state. The<br />

maintenance group collective doses are the highest during the machine shutdown state, but are due<br />

primarily to in-vessel work. The maintenance group monthly collective doses accrued from ex-vessel<br />

work during the shutdown state are comparable to those accrued during the non-shutdown state.<br />

The majority of the collective doses from ex-vessel work, with the machine in the shutdown or nonshutdown<br />

state, is accrued by non-maintenance workers. Finally, there is no significant difference<br />

for ex-vessel exposure time between the shutdown and non-shutdown state. The same is true for<br />

work effort. It is possible to conclude that most of these results could be generally applicable to<br />

ITER. In fact the ITER doses accrued during the non-shutdown state could be expected to be a<br />

significant fraction of the total dose, as they are at the JET facility.<br />

JET data collection on malfunctions and failures of ICRH system components<br />

The data from operating experience of JET for the ion cyclotron resonance heating (ICRH) system<br />

were gathered for the data collection on failures of components used in fusion facilities [A3.40].<br />

Alarms/failures and malfunctions occurred during operations from March 1996 to November 2005.<br />

Data related to crowbar events were also collected. About 3400 events classified as alarms or<br />

failures related to specific components or sub-systems were identified. The ICRH was operated<br />

during about 12000 plasma pulses from March 1996 to November 2005. Failure probabilities on<br />

demand were evaluated with regard to the number of pulses operated. The highest number of<br />

alarms/failures (1243) are related to erratic/no-output of the instrumentation and control (I&C)<br />

apparatus. Tetrode circuits failed 829 times, the high-voltage power supply system 466 times and<br />

the tuning elements 428 times. The maximum number of events related to I&C (595) led to<br />

anomalous operations of CODAS, followed by 125 anomalous operations of stubs. The number of<br />

failures/alarms of the ICRH system increases quite linearly with the number of pulses in which the<br />

system is operated. A crowbar event happened on average every nine ICRH pulses. The rate of<br />

failure on demand of an ICRH module is about 0.29/pulse.<br />

JET dust in-vitro experiment: result assessment and in-vivo experiment<br />

literature review<br />

The work dealt with the analysis of in-vivo experiments and dosimetry models on the inhalation of<br />

tritiated dust [A3.41]. The most consistent in-vivo experimental activity on the inhalation of metal<br />

tritides was performed at the Lovelace Respiratory Research Institute (Albuquerque, NM, USA),<br />

using Ti, Hf and Zr tritides with different size distributions. The aim of these experiments was to set<br />

up a biokinetic and dosimetry model to better describe inhalation of T particles in a living being, and<br />

Progress Report 2006<br />

60


to derive suitable dose conversion factors. Analysis of the experimental results confirmed the concerns<br />

about the inadequacy of the protection guidelines for workers exposed to tritium in particulate form (dusts,<br />

flakes), if based on the radiotoxicity of tritium. The behaviour of tritiated dust in the human body is still not<br />

well understood, considering the different size distributions and the variety of base materials (through<br />

density and morphology). The in-vivo and in-vitro studies on tritiated dust have shown the dependence of<br />

the tritium clearance and retention in the human body on their physico-chemical parameters. Tritium<br />

absorption in the lungs from tritiated dust ranges from absorption type S (slow) to type M (moderate)<br />

according to the International Commission on Radiological Protection (ICRP) classification, whereas HTO<br />

and HT are classified as F (fast).<br />

Study on recycling of fusion activated material<br />

The study was devoted to the Power Plant Conceptual Study (PPCS) Model AB, based on the HCLL<br />

breeder blanket concept using EUROFER as structural material and Pb-17Li as breeder material, neutron<br />

multiplier and tritium carrier [A3.42]. For each main component the categorisation for two decay times (50<br />

and 100 years) has been provided according to the following classification:<br />

• Clearable, with clearance index CI < 1 (CI from IAEA-TECDOC-855).<br />

• Specific activity SH”).<br />

Comparing the categorisation results, given in terms of mass or volumes, there is a large increase in the<br />

fraction that could be cleared and recycled without major complications, allowing 100 years of decay.<br />

Passing from 50 to 100 years, there is a large transfer of material (~60% of the total mass) from class<br />

“>SH” to class “SH”. This suggests that it would be convenient to extend the decay period up to 100<br />

years. Furthermore, the extra decay period up to 100 years could be limited to SH and >SH categories,<br />

as the overall inventory of clearable plus material with specific activity SH inventory of 65% in mass at 100<br />

years of decay. Considering all the activated materials generated from<br />

decommissioning and from operation, a conservative approach for their<br />

management, based on clearance/recycling of lifetime components only,<br />

Clearable<br />

< 1000 Bq/g<br />

SH<br />

>SH<br />

43.0%<br />

32.8%<br />

5.0%<br />

19.2%<br />

66.4%<br />

9.4%<br />

24.2%<br />

0.0%<br />

would lead to 29% mass cleared/recycled and the rest (71%) disposed of. If one takes into account the<br />

scenario with LiPb reuse, and an effective recycling capability of ~50% of >SH and SH categories, the<br />

cleared/recycled mass fraction would be ~69%, while the remainder should be disposed of.<br />

[A3.38] C. Rizzello and L. Di Pace, Proposal of an atmosphere detritiation system for the ITER plant, <strong>ENEA</strong> Internal Report FUS-TN-SA-SE-R-<br />

151 (2006)<br />

[A3.39] A. Natalizio and M.T. Porfiri, JET radiation exposure analysis. Data relating to the years 1988-2005, <strong>ENEA</strong> Internal Report FUS-TN-SA-<br />

SE-R-157 (2006)<br />

[A3.40] G. Cambi and T. Pinna, JET data collection on component malfunctions and failures of ion cyclotron resonant heating ICRH system,<br />

<strong>ENEA</strong> Internal Report FUS-TN SA-SE-R-143 (2006)<br />

[A3.41] L. Di Pace, Literature study on in vivo experiments with tritiated dust, <strong>ENEA</strong> Internal Report FUS-TN-SA-SE-R-144 (2006)<br />

[A3.42] L. Di Pace, Definition of components and materials involved in clearance and recycling for PPCS plant model AB, <strong>ENEA</strong> Internal Report<br />

FUS-TN-SA-SE-R-153, TW5-TSW-001/<strong>ENEA</strong>/D1 (Rev. 1) (2006)<br />

References<br />

61<br />

Progress Report 2006


A4 Superconductivity<br />

A Fusion Programme<br />

In 2006 activities were focussed basically on the ITER project and related tasks, as well as on some<br />

important non-ITER tasks. In particular, work began on an important goal of the ITER parallel programme,<br />

the so-called Broader Approach (BA), consisting of the design and construction of the NbTi toroidal field<br />

coils of the new Japanese tokamak JT-60SA. Due to the complexity of the subject, the work is carried out<br />

in close collaboration with other <strong>ENEA</strong> groups, and within an international framework including the French<br />

and, of course, Japanese teams.<br />

In the framework of an EFDA assignment, <strong>ENEA</strong> has been charged with following the construction of the<br />

new European dipole conductor, a new test facility for ITER full-size samples. In this framework, the group<br />

developed and patented a new type of joint between superconductive cables. <strong>ENEA</strong> is also in charge of<br />

surveying the manufacturing of the new conductor samples for the toroidal field coils of ITER.<br />

The activity related to high-temperature superconductors (HTSs) can be summarised as follows: 1) Metallic<br />

textured substrate for YBe 2 Cu 3 O 7-x -coated conductors: texture and micro-structural evolution and control<br />

of in Ni-5at.% W alloy and development of copper-based substrates, carried out in collaboration with the<br />

Technical University of Cluj-Napoca (TUCN) Romania. 2) Chemical approach for YBCO film deposition by<br />

the MOD-TFA technique and introduction of artificial pinning centres in YBCO films for critical current<br />

improvement (in collaboration with TUCN and Roma Tre University). 3) Activities carried out in the framework<br />

of the Frascati Laboratory of the National Institute of Physics (LNF-INFN) superconducting magnet<br />

programs: i) magnetic characterisation of NbTi and Nb 3 Sn wires for the development of fast ramped<br />

superconducting dipoles for the FAIR accelerators at Gesellschaft fu .. r Schwerionenforschung (GSI)<br />

Darmstadt Germany, NTA_DISCORAP programme; ii) application of MgB 2 wires and tapes, MARIMBO<br />

experiment. 4) Transport and thermal stability characterisation of commercially available HTS wires and<br />

tapes, funded by the EFDA Technology Work Programme HTSPER task, carried out with the support of the<br />

SuperMat National Research Council (CNR)-INFM Regional Laboratory facilities at Salerno Italy.<br />

All these activities are leading <strong>ENEA</strong> toward deeper knowledge of superconducting-based magnet<br />

technology.<br />

A4.2 ITER and ITER-Related Activities<br />

ITER toroidal field cable conductor<br />

<strong>ENEA</strong> is a member of the international testing group for the ITER magnet R&D. At the end of 2005<br />

the measurement campaigns started on the samples (toroidal field advanced strands [TFAS] 1<br />

and 2), the first ITER-type full-size TF conductors, made with the recently developed “advanced”<br />

Nb 3 Sn strands [A4.1, A4.2].<br />

<strong>ENEA</strong> actively contributed to the definition of the testing programme for the conductors, attended<br />

Progress Report 2006<br />

62


the tests, which continued through the first half of 2006, and participated in the data analysis and<br />

processing, in collaboration with the international testing group members.<br />

In spite of the high-performance strands used in the cabling, the TFAS samples showed very unusual<br />

behaviour, with very wide transitions and well before the expected current sharing temperature values.<br />

Based on these results, EFDA promoted the fabrication of different toroidal field conductor prototypes<br />

(TFPRO project) for testing the effect of mechanical stress on the Nb 3 Sn superconducting characteristics.<br />

A total of four different cables was produced in 2006.<br />

<strong>ENEA</strong> was assigned the task to supervise the Luvata (formerly OuktoKumpu) activities for conductor<br />

manufacturing, under two different contracts (tasks TMSC-TFPRO-1298 and TMSC-LPTCON-<br />

1525).signed with EFDA.<br />

For the TFPRO task, two conductors were made with a bronze route Nb 3 Sn strand produced by EAS<br />

Germany, while for the LPTCON task a second couple used a strand produced by Oxford Instruments<br />

Superconducting Technologies (OST, England) with internal-tin technology (fig. A4.1).<br />

Differently from the previous TF geometry, the four samples have mainly the same cable layout, based on<br />

a starting triplet formed of two superconducting strands and one copper strand, but differing slightly in<br />

twist pitch length and final cable diameter (i.e., different void fraction). This choice was made in order to<br />

test the conductors under different mechanical stress conditions, to which the single strand is subjected<br />

to at operating conditions. The four conductor samples were shipped to the Association Euratom-Swiss<br />

Confederation Villigen [CRPP]) in November 2006 and are under test.<br />

<strong>ENEA</strong> is also working on developing the functional dependence of cable stiffness as a function of<br />

manufacturing parameters for the TF, through the use of computer codes based on finite elements models<br />

(FEMs) and artificial neural networks (task TMSC-CABLST).<br />

Fig. A4.1 – Cross section of the four cables ready for characterisation<br />

[A4.1] P. Bruzzone et al., Test results of two ITER TF conductor short samples using high current density Nb 3 Sn strands, presented at the<br />

Applied Superconductivity Conference - ASC (Seattle 2006)<br />

[A4.2] R. Zanino et al., IEEE Trans. Appl. Supercond. 16-2, 886 (2006)<br />

References<br />

63<br />

Progress Report 2006


A4 Superconductivity<br />

Current redistribution study on ITER conductors<br />

A Fusion Programme<br />

Cable-in-conduit conductor (CICC) performance is affected by the current distribution among the<br />

strands. To better understand this phenomenon and its implications, the results from the<br />

experimental data taken on the NbTi BB-III sample, tested in the TOSKA facility at FZK, and on the<br />

poloidal field insert sample tested in SULTAN (CRPP) in 2004 are being studied in collaboration with<br />

the University of Udine [A4.3].<br />

It has been shown that, during T cs measurements, a current re-distribution among the cable substage<br />

bundles appears just before the conductor transition, i.e., well before any detectable voltage<br />

development. Such a phenomenon, repeatable and depending on the overall transport current, has<br />

been observed by Hall probe sets designed with ad-hoc sensitivity and geometry, to allow also the<br />

reconstruction of the current distribution inside the CICC by means of the THELMA code.<br />

EFDA dipole<br />

As is well known, to reach the high field values requested for ITER operation, Nb 3 Sn<br />

superconducting cables have to be used to wind the main magnets, the central solenoid and the<br />

toroidal field coils. A fundamental step in the design and construction of these ITER magnets is to<br />

test a lot of conductor samples in relevant operating conditions. The only facility available at the<br />

moment in Europe for this purpose is SULTAN, which will not be able to withstand the huge duty<br />

foreseen for ITER construction in the very near future. Thus the European Community decided to<br />

build a new facility to share the test tasks with SULTAN.<br />

The facility will be based on a wind and react (W&R) dipole magnet wound from the last generation<br />

of Nb 3 Sn strands, the so-called “advanced strands”, and it will be the very first magnet based on<br />

such strands, and also the first dipole ever made by using CICC. <strong>ENEA</strong> has been charged with<br />

supplying the cable and following the manufacture of the entire amount of CICC for the dipole (task<br />

TMSC-DIPCON-1316). A few meters of a prototype conductor were manufactured and tested<br />

successfully in SULTAN in 2005. Unlike what was obtained in the first ITER TF full-size samples<br />

made using the same kind of strands (TFAS samples), the performance of the conductors agrees<br />

very well with expectations.<br />

The activity in 2006 was carried out in close collaboration with EFDA and Luvata. During this period<br />

the cable parameters were drawn, and a short dummy cable, made only of copper strands, was<br />

produced in order to define the cabling process and allow Luvata to prepare the environment and<br />

build the tools. The dummy consists of a short (50 m) copper cable, processed according to the<br />

actual cable parameters, jacketed and compacted to the final dimensions. It was decided together<br />

with EFDA to use a square cross section for this dummy cable, instead of the rectangular one used<br />

in 2005.<br />

A whole set of jacketed superconducting cables has been produced so far: two high-field units and<br />

four low-field units, for a total length of about 600 m. Of the six cable lengths, the low-field units are<br />

still uncompacted, while the two high-field units were compacted to the final dimensions and<br />

delivered to BNG Industries Germany for further assembling tests.<br />

Short lengths of each sample were prepared and sent to CRPP for characterisation. The results<br />

obtained so far for square conductors are not encouraging, probably due to the different void<br />

fraction and pressure on single strands during operation, so new rectangular cable samples are in<br />

preparation (fig. A4.2), and additional tests are foreseen (task PITCON).<br />

In the framework of the dipole design and construction, EFDA asked <strong>ENEA</strong> to develop a new type<br />

of joint between CICCs. <strong>ENEA</strong> developed a new joint concept and designed and fabricated some<br />

prototypes, whose test results showed a very low electrical resistance (< 1nΩ). The main<br />

advantages of this new joint (<strong>ENEA</strong> patent) are the low room occupancy (only slightly higher than<br />

the conductor size itself), the easy manufacturing procedure, and the low cost of realisation. The<br />

Progress Report 2006<br />

64


Fig. A4.2 – A short piece of the rectangular Nb 3 Sn<br />

CICC for dipole application<br />

<strong>ENEA</strong> joint was accepted by EFDA and used as the only type of<br />

joint between all the different lengths of the dipole magnet.<br />

Accompanying activities included providing mechanical analyses<br />

that will support the engineering design and manufacturing phase of<br />

the dipole procurement (contract TMS-EDDES4–1303, completed<br />

in 2006). The cable jacket main deformation occurring during the compaction and winding phase, the peak<br />

stress in the insulation, due to the large pressure excursion occurring during the magnet quench inside the<br />

conduit, and the thermo-mechanical analysis of dipole assembly during the cool-down phase were all<br />

evaluated. An experimental benchmark at the bending FEM analysis was also carried out. In the last part of<br />

2006 <strong>ENEA</strong> undertook (contract TMSC-DICOMO-1480) to develop a code model that could help to investigate<br />

the sensitivity of Nb 3 Sn superconducting properties to mechanical strain, which causes significant problems in<br />

the accurate performance prediction of large multi-strand CICC. Empirical relationships between strain and<br />

critical current have already been established, based on experimental measurements with known applied strain<br />

fields. The problems arise in the prediction of the strands stress/strain state within a cable. A large CICC<br />

includes hundreds of strands twisted with different pitches and in contact with each other and with the external<br />

jacket. Moreover, individual strands exhibit non-linear average mechanical behaviour due to the plasticity of the<br />

constituting components. At this point, the definition of a suitable numerical model for the mechanical analysis<br />

of strands in cables is still an open problem. Simplified methodologies should be developed with the aim of<br />

predicting the mechanical behaviour of cables and strands. The present activity deals with evaluating the strain<br />

state of the strands in the dipole CICC during energization within a magnetic field.<br />

In addition, EFDA charged <strong>ENEA</strong> with performing code simulations of the mechanical stress arising in the<br />

dipole structure during cool down and in operating conditions. This work was successfully carried out, with<br />

the help of L.T. Calcoli personnel, during the first half of 2006.<br />

Barrel bending experiments<br />

The EFDA task named “barrel bending experiments” (BARBEN) was completed during the first months of<br />

2006. Its aim was to study the effect of a bending strain applied on relatively long lengths of Nb 3 Sn<br />

“advanced strands”, initially inserted and compacted in stainless tubes before heat treatment.<br />

The effect of a 0.5% peak bending strain on the performance of an internal tin strand developed by OST<br />

for ITER was investigated. Comparison between the measured critical current data of the unbent samples<br />

and the results computed by Durham’s scaling law showed that, for the analysed system, the differential<br />

thermal contraction of stainless steel and superconducting strand corresponds to a –0.57%<br />

pre–compression of Nb 3 Sn at 4.2 K. At 12 T the strand shows a performance decrease of about 10-20%<br />

with the application of a 0.5% peak bending strain [A4.4].<br />

A further activity outside the EFDA task itself concerned clarifying the influence of the twist pitch length on<br />

the strand performance degradation, when submitted to bending strain. Hence similar experiments were<br />

performed on Nb 3 Sn strands in which the superconducting filaments were not twisted.<br />

Optimisation of NbTi strand for PF1/PF6 performance<br />

The original strand specification for the high-field ITER PF coils (P1/P6) was based on the LHC strand and<br />

was 2900A/mm 2 at 5 T and 4.2 K. Using the recommended scaling formula, this gave an acceptable<br />

predicted critical current density at the P1/P6 critical conditions.<br />

[A4.3] F. Bellina et al., IEEE Trans. Appl. Supercond. 16-2, 1798 (2006)<br />

[A4.4] L. Muzzi et al., Pure bending strain experiments on jacketed Nb 3 Sn strands for ITER, presented at the Applied Superconductivity<br />

Conference - ASC (Seattle 2006)<br />

References<br />

65<br />

Progress Report 2006


A4 Superconductivity<br />

A Fusion Programme<br />

However, it seems that NbTi strands have been optimised for low-temperature performance at the<br />

expense of the Jc at higher temperatures. The scaling formula is essentially an envelope of the<br />

maximum achieved current density at each field/temperature and appears to be un-representative<br />

of these LHC strands at 6 T and 6.5 K. The difference in Jc (measured vs predicted) is substantial<br />

and only some of the variation may be due to measurement errors, as small errors at temperatures<br />

above 6 K produce a large change in critical current.<br />

At the end of 2006, <strong>ENEA</strong> was charged with developing and producing at least 50 kg of Ni-plated<br />

NbTi strand according to the ITER P1/P6 strand specification, with optimised current carrying<br />

capabilities at higher temperatures and fields (TW6-TMSC-NbTi). The minimum required non-Cu Jc<br />

at 6.5 K and 6 T is 200A/mm 2 . The optimisation processes for NbTi are quite well understood and<br />

the performance at 6.5 K and 6 T can be improved by changing the process parameters during<br />

production, e.g., adjustments to the intermediate annealing steps. The activity will be carried out<br />

during 2007.<br />

A4.3 JT-60SA<br />

The Broader Approach is a project related to the ITER Accompanying Programme and involves<br />

cooperation between Japan and the EU for the construction of a new tokamak machine in Japan,<br />

JT-60SA. In Europe, CEA and <strong>ENEA</strong> have been assigned the specific tasks to design, construct and<br />

test the 18 toroidal plasma confinement<br />

magnets (fig. A4.3) made of NbTi strands. <strong>ENEA</strong><br />

is in charge of coordinating all the related EU<br />

activities and consequently has been involved in<br />

the conductor and coil design<br />

In 2006, a preliminary assessment of the toroidal<br />

200 400 400<br />

magnet characteristics in regard to the<br />

expected operative conditions was carried out.<br />

400<br />

<strong>ENEA</strong> is working on a consistent conceptual<br />

400<br />

600<br />

600<br />

design concerning the strand choice as well as<br />

the conductor and coil layout definition. At the<br />

moment, the definition of toroidal-coil design is<br />

still being discussed among the members of the<br />

joint project. Related to this activity, the <strong>ENEA</strong><br />

Fig. A4.3 – Magnetic system of the Japanese tokamak Frascati facility for testing and characterising<br />

JT60SA: in red the 18 toroidal coils to be designed, superconducting strands at variable<br />

built and tested in the EU<br />

temperatures (4.2 K – 20 K) and magnetic fields<br />

(up to 12 T) has been considerably upgraded in<br />

terms of accuracy, repeatability and signal-to-noise ratio, becoming one of the most reliable and<br />

versatile among the few available in Europe for this kind of characterisation. It has allowed an<br />

extended campaign of NbTi strand characterisation, focussed on the foreseen operative conditions<br />

of JT-60SA.<br />

A4.4 High–Temperature Superconducting Materials<br />

Evolution and control of cube texture in Ni-W substrates for YBCO-coated<br />

conductors<br />

The realisation of high critical current density YBe 2 Cu 3 O 7-x -based coated conductors with the<br />

rolling-assisted biaxially textured substrate (RABiTS) approach is primarily related to the sharpness<br />

Progress Report 2006<br />

66


of cube texture developed in the substrate.<br />

Among the various Ni–based tapes proposed,<br />

Ni-W alloys have attracted particular interest<br />

because of the enhanced mechanical<br />

properties and reduced magnetism with<br />

respect to pure Ni, and the sharp and almost<br />

pure cube texture that can be obtained after<br />

recrystallization of cold rolled tapes.<br />

a) 600°C b) 700°C c) 800°C<br />

Fig. A4.4 – (111) pole figures for three Ni-W samples annealed at<br />

a) 600, b) 700 and c) 800°C and quenched to room temperature<br />

The texture of highly (>90%) deformed fcc<br />

metals with a medium-high stacking fault energy (SFE) is concentrated in the so-called β-fibre, known as<br />

the stable end position of lattice rotations occurring during cold rolling. The development of cube texture<br />

through recrystallization is directly related to the deformation texture, as the stronger the β-fibre the sharper<br />

the cube texture in the (111) pole figure. During annealing, the deformation texture evolves into the cube<br />

texture. Annealing up to 600°C does not affect the deformation texture in Ni 5 at% W (Ni–W) tapes, as no<br />

orientation difference with respect to the as-rolled samples can be detected (fig. A4.4).<br />

Conversely, at 700°C a structural modification appears, with the coexistence of cube and deformation<br />

textures, since four symmetric poles, at tilt angle χ=54.7° and azimuthal angles ϕ=45°, 135°, 225° and<br />

315°, are superimposed on the pre-existent texture in the (111) pole figures. Finally, for temperatures higher<br />

than 800°C the sample is cube oriented and no residual deformation texture is detectable; the only<br />

identifiable poles other than cube are due to {221}, namely cube twins, which are intrinsically related<br />

to the recrystallization of cube grains. However, indications of microstructural modifications already at<br />

600°C are revealed by a Monte Carlo procedure on<br />

θ–2θ x-ray diffraction peaks, since an evaluation of the<br />

microstrain contribution to peak broadening is provided.<br />

No remarkable modification is produced up to 500°C,<br />

while above this temperature a decrease in microstrain<br />

is evident, indicating a relaxing of the lattice defects by<br />

the decrease in the dislocation density, i.e., the material<br />

underwent the recovery phase (fig. A4.5). In fact, during<br />

this stage, part of the energy stored during deformation<br />

4×10 -3<br />

3×10 -3<br />

2×10 -3<br />

400<br />

300<br />

200<br />

annihilation and subgrain formation, leading to<br />

1×10 -3 100<br />

modification of several physical properties, such as<br />

0 200 400 600 800 1000<br />

is released through dislocation rearrangement/<br />

hardness and electrical conductivity, without affecting<br />

Annealing temperature (°C)<br />

lattice orientation. Further microstrain reduction above<br />

700°C is due to the growth of strain-free oriented<br />

grains, namely recrystallization, which is complete<br />

above 800°C.<br />

Fig. A4.5 – Evolution of microstrain and Vickers<br />

hardness for Ni-W samples annealed at different<br />

temperatures and quenched to room temperature<br />

After complete recrystallization the tapes may exhibit, to the naked eye, a more or less opalescent surface.<br />

This feature is the result of the diffusion of light coming from pronounced grain boundaries, which are<br />

normally high-angle boundaries, i.e., with a relative misorientation greater than about 15°. This is the case<br />

of cube twins, often arranged in longitudinal bands. It was shown that the formation of components other<br />

than cubes is related to the grain size of the bulk material before cold rolling (initial GS) (fig. A4.6). In<br />

particular, the area of cube orientation decreases because of the increase both in cube twins and in noncube<br />

orientation as the initial GS becomes larger. These data indicate that twin formation is related to both<br />

the SFE and the deformed state (fig. A4.7, A4.8). The resulting direct relation between cube twins and<br />

non-cube area densities suggests that their formation is controlled by a common parameter. This<br />

correlation is supported by data from several samples of Ni-V, Ni-Cr and Ni-W. In particular, large non-cube<br />

grain fractions correspond to samples subjected to a deformation degree below 95%, in which the few<br />

cube grains were almost invariably twinned.<br />

Both in- and out-of-plane distributions of the cube orientation measured by x ray are in agreement with<br />

electron backscattering diffraction (EBSD) analysis in terms of cube texture coarsening, as an increase in<br />

Microstrain<br />

Vickers hardness HV 200<br />

67<br />

Progress Report 2006


A4 Superconductivity<br />

a) b)<br />

6<br />

cube twin<br />

non–cube<br />

A Fusion Programme<br />

100 μm<br />

0 10 20 30 40 50 60<br />

Deviation from {001} (°)<br />

FWHM (degree)<br />

9<br />

7<br />

Δω(RD)<br />

Δω(TD)<br />

Δφ<br />

5<br />

10 30 50 70<br />

Initial grain size (μm)<br />

Fig. A4.8 – FWHM of (200) rocking curves, along<br />

both rolling (empty triangles) and transverse<br />

directions (full triangles), and of (111) φ-scans<br />

100 μm<br />

0 10 20 30 40 50 60<br />

Deviation from {001} (°)<br />

Fig. A4.6 – EBSD misorientation maps for Ni-W samples with initial GS of<br />

19 µm a) and 63 µm b)<br />

the spread around the {001} ideal orientation for<br />

larger initial GS is observed. As a consequence of this<br />

behaviour, a broader distribution of the cube texture is<br />

observed in substrates with reduced cube area fraction.<br />

This kind of relationship seems to be a general feature<br />

since it has been observed in several Ni-based substrates.<br />

This result is of great conceptual and practical importance<br />

because hindering cube twin formation not only provides<br />

larger cube areas, but leads to sharper cube textures as<br />

well [A4.5].<br />

Nickel-copper alloys as textured substrates<br />

for YBCO–coated conductors<br />

(empty circles) for Ni-W samples with different<br />

Ni-Cu-Co alloy tapes with different relative concentrations<br />

initial GS<br />

were studied as textured substrates for YBCO-coated<br />

conductor application. A small amount of cobalt was<br />

added in order to enhance the oxidation resistance of Ni-Cu alloy. 100-μm-thick tapes were<br />

obtained through conventional cold rolling to a deformation degree of 97% followed by recrystalliza -<br />

tion at high temperature. The use of different thermal treatments made it possible to obtain area<br />

densities of cube orientation as high as 95% (figs. A4.9, A4.10). The substrate was thoroughly<br />

characterised by means of x-ray diffraction, EBSD and scanning electron microscopy (SEM)<br />

analyses. Electrical resistivity, mechanical properties and oxidation resistance of this substrate will<br />

be compared with those exhibited by Ni, Ni-W and Ni-Cu tapes.<br />

Area fraction (%)<br />

4<br />

2<br />

0<br />

10 30 50 70<br />

Initial grain size (μm)<br />

Fig. A4.7 – Non-cube and cube twin area density<br />

drawn from EBSD measurements for Ni-W<br />

samples with different initial GS<br />

A Pd transient layer was epitaxially grown prior to depositing<br />

conventional CeO 2 /YSZ/CeO 2 buffer layer architecture in<br />

order to passivate the Ni-Cu-Co substrate. The deposition<br />

conditions for the Pd layer were optimised in order to obtain<br />

a particularly sharp out-of-plane orientation, so that the full<br />

width at half maximum (FWHM) of the rocking curves in the<br />

transverse direction (TD) through the (002) reflection drops<br />

RD<br />

TD<br />

Fig. A4.9 – EBSD map for a recrystallized Ni-Cu-Co alloy substrate.<br />

Red, green and blue colours refer to {100}, {110} and {111} planes<br />

Progress Report 2006<br />

68


{1,1,1}<br />

32<br />

RD<br />

Fig. A4.10 – (111) pole figure obtained from EBSD<br />

data for a recrystallized Ni-Cu-Co sample<br />

16<br />

8<br />

TD<br />

4<br />

2<br />

1<br />

0.5<br />

0.13<br />

from about 9° of Ni-Cu-Co to 2.1° of Pd<br />

layer; whereas in the rolling direction (RD)<br />

these values attain about 6 and 1.7°,<br />

respectively. This sharp texture is preserved<br />

and both CeO 2 and YSZ films exhibit the<br />

same out-of plane orientation (fig. A4.11).<br />

The encouraging structural properties of the<br />

buffer layer architecture obtained indicate<br />

that this alloy is a promising alternative<br />

substrate for the realisation of<br />

YBCO–coated conductors.<br />

Intensity (arb. units)<br />

7×10 4<br />

5×10 4<br />

3×10 4<br />

1×10 4<br />

TD NiCuCo-Pd 1<br />

TD NiCuCo-Pd 2<br />

RD NiCuCo-Pd 1<br />

RD NiCuCo-Pd 2<br />

10<br />

10 15 20 25 30 35<br />

θ (degree)<br />

Fig. A4.11 – Rocking curves around (002) reflection of Pd films grown at<br />

different temperatures on Ni-Cu-Co substrate. A consistent sharpening<br />

of the out-of-plane orientation is attained for higher deposition<br />

temperatures<br />

MOD-TFA YBCO films<br />

It has been demonstrated that metal-organic deposition (MOD) using trifluoroacetate (TFA) precursors is<br />

the most suitable for epitaxial YBCO deposition. In the MOD-TFA method, a fluorine containing coating<br />

solution decomposes to fluorides which, in turn, undergo different chemical reactions during the hightemperature<br />

firing process (700 – 800°C) in controlled atmosphere to convert to oxides.<br />

The precursor solutions for YBCO were prepared by sonicating the mixture of Y, Ba and Cu acetates in a<br />

1:2:3 cation ratio with a stoichiometric quantity of trifluoroacetic acid in de-ionized water. The resulting<br />

solution was slowly dried at low temperature to form a glassy blue resin. The precursor solution was<br />

deposited both on (00l)-oriented SrTiO 3 single crystals and on Ni-W/Pd/CeO 2 /YSZ/CeO 2 templates by<br />

spin coating. The resulting gel films were treated in two heating stages to obtain the YBCO<br />

superconducting films. The YBCO films obtained under these conditions are about 250 nm thick.<br />

The x-ray diffraction (XRD) pattern of θ–2θ scans for YBCO/CeO 2 /YSZ/CeO 2 /Pd/Ni-W exhibits only the<br />

(00l) YBCO peaks. No (h00) reflections due to a-axis oriented grains were observed. The presence of the<br />

(111) reflection of YSZ and CeO 2 indicates a small fraction of (111) oriented grains in these films. The (002)<br />

to (111) peak intensity ratio is of about 10 2 . The rocking curve through the (002)Ni-W, (002)YSZ, (002)CeO 2<br />

and (005)YBCO peaks have an out-of-plane FWHM of 8.8°, 4.2°, 3.8° and 3.4°, respectively. The small<br />

values of FWHM for the YSZ and CeO 2 with respect to the Ni-W substrate is correlated to the Pd film. The<br />

in-plane crystallographic relationship of the structure is [100]YBCO||[110]CeO 2 ||[110]YSZ||[100]Ni-W.<br />

The surface of YBCO/CeO 2 /YSZ/CeO 2 /Pd/Ni-W films is free of cracks but has some holes. In spite of the<br />

voids, the c-axis oriented grains are well connected. Furthermore, YBCO grains are connected over pores.<br />

[A4.5] A. Vannozzi et al., Supercond. Sci. Technol. 19, 1240-1245 (2006)<br />

References<br />

69<br />

Progress Report 2006


A4 Superconductivity<br />

A Fusion Programme<br />

Intensity (counts/s)<br />

100 nm<br />

Fig. A4.12 – Film surface of YBCO TFA grown on<br />

CeO 2 /YSZ/CeO 2 /Pd/Ni-W<br />

2.0×10 5<br />

1.5×10 5<br />

1.0×10 5<br />

0.5×10 5<br />

BZO(100)<br />

19 20 21 22 23 24<br />

(100)<br />

(200)<br />

STO (100)<br />

(400)<br />

(500)<br />

BZO(200)<br />

40 42 44 46 48<br />

STO (200)<br />

Introduction of artificial pinning sites in YBCO films<br />

(700)<br />

The spherical particulates are<br />

nanocrystallites of CuO<br />

(fig. A4.12). The high quality<br />

of the YBCO films is<br />

confirmed by the T c values<br />

(90.9 K) and the reduced<br />

transition widths (ΔT∼1.5 K)<br />

(fig. A4.13).<br />

J c values as high as<br />

1 MA/cm 2 are reported at<br />

84 K, reaching 2.7 MA/cm 2<br />

at 77 K for YBCO TFA films<br />

deposited on SrTiO 3 single<br />

crystals. The development of<br />

MOD-TFA YBCO films on<br />

long length CeO 2 /YSZ/<br />

CeO 2 /Pd/Ni-W template is in<br />

progress [A4.6].<br />

One of the most effective ways to improve the pinning efficiency of magnetic flux vortices in YBCO<br />

films is the introduction of epitaxial second–phase nanoinclusions in the YBCO matrix. This<br />

technique has gained relevant interest due to the possibility of increasing the irreversibility field (H irr ),<br />

which limits high magnetic field performance.<br />

This goal has been pursued by growing YBCO thin films with the pulsed laser deposi tion (PLD)<br />

method from com posite targets obtain ed by adding BaZrO 3 (BZO) powder in molar percents<br />

ranging from 2.5 to 7%. The presence of BZO epitaxial inclusions inside the films has been checked<br />

by XRD analysis (fig. A4.14).<br />

As already reported in the literature, the introduction of second-phase nanoinclusions progressively<br />

lowers the critical temperature T c of YBCO thin films (fig. A4.15).<br />

Analysis of the transport properties shows the improvement of pinning efficiency in YBCO films with<br />

BZO inclusions. Self-field critical current densities are increased by BZO addition, ranging from 1.23<br />

MA/cm 2 for pure YBCO film to 2.22 MA/cm 2 recorded for 2.5 mol.% BZO-YBCO film. All the BZO<br />

added films exhibit increased critical current densities in the whole magnetic field range inspected<br />

and higher irreversibility field values, with the 5 mol.% BZO-YBCO film the best in field performances<br />

(fig. A4.16a)). The improvement in the transport properties in BZO samples can be ascribed to the<br />

introduction of extended defects elongated along the YBCO c-axis, as shown by a prominent peak<br />

Resistance (Ω)<br />

0<br />

0 20 40 60 80 100 120<br />

2θ (degree)<br />

STO (300)<br />

BZO(400)<br />

20<br />

10<br />

8<br />

6 T C =90.9 K<br />

4<br />

2<br />

0<br />

80 90 100<br />

0<br />

0 100 200 300<br />

Temperature (K)<br />

Fig. A4.13 – R(T) plot for YBCO TFA grown on<br />

CeO 2 /YSZ/CeO 2 /Pd/Ni-W<br />

STO (400)<br />

94 95 96 97 98<br />

Fig. A4.14 – X-ray θ-2θ diffraction spectrum showing the presence of<br />

BaZrO 3 epitaxial second phase inside the YBCO matrix<br />

Progress Report 2006<br />

70


Normalised resistance<br />

1.2<br />

0.8<br />

0.4<br />

YBCO-STO<br />

YBCO-BZO (2.5%)-STO<br />

YBCO-BZO (5%)-STO<br />

YBCO-BZO (7%)-STO<br />

0<br />

80 85 90 95 100<br />

Temperature (K)<br />

a)<br />

Critical temperature (K)<br />

90<br />

88<br />

86 YBCO-STO<br />

YBCO-BZO (2.5%)-STO<br />

YBCO-BZO (5%)-STO<br />

YBCO-BZO (7%)-STO<br />

84<br />

0 2 4 6 8<br />

BaZrO 3 nominal concentration (vol.%)<br />

b)<br />

Fig. A4.15 – Normalised<br />

resistance as a function of the<br />

temperature for YBCO films<br />

with BZO molar concentration<br />

ranging from 2.5 to 7% a).<br />

Dependence of the critical<br />

temperature T c on the BZO<br />

molar concentration b)<br />

at 0° (magnetic field parallel to the c-axis) in the critical current<br />

density dependence on the angle between the magnetic field<br />

direction and the direction normal to the film (fig. A4.16b)).<br />

Measurements of the microwave complex resistivity in the mixed<br />

state were carried out for films deposited on SrTiO 3 and sapphire<br />

single crystal substrates. The pinning frequency ν p , which<br />

represents a measure of the steepness of the potential well for the<br />

flux lines, can be estimated from complex resistivity. Very high<br />

values of about 50 GHz are attained between 60 and 80 K,<br />

indicating extremely high vortex pinning and steep potential wells.<br />

As expected, the ν p rapidly drops to zero as T approaches T c . It can<br />

be concluded that the intragrain vortex pinning at high microwave<br />

frequencies in YBCO films with BZO inclusion of nanometric size<br />

has been greatly improved with respect to films free of BZO<br />

inclusions.<br />

Magnetic characterisation of superconducting wires<br />

for fast ramped superconducting dipoles<br />

The INFN Dipoli Super Conduttori Rapidamente Pulsati<br />

2×10 5<br />

(DISCORAP) programme originates from the new requirement of<br />

μ 0 H=3 T<br />

developing fast-ramped superconducting dipoles for the FAIR<br />

μ 0 H=5 T<br />

accelerators at GSI, Darmstadt, Germany. It is a four-year program<br />

0<br />

to develop a fully working bent dipole 3.8 m long in its horizontal<br />

-100 -50 0 50 100<br />

cryostat. The dipole has to generate a field of 4.5 T with a ramping<br />

rate of 1 T/s.<br />

Angle (degree)<br />

Fig. A4.16 – a) Critical current density as a<br />

function of the applied magnetic field at T=77K<br />

Magnetic measurements in high magnetic field were carried out to<br />

for YBCO films with BZO content ranging from<br />

extract information about the intrinsic magnetization losses, critical<br />

2.5 to 7 mol.%. b) Dependence of the critical<br />

current, and filament size. Dissipation, when the magnetic field is<br />

current density on the angle between the<br />

rapidly changing, comes from the filament couplings, which are<br />

magnetic field direction and the direction normal<br />

connected through the metallic matrix. The magnetization M of<br />

to the film at T=77K recorded for the 7 mol.%<br />

NbTi and Nb 3 Sn wires was analysed with a vibrating sample<br />

BZO-YBCO sample<br />

magnetometer (VSM) operat ing in the range [300 - 4] K under a<br />

maximum field up to 12 T. All the tests were carried out in the zero field cooling (ZFC) situation to be able<br />

to record the purely diamagnetic response at low magnetic field, useful for studying the shielding regimes.<br />

Figure A4.17 shows magnetic measurements for a 2-μm filament prototype NbTi wire.<br />

[A4.6] A. Rufoloni et al., J. Phys.: Conf. Ser. 43, 199 (2006)<br />

Critical current density (A/cm 2 )<br />

Critical current density (A/cm 2 )<br />

10 5<br />

10 3<br />

T=77K a)<br />

YBCO-STO<br />

BZO (F2.5%)-STO<br />

BZO (F5%)-STO<br />

10 1 BZO (F7%)-STO<br />

0 4 8<br />

Magnetic induction (T)<br />

6×10 5<br />

4×10 5<br />

YBCO-BZO(F7%)-3 77K<br />

μ 0 H=100 mT<br />

μ 0 H=1 T<br />

b)<br />

References<br />

71<br />

Progress Report 2006


A4 Superconductivity<br />

A Fusion Programme<br />

Magnetic moment (emu)<br />

0<br />

-0.0005<br />

50<br />

-0.001<br />

transverse field<br />

parallel field<br />

0<br />

-0.0015<br />

SL8979S<br />

sample A-I=5.57 mm<br />

-0.002<br />

-50<br />

4 8 12 16<br />

T(K)<br />

transverse<br />

field 4.5 K<br />

Fig. A4.17 – Magnetic moment for low filament size NbTi wire (2006)<br />

MARIMBO experiment:<br />

application of MgB 2<br />

Activities regarding MgB 2<br />

superconductors have been<br />

devoted to fundamental<br />

aspects, such as the influence of<br />

the disorder introduced by<br />

-6 -4 -2 0 2 4 6 neutron irradiation on<br />

B(T)<br />

polycrystalline MgB 2 material<br />

and the MgB 2 phase nucleation<br />

by means of MgB 2 /Mg multilayers,<br />

and to more applicative features such as<br />

the stability properties of a MgB 2 multifilamentary<br />

tape.<br />

10 5<br />

The magnetic properties of polycrystalline MgB 2<br />

10 5<br />

10 4<br />

J @T=5 K, B=4 T<br />

0<br />

exposed to different neutron fluencies were<br />

P2<br />

0 10 17 10 18 10 19<br />

Fluence (cm 2 ) analysed to perform in-depth analysis of the<br />

P3.5 critical field and current density behaviour and to<br />

P3.7<br />

identify what scattering and pinning mechanisms<br />

P5<br />

P4<br />

P0<br />

come into play (fig. A4.18).<br />

10 4 P3<br />

P6<br />

P1<br />

In the second study the chemical composition<br />

3 6 9<br />

μ<br />

and electronic structure of the multi-layer films<br />

o H(Tesla)<br />

were analysed and compared with the<br />

Fig. A4.18 – Critical currents measured in samples<br />

corresponding MgB 2 bulk case to investigate the<br />

after different neutron doses (P)<br />

reasons for the low transition temperature typical<br />

of low-temperature processed MgB 2 films. Short<br />

straight samples of the Cu-stabilised, 14-filament MgB 2 tape, taken from a 1.6–km-length<br />

production manufactured by Columbus Superconductors, Genoa, were used to produce a cryogenfree,<br />

double pancake style, magnet. The conductor is a 3.6-mm-wide and 0.65-mm-thick tape,<br />

fabricated with the powder-in-tube (PIT) method. The tape is composed of a copper inner region<br />

delimited by an iron sheath and a nitrogen Niouter matrix where MgB 2 filaments are embedded. The<br />

superconducting fraction is less than 10% of the whole section. The tape edges were welded over<br />

3 cm on the bulk copper sample holder used for the tests, which were performed in a He gas flow<br />

cryostat. Two brass counter flow cooled current leads, designed for 200 A, were used to bias the<br />

tape. The wire was shielded by thick polystyrene from direct exposure to the cold gas. A 3-mm-wide<br />

heater, made of NiCr wire, was wound and glued in the middle of the tape. Voltage contacts at<br />

known positions were used to determine the presence of dissipative regimes. A calibrated cernox<br />

thermometer was located on the tape, a few mm from the heater side. Figure A4.19a) reports the<br />

heat propagation velocity ν p as a function of the delivered energy E at two temperatures and bias<br />

currents, while figure A4.19b) reports ν p as a function of the temperature at two values of bias<br />

current, each one triggered by a constant energy pulse.<br />

J c (A/cm 2 )<br />

V p (mm/s)<br />

T= 5 K<br />

J c<br />

(A/cm 2 )<br />

The ν p -vs.-energy curve indicates a fast increase in ν p at low heater energy followed by a weak<br />

dependence for higher energy values. This ν p (E) behaviour at low E values may be ascribed to the<br />

100<br />

60<br />

150<br />

a) b)<br />

μ 0 H=0 T<br />

20K 200A<br />

30K 100A<br />

20<br />

30<br />

0 0.5 1 1.5 2 2.5 15 20 25 30<br />

Heater energy (J)<br />

Temperature (K)<br />

90<br />

200A 2.25J<br />

150A 0.56J<br />

μ 0 H=0 T<br />

Fig. A4.19 – Normal zone<br />

propagation velocity as a<br />

function of a) heater energy and<br />

b) temperature<br />

Progress Report 2006<br />

72


short distance between voltage taps and heater, where the equilibrium balance between the heat loss by<br />

conduction and the generated heat is not yet achieved. The ν p increases with the temperature because<br />

dissipation increases, narrowing the temperature margin T g -T 0 , where T 0 and T g are the operating the<br />

generation temperature, respectively.<br />

Transport and thermal stability characterisation of HTS wires and tapes: analysis of<br />

quench propagation on YBCO-coated conductors<br />

A 45-cm–long AMSC 344 conductor sample<br />

was used, with a Ni-Cr resistive wire wound in<br />

the middle of the tape as heat source. The<br />

quench propagation was monitored by 12<br />

voltage taps distributed along the sample<br />

length. Figure A4.20 reports details of the<br />

electrical connections on the tape. The<br />

distance between voltage taps is 1 cm and the<br />

total active length (distance between V+ and V)<br />

is 32 cm. The Ni–Cr heater is in the region<br />

delimited by ch0 voltage taps. Figure A4.21<br />

shows a typical result for a set of<br />

measurements with increasing energy at<br />

T=80 K and I bias =35 A. Only ch0 and ch1<br />

values are plotted for clarity. The energy was<br />

varied by increasing the current, but keeping<br />

the pulse duration at 0.1 s. Up to 0.36 J a sharp<br />

increase in the ch0 voltage was revealed in<br />

correspondence to the current pulse (t=0 s) and<br />

then recovered after a few seconds. No other<br />

significant variations in the voltage readings<br />

were observed. For higher energy, propagation<br />

sets up as revealed by the increase of the ch1<br />

5 cm 6 cm 2.6 cm 2.5 cm 6 cm 5 cm<br />

| | | | | | | | | | | |<br />

-|--------|---|-------|---|----|---|----|---|-------|---|--------|-<br />

V+ ch2 ch1 ch0 ch3 ch4 V-<br />

Fig. A4.20 – Distribution and distance of voltage taps along the<br />

active region of the tape<br />

voltage. As expected, the process becomes faster as the energy increases. Heat propagation is stopped<br />

when the I bias is switched off (sharp drops of both ch0 and ch1 marked by arrows in fig. A4.21).<br />

Voltage (mV)<br />

7×10 -3<br />

5×10 -3<br />

3×10 -3<br />

T=80 K; l bias =35A (66% l c )<br />

l bias off<br />

1×10 -3 0<br />

0 5 10 15 20 25<br />

Time (s)<br />

run 21 ch0<br />

run 21 ch1<br />

run 22 ch0<br />

run 22 ch1<br />

run 23 ch0<br />

run 23 ch1<br />

run 24 ch0<br />

run 24 ch1<br />

run 25 ch0<br />

run 25 ch1<br />

run 26 ch0<br />

run 26 ch1<br />

Heat-generation experiments were carried out at 75 and 80 K for different values of I bias . The heat<br />

propagation velocity evaluated from ch1 as a function of the energy for both 75 and 80 K is reported in<br />

figure A4.22a) and b). As can be seen, V 1 increases with I bias . It should be noted that the propagation<br />

process in this tape is about two orders of magnitude slower than in typical NbTi multifilamentary wire and<br />

one slower than in MgB 2 tape.<br />

0.25J<br />

0.36J<br />

0.42J<br />

0.49J<br />

0.64J<br />

0.81J<br />

Fig. A4.21 – Time evolution of voltage along the tape<br />

Signal velocity V 1 (m/s)<br />

2.0×10 -2<br />

1.5×10 -2<br />

1.0×10 -2<br />

T=75K<br />

a)<br />

53% l c<br />

58% l c<br />

64% l c<br />

70% l c<br />

76% l c<br />

82% l c<br />

85% l c<br />

0.5×10 -2 0<br />

0 0.2 0.4 0.6 0.8 1 1.2<br />

Heater energy (J)<br />

Signal velocity V 1 (m/s)<br />

2.0×10 -2<br />

1.5×10 -2<br />

1.0×10 -2<br />

0.5×10 -2 0<br />

T=80K<br />

b)<br />

57%l c<br />

66%l c<br />

86%l c<br />

0 0.2 0.4 0.6 0.8 1 1.2<br />

Heater energy (J)<br />

Fig. A4.22 – Normal zone propagation velocity in the HTS tape at two different temperatures :a) 75 K and b) 80 K<br />

73<br />

Progress Report 2006


A5 Inertial Fusion<br />

A Fusion Programme<br />

The Fast Ion Generation Experiment (FIGEX) proposed and designed by the <strong>ENEA</strong> Inertial Physics<br />

and Technology Group [A5.1, A5.2] was performed at the Petawatt Facility of the Rutherford<br />

Appleton Laboratory (UK) during the first two months of 2006. The aim was to study a possible way<br />

to create by short laser pulses an ion source for inertial fusion energy (IFE) application. The Frascati<br />

ABC facility was used to determine the required pre-pulse contrast in the experiment [A5.3]. Analysis<br />

of the experimental results was mostly carried out at Frascati <strong>ENEA</strong>. A large fraction of the activity<br />

had to be devoted to preparing within a few months a software package for the ion spectrometer<br />

data processing. Preliminary results were available for an invited presentation at the European<br />

Conference on Laser Interaction with Matter held in Madrid in June 2006.<br />

Since FIGEX was designed for fast–ion generation (MeV/nucleon), a set of Thomson ion<br />

spectrometers was used as the key diagnostic. The detectors were plastic CR39 plates where each<br />

ion was registered as a pit. Ions on CR39 were registered along parabolas (one for each Z/A, where<br />

Z and A are the ion charge and mass numbers):<br />

V z 2<br />

H 2 x<br />

V2<br />

H 2 ( z x )2<br />

(A5.1)<br />

(A5.2)<br />

where (x, z) are the intrinsic coordinates taken with the origin in the point where ions with infinite<br />

energy would impinge and with the x-axis parallel to the magnetic field H; V and E nucl are the voltage<br />

applied to the plates and the energy per nucleon of the ion registered at the site (x, z). Equation A5.1<br />

represents in the plane (x, z) a parabola with the vertex at x=z=0 and the axis parallel to x, whereas<br />

A5.2 associates the specific energy to the coordinates (x,z) where the ion impinges.<br />

In analysing the experimental data, to find the intrinsic position of the origin and the direction of the<br />

axes it was sometimes useful to represent the pit positions in the plane E nucl ,Z/A) where parabolas<br />

become straight lines parallel to the E nucl - axis (see an example in fig. A5.1).<br />

A microscope driven by step motors was used to detect the position of the pits imprinted on the<br />

CR39. The software associated with the equipment generated information about several features of<br />

each pit, including their position with respect to a Cartesian coordinate system (u, v). These data<br />

were released as a text file for each CR39 plate.<br />

Rather complex software based on the Mathematica package was worked out and installed on a<br />

laptop computer that makes the utility transportable when needed. The software was designed in<br />

order to 1) find the intrinsic coordinate system where eqs. A5.1 and A5.2 hold; 2) recognise the Z/A<br />

corresponding to each parabola; 3) count the number of pits registered on each parabola; and 4)<br />

Progress Report 2006<br />

74


Fig. A5.1 – Example of ion registration in the intrinsic plane and<br />

in the (E nucl , Z/A) plane<br />

(x, z) plane<br />

associate to each pit the proper value of intrinsic<br />

coordinates (x,z), the specific energy E nucl and the<br />

distribution function in f( Enucl ) pertinent to each<br />

parabola and the associated average energy values,<br />

spread in energy, etc.<br />

(E nucl , Z/A) plane<br />

The code was designed to accomplish tasks 1, 2, 3,<br />

4 and to perform ionic distribution functions, global<br />

calculations relative to the complete set of<br />

spectrometers (6) aligned along different directions<br />

around the target and to study the angular<br />

distributions for number and energy (fig. A5.2).<br />

This programme was worked out as follows: First of<br />

all the Z/A expected in the experiment (expected<br />

contaminants included) were evaluated and the corresponding parabolas evaluated by eq. A5.1. Then the<br />

intrinsic coordinates were found by superposing (by electronic handling) the experimental parabolas on the<br />

theoretical ones given by eq. A5.1 as in figure A5.3. Figure A5.4 reports an example of species recognition<br />

based on this method.<br />

2<br />

cosθ<br />

- view<br />

LARGE<br />

θ<br />

- view<br />

1.5<br />

1<br />

θ<br />

0<br />

0.5<br />

0<br />

-1 -0.5 0 0.5<br />

cosθ<br />

1<br />

Laser beam<br />

Fig. A5.2 – Example of angular distribution calculations<br />

Target surface<br />

[A5.1] A. Caruso and C. Strangio, Laser Part. Beams 19, 295 (2001)<br />

[A5.2] C. Strangio and A. Caruso, Laser Part. Beams 23, 33 (2005)<br />

[A5.3] C. Strangio et al., A study for target modification induced by the prepulse in petawatt-class light-matter interaction experiments,<br />

presented at the 28 th ECLIM Proceedings (2004)<br />

References<br />

75<br />

Progress Report 2006


A5 Inertial Fusion<br />

A Fusion Programme<br />

Fig. A5.3 – The intrinsic coordinates are found by superposing the theoretical parabolas on the experimental. a) Initial<br />

relative positions of the theoretical and experimental patterns. b) The two patterns have been superposed by electronic<br />

handling and the species are identified<br />

O8<br />

C6<br />

Si14<br />

H N7<br />

Si12<br />

Si13 O7 N6<br />

Si10<br />

C5 Si11 O6 N5 C4 Si9 O5<br />

a) b)<br />

Si8<br />

N4<br />

Si7<br />

C3<br />

O4<br />

Si6<br />

N3<br />

O3<br />

Si5<br />

C2<br />

Si4<br />

N2<br />

O2<br />

C1<br />

Si3<br />

Si2<br />

N1<br />

O1<br />

Si1<br />

Fig. A5.4 – Intrinsic coordinates and ion recognition by<br />

the method of superposing the theoretical curves on the<br />

experimental pattern. Green labels represent missing<br />

elements<br />

To count the pits for each Z/A it was necessary<br />

to isolate the corresponding parabola from the<br />

others and from the background. The code<br />

performed this task by taking a strip around<br />

each parabola having width assigned ad hoc<br />

as input. The coordinates of the pits in each<br />

parabola were recorded in a file and used to<br />

evaluate the associated specific energy E nucl<br />

through eq. A5.2. From the files the distribution<br />

function of specific energy for each species<br />

was evaluated (see an example in fig. A5.5).<br />

Once the files pertinent to the number and<br />

energy distribution for each Z/A are known all<br />

the calculations relative to the ion charge<br />

distribution functions are possible, with the<br />

limits determined by the ion species mixing in<br />

each Z/A (fig. A5.6).<br />

Progress Report 2006<br />

76


800<br />

600<br />

400<br />

200<br />

0<br />

60<br />

40<br />

20<br />

200<br />

150<br />

100<br />

50<br />

0<br />

Si8-N4<br />

175<br />

Si9<br />

150<br />

800<br />

C4<br />

600<br />

100<br />

400<br />

50<br />

200<br />

0<br />

0<br />

0.5 1 1.5 2 2.5 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 0.5 1 1.5 2 2.5 3<br />

MeV/Nucl MeV/Nucl MeV/Nucl<br />

Si10-N5<br />

0<br />

0.4 0.6 0.8 1 1.2 1.4<br />

MeV/Nucl<br />

20<br />

15<br />

10<br />

5<br />

C5<br />

0.5 1 1.5 2 2.5<br />

MeV/Nucl<br />

Si14-N7-C6-O8<br />

0<br />

0.4 0.5 0.6 0.7 0.8 0.9<br />

MeV/Nucl<br />

140<br />

O6<br />

120<br />

80<br />

40<br />

0<br />

0.2 0.4 0.6 0.8 1 1.2 1.4<br />

MeV/Nucl<br />

30<br />

20<br />

10<br />

Si12-N6<br />

0<br />

0.6 0.8 1 1.2 1.4<br />

MeV/Nucl<br />

30<br />

20<br />

10<br />

0<br />

Si11<br />

0.5 0.6 0.7 0.8 0.9 1 1.1<br />

MeV/Nucl<br />

40<br />

Si13<br />

30<br />

20<br />

10<br />

0<br />

0.4 0.6 0.8 1 1.2 1.4<br />

MeV/Nucl<br />

Fig. A5.5 – Example of ion distribution function<br />

calculations for a Thomson ion spectrometer<br />

Fig. A5.6 – Example of ionization distribution functions<br />

Analysis of the experiment is expected to be completed<br />

within the first months of 2007 and part of the results<br />

will be available for presentation as an invited talk at the<br />

7 th Symposium on Current Trends in International<br />

Fusion Research: A Review (5-9 March 2007,<br />

Washington, DC, U.S.A.).<br />

0.325<br />

0.195<br />

0.065<br />

Si<br />

N<br />

2 6 10 14<br />

Z<br />

77<br />

Progress Report 2006


A6 Publications, Patents and Events<br />

A Fusion Programme<br />

Articles<br />

A6.1 Publications<br />

G. VLAD, S. BRIGUGLIO, G. FOGACCIA, F. ZONCA, M. SCHNEIDER: Alfvénic instabilities driven by fusion<br />

generated alpha particles in ITER scenarios<br />

Nucl. Fusion 46, 1-16 (2006)<br />

G. CARUSO, H.W. BARTELS, M. ISELI, R. MEYDER, S. NORDLINDER, V. PASLER, M.T. PORFIRI:<br />

Simulation of cryogenic He spills as basis for planning of experimental campaign in the EVITA facility<br />

Nucl. Fusion 46, 51-56 (2006)<br />

A.A. TUCCILLO, F. CRISANTI, X. LITAUDON, YU.F. BARANOV, A. ECOULET, M. BECOULET, L. BERTALOT,<br />

C.D. CHALLIS, R. CESARIO, M.R. DE BAAR, P.C. DE VRIES, B. ESPOSITO, D. FRIGIONE, L. GARZOTTI, E.<br />

GIOVANNOZZI, C. GIROUD, G. GORINI, C. GORMEZANO, N.C. HAWKES, J. HOBIRK, F. IMBEAUX, E.<br />

JOFFRIN, P.J. LOAS, J. MAILLOUX, P. MANTICA, M.J. MANTSINEN, D. MAZON, D. MOREAU, A. MURARI, V.<br />

PERICOLI-RIDOLFINI, F. RIMINI, A.C.C. SIPS, O. TUDISCO, D. VAN EESTER, K.-D. ZASTROW AND JET-<br />

EFDA WORK-PROGRAMME CONTRIBUTORS: Development on JET of advanced tokamak operation for ITER<br />

Nucl. Fusion 46, 214-224 (2006)<br />

F. SANTINI: Non-thermal fusion in a beam plasma system<br />

Nucl. Fusion 46, 225-231 (2006)<br />

P. BATISTONI, U. FISCHER, M. ANGELONI, P. BEM, I. KODELI, P. PERESLAVTSEV, L. PETRIZZI, M.<br />

PILLON, K. SEIDEL, S. P. SIMAKOV, R. VILLARI: Neutronics design and supporting experimental activities<br />

in the EU<br />

Fusion Eng. Des. 81, 1169-1181 (2006)<br />

M. ANGELONE, P. BATISTONI, M. LAUBENSTEIN, L. PETRIZZI, M. PILLON: Neutronics experiment for the<br />

validation of activation properties of DEMO materials using real DT neutron spectrum at JET<br />

Fusion Eng. Des. 81, 1485-1490 (2006)<br />

M.T. PORFIRI, N. FORGIONE, S. PACI, A. RUFOLONI: Dust mobilization experiments in the context of the<br />

fusion plants - STARDUST facility<br />

Fusion Eng. Des. 81, 1353-1358 (2006)<br />

T. PINNA, J. IZQUIERDO, M.T. PORFIRI, J. DIES: Fusion component failure rate database (ECFR-DB)<br />

Fusion Eng. Des. 81, 1391-1395 (2006)<br />

L. PETRIZZI, M. ANGELONE, P. BATISTONI, U. FISCHER, M. LOUGHLIN, R. VILLARI: Benchmarking of<br />

Monte Carlo based shutdown dose rate calculations applied in fusion technology: from the past experience<br />

a future proposal for JET 2005 operation<br />

Fusion Eng. Des. 81, 1417-1423 (2006)<br />

Progress Report 2006<br />

78


M. ANGELONE, M. PILLON, A. BALDUCCI, M. MARINELLI, E. MILANI, M.E. MORGADA, G. PUCELLA,<br />

A. TUCCIARONE, G. VERONA-RINATI, K. OCHIAI, T. NISHITANI: Radiation hardness of a polycrystalline chemicalvapor-deposited<br />

diamond detector irradiated with 14 MeV neutrons<br />

Rev. Sci. Instrum. 77, 023505/1-7 (2006)<br />

C. CASTALDO, U. DE ANGELIS, V.N. TSYTOVICH: Screening and attraction of dust particles in plasmas<br />

Phys. Rev. Letts 96, 075004/1-4 (2006)<br />

S. TOSTI, L. BETTINALI, F. GIORDANO, E. SOLDANO, G. SCIOCCHETTI: A novel permeation method to measure<br />

volumes<br />

Measurement 39, 186-194 (2006)<br />

S.E. SEGRE, V. ZANZA: Derivation of the pure Faraday and Cotton-Mouton effects when polarimetric effects in a<br />

Tokamak are large<br />

Plasma Phys. Control. Fusion 48, 339-351 (2006)<br />

G. MICCICHÉ, G. COLLINA, L. MURO, B. RICCARDI: IFMIF repraceable backplate: remote handling activities,<br />

rescue procedures and evaluation of a prototype reliability<br />

Fusion Eng. Des. 81, 879-885 (2006)<br />

M. SAMUELLI, L. RAPEZZI, M. ANGELONE, M. PILLON, M. RAPISARDA, S. VITULLI: Unconventional plasma<br />

focus devices<br />

IEEE Trans. Plasma Sci. 34, 1, 36-54 (2006)<br />

A. BALDUCCI, M. MARINELLI, E. MILANI, M.E. MORGADA, G. PUCELLA, M. SCOCCIA, A. TUCCIARONE, G.<br />

VERONA-RINATI, M. ANGELONE, M. PILLON, R.POTENZA, C. TUVÉ: Growth and characterization of single<br />

crystal CVD diamond film based nuclear detectors<br />

Diamond Rel. Mater. 15, 292-295 (2006)<br />

F. ZONCA, L. CHEN: Resonant and non-resonant particle dynamics in Alfvén mode excitations<br />

Plasma Phys. Control. Fusion 48, 537-556 (2006)<br />

L. BERTALOT, B. ESPOSITO, Y. KASCHUCK, D. MAROCCO, M. RIVA, A. RIZZO, D. SKIPINTSEV: Fast digitizing<br />

techniques applied to scintillation detectors<br />

Nucl. Phys. B (Proc. Suppl.) 150, 78-81 (2006)<br />

D. MAISONNIER, I. COOK, P. SARDAIN, L. BOCCACCINI, L. DI PACE, L. GIANCARLI, NORJAITRA PRACHAI, A.<br />

PIZZUTO AND PPCS TEAM: DEMO and fusion power plant conceptual studies in Europe<br />

Fusion Eng. Des. 81, 1123-1130 (2006)<br />

M. ROMANELLI, F. BOMBARDA, C. BOURDELLE, M. DE BENEDETTI, B. ESPOSITO, D. FRIGIONE, C.<br />

GORMEZANO, E. GIOVANNOZZI, G.T. HOANG, M. LEIGHEB, M. MARINUCCI, D. MAROCCO, C. MAZZOTTA, G.<br />

REGNOLI, C. SOZZI, F. ZONCA: Confinement and turbulence study in the Frascati tokamak upgrade high field and<br />

high density plasmas<br />

Nucl. Fusion 46, 412-418 (2006)<br />

P. BATISTONI: Il contributo italiano a ITER e al programma fusione<br />

La Termotecnica, Anno LX, 5, 32-34 (2006)<br />

S. TOSTI, A. BASILE, F. BORGOGNONI, L. BETTINALI, C. RIZZELLO: Pd membrane reactor design<br />

Desalination 200, 676-678 (2006)<br />

S. TOSTI, L. BETTINALI: Volumes measurement by means of membranes<br />

Desalination 200, 140-141 (2006)<br />

P. BURATTI, B. ALPER, S.V. ANNIBALDI, A. BECOULET, P. BELO, J. BUCALOSSI, M. DE BAAR, P. DE VRIES,<br />

79<br />

Progress Report 2006


A6 Publications, Patents and Events<br />

D. FRIGIONE, C. GOMERZANO, E. JOFFRIN, P. SMEULDERS AND JET EFDA CONTRIBUTORS: Study of<br />

slow n=1, m=1 reconnection in JET discharges with low central magnetic shear<br />

Plasma Phys. Control. Fusion 48, 1005-1018 (2006)<br />

A Fusion Programme<br />

R. CESARIO, A. CARDINALI, C. CASTALDO, F. PAOLETTI, V. FUNDAMENSKI, S. HACQUIN: Spectral<br />

broadening induced by parametric instability in lower hybrid current drive experiments of tokamak plasmas<br />

Nucl. Fusion 46, 462-476 (2006)<br />

F. ALLADIO, P. COSTA, A. MANCUSO, P. MICOZZI, S. PAPASTERGIOU, F. ROGIER: Design of the Proto-<br />

Sphera experiment and of its first step (MULTI-PINCH)<br />

Nucl. Fusion 46, S613-S624 (2006)<br />

S. TOSTI, A. BASILE, L. BETTINALI, F. BORGOGNONI, F. CHIARAVALLOTI, F. GALLUCCI: Long-term tests<br />

of Pd-Ag thin wall permeator tube<br />

J. Membrane Sci. 284, 393-397 (2006)<br />

M. MATTIOLI, G. MAZZITELLI, K.B. FOURNIER, M. FINKENTHAL, L. CARRARO: Updating of atomic data<br />

needed for ionization balance evaluations of krypton and molybdenum<br />

J. Phys. B: At. Mol. Opt. Phys. 39, 4457-4489 (2006)<br />

A. BASILE, S. TOSTI, G. CAPANNELLI, G. VITULLI, A. IULIANELLI, F. GALLUCCI, E. DRIOLI: Co-current<br />

and counter-current modes for methanol steam reforming membrane reactor: experimental study<br />

Catalysis Today 118, 237-245 (2006)<br />

A. BASILE, F. GALLUCCI, A. IULIANELLI, S. TOSTI, E. DRIOLI: The pressure effect on ethanol steam<br />

reformig in membrane reactor: experimental study<br />

Desalination 200, 671-672 (2006)<br />

F. ZONCA, S. BRIGUGLIO, L. CHEN, G. FOGACCIA, T.S. HAHM, A.V. MILOVANOV, G. VLAD: Physics of<br />

burning plasmas in toroidal magnetic confinement devices<br />

Plasma Phys. Control. Fusion 48, B15-B28 (2006)<br />

M. CIOTTI, A. NIJHUIS, P.L. RIBANI, L. SAVOLDI RICHARD, R. ZANINO: THELMA code electromagnetic<br />

model of ITER superconducting cables and application to the <strong>ENEA</strong> stability experiment<br />

Supercond. Sci. Technol 19, 987-997 (2006)<br />

U. DE ANGELIS, G. CAPOBIANCO, C. MARMOLINO, C. CASTALDO: Fluctuations in dusty plasmas<br />

Plasma Phys. Control. Fusion 48, B91-B97 (2006)<br />

A. FRATTOLILLO: New simple method for fast and accurate measurement of volumes<br />

Rev. Sci. Instrum 77, 045107 (2006)<br />

F. ALLADIO, P. MICOZZI: Behaviour of perturbed plasma displacement near regular and singular X-points<br />

for compressible ideal MHD stability analysis<br />

Phys. Plasmas 13, 082505 (2006)<br />

A. FRATTOLILLO: A simple automatic device for real time sampling of gas production by a reactor<br />

Rev. Sci. Instrum. 77, 065108 (2006)<br />

M.I.K. SANTALA, M.J. MANTSINEN, L. BERTALOT, S. CONROY, V. KIPTILY, S. POPOVICHEV, A. SALMI, D.<br />

TESTA, YU BARANOV, P. BEAUMONT, P. BELO, J. BRZOZOWSKI, M. CECCONELLO, M. DE BAAR, P. DE<br />

VRIES, C. GOWERS, J-M. NOTERDAEME, C. SCHLATTER, S. SHARAPOV AND JET-EFDA<br />

CONTRIBUTORS: Proton-triton nuclear reaction in ICRF heated plasmas in JET<br />

Plasma Phys. Control. Fusion 48, 1233-1253, (2006)<br />

Progress Report 2006<br />

80


S.E. SEGRE, V. ZANZA: Incident electromagnetic wave polarization and the resulting mode purity inside<br />

magnetized plasma<br />

Plasma Phys. Control. Fusion 48, 599-607 (2006)<br />

C. STRANGIO, A. CARUSO, S. YU. GUS’KOV, V.B. ROZANOV, A.A. RUPASOV: Interaction of a smoothed laser<br />

beam with supercritical-density porous targets on the ABC facility<br />

Quantum Electr. 36, 3, 424-428 (2006)<br />

R. BEDOGNI, A. ESPOSITO, M. ANGELONE, M. CHITI: Determination of the response to photons and thermal<br />

neutrons of new LiF based TL materials for radiation protection purposes<br />

IEEE Trans. Nucl. Sci. 53, 3, 1367-1370 (2006)<br />

M. ANGELONE, M. MARINELLI, E. MILANI, A. TUCCIARONE, M. PILLON, G. PUCELLA, G. VERONA-RINATI:<br />

Neutron detection and dosimetry using polycrystalline CVD diamond detectors with high collection efficiency<br />

Radiat. Prot. Dosim. 120, 1-4, 345-348 (2006)<br />

R. BEDOGNI, M. ANGELONE, A. ESPOSITO, M. CHITI: Inter-comparison among different TLD-based techniques<br />

in a standard multisphere assembly for the characterisation of neutron fields<br />

Radiat. Prot. Dosim. 120, 1-4, 369-372 (2006)<br />

Articles in course of publication<br />

P. BATISTONI: L’eredità di Chernobyl: i recenti rapporti del Chernobyl forum sulle conseguenze sulla salute<br />

sull’ambiente e sul sistema socio-economico a vent’anni dell’incidente<br />

Energia, Ambiente e Innovazione<br />

J.R. MARTIN-SOLIS, B. ESPOSITO, R. SANCHEZ, F.M. POLI, L. PANACCIONE: Enhanced production of runaway<br />

electrons during disruptive termination of discharges heated with lower hybrid power in the Frascati Tokamak<br />

Upgrade<br />

Phys. Rev. Letts<br />

A. VANNOZZI, A. RUFOLONI, G. CELENTANO, A. AUGIERI, L. CIONTEA, F. FABBRI, V. GALLUZZI, U.<br />

GAMBARDELLA, A. MANCINI, T. PETRISOR: Cube textured substrates for YBCO coated conductors:<br />

microstructure evolution and stability<br />

Supercond. Sci. Technol.<br />

A. AUGIERI, G. CELENTANO, U. GAMBARDELLA, L. CIONTEA, V. GALLUZZI, T. PETRISOR, J. HALBITTER:<br />

Analysis of angular dependence of pinning mechanisms on casubstituted YBa 2 Cu 3 O 7-δ epitaxial thin films<br />

Superconductors Sci. Technol.<br />

M. DE BENEDETTI AND JET EFDA CONTRIBUTORS: Observation of an intermediate rotation regime on JET<br />

Nucl. Fusion<br />

C. CASTALDO, S. RATYNSKAIA, V. PERICOLI, U. DE ANGELIS, L. PIERONI, E. GIOVANNOZZI, C. MARMOLINO,<br />

A. TUCCILLO, G.E. MORFILL: Effects of dust on electrostatic probe signal in tokamak plasmas<br />

Nucl. Fusion<br />

S. TOSTI, A. BASILE, F. BORGOGNONI, L. BETTINALI, F. GALLUCCI, C. RIZZELLO: Design and process study of<br />

Pd membrane reactors<br />

J. Membrane Sci.<br />

M. ROMANELLI, G.T. HOANG, C. BOURDELLE, C. GORMEZANO, E. GIOVANNOZZI, M. LEIGHEB, M. MARINUCCI,<br />

D. MAROCCO, C. MAZZOTTA, L. PANACCIONE, V. PERICOLI, G. REGNOLI, O. TUDISCO AND THE FTU TEAM:<br />

Parametric dependence of turbulent particle-transport in high-density electron heated tokamak plasmas<br />

Plasma Phys. Control. Fusion<br />

81<br />

Progress Report 2006


A6 Publications, Patents and Events<br />

A Fusion Programme<br />

M. ROMANELLI, M. LEIGHEB, L. GABELLIERI, L. CARRARO, M.E. PUIATTI, M. MATTIOLI, L. LAURO-<br />

TARONI, M. DE BENEDETTI, M. MARINUCCI, C. MAZZOTTA, L. PANACCIONE, G. REGNOLI, P.<br />

SMEULDERS, O. TUDISCO, S. NOVAK, C. SOZZI, M. VALISA, AND THE FTU TEAM: Turbulent<br />

transport of heavy impurities in tokamak electron heated high density plasmas: a study of FTU<br />

discharges<br />

Plasma Phys. Control. Fusion<br />

D. FRIGIONE, L. GARZOTTI, C.D. CHALLIS, M. DE BAAR, P. DE VRIES, M. BRIX, X. GARBET, N. HAWKES,<br />

A. THYAGARAJA, L. ZABEO, AND JET EFDA CONTRIBUTORS: Pellet injection and high density ITB<br />

formation in JET advanced tokamak plasmas<br />

Nucl. Fusion<br />

Contributions to conferences<br />

F. MIRIZZI, PH. BIBET, G. CALABRÒ, V. PERICOLI RIDOLFINI, A.A. TUCCILLO: PAM, MJ and conventional<br />

grills: operative experience on FTU<br />

24 th Symposium on Fusion Technology (SOFT), Warsaw (Poland), September 11-15, 2006<br />

G.L. RAVERA, C. CASTALDO, R. CESARIO, S. LUPINI, S. PODDA, G.B. RIGHETTI AND FTU TEAM: High<br />

power RF components for IBW experiment on FTU<br />

24 th Symposium on Fusion Technology (SOFT), Warsaw (Poland), September 11-15, 2006<br />

O. TUDISCO, C. MAZZOTTA, M.L. APICELLA, G.G. MAZZITELLI, G. MONARI, G. ROCCHI: Density profile<br />

studies of plasmas with lithium limiter<br />

33 rd EPS Conference on Plasma Physics, Rome (Italy), June 19-23, 2006<br />

C. CASTALDO, R. CESARIO, A. CARDINALI, M. MARINUCCI, P. MICOZZI, L. PANACCIONE, M. ANANIA, S. DI<br />

FLAURO, B. EUSEPI, L. PAJEWSKI, G. SCHETTINI, G. GIRUZZI AND THE JET EFDA CONTRIBUTORS:<br />

Modelling of experiments with ITER-relevant q-profile control at high β N by means of the lower hybrid current drive<br />

33 rd EPS Conference on Plasma Physics, Rome (Italy), June 19-23, 2006<br />

F. ZONCA, S. BRIGUGLIO, L. CHEN, G. FOGACCIA, T.S. HAHM, A.V. MILOVANOV, G. VLAD: Physics of<br />

burning plasmas in toroidal magnetic confinement devices<br />

33 rd EPS Conference on Plasma Physics, Rome (Italy), June 19-23, 2006 (Invited Paper)<br />

B. ESPOSITO, M. RICCI, D. MAROCCO, Y. KASCHUCK: A digital acquisition and elaboration system for<br />

nuclear fast pulse detection<br />

X Pisa 2006 Meeting on Advanced Detectors, La Biodola, Isola d’Elba (Italy), May 21-27, 2006<br />

O. TUDISCO, G. GROSSETTI, C. SOZZI: Oblique ECE diagnostic on FTU<br />

14 th Joint Workshop on “Electron Cyclotron Emission and Electron Cyclotron Resonance Heating,<br />

Santorini Island (Greece), May 9-12, 2006<br />

A. CARDINALI, B. ESPOSITO, F. RIMINI, M. BRAMBILLA, F. CRISANTI, M. DE BAAR, E. DE LA LUNA, P.<br />

DE VRIES, X. GARBERT, G. GIROUD, E. JOFFRIN, P. JOFFRIN, P. MANTICA, M. MANTSINEN, A. SALMI,<br />

C. SOZZI, D. VAN EESTER AND JET EFDA CONTRIBUTORS: Modeling and analysis of the ICRH heating<br />

experiments in JET ITB regimes<br />

33 rd EPS Conference on Plasma Physics, Rome (Italy), June 19-23, 2006<br />

M.L. APICELLA, G. MAZZITELLI, V. PERICOLI-RIDOLFINI, V. LAZAREV, A. ALEKSEYEV, A. VERTKOV, R.<br />

ZAGÒRSKI AND FTU TEAM: First experiments with lithium limiter on FTU<br />

17 th Conference on Plasma Surface Interactions (PSI), Hefei Anhui (China), May 22-26, 2006<br />

Progress Report 2006<br />

82


G. MADDALUNO, G. GIACOMI, A. RUFOLONI, L. VERDINI: Tungsten macrobrush sample exposure in FTU tokamak<br />

17 th Conference on Plasma Surface Interactions (PSI), Hefei Anhui (China), May 22-26, 2006<br />

V. MASSAUT, L. DI PACE, L. OOMS, K. BRODÉN, R.A. FORREST, M. ZUCCHETTI: The role of clearance in the<br />

management of future fusion reactor radioactive materials<br />

4 th Symposium Release of Radioactive Material from Regulatory Control, “Harmonisation of Clearance Levels and<br />

Release procedures”, Hamburg (Germany), March 20-22, 2006<br />

S. TOSTI, A. BASILE, F. BORGOGNONI, L. BETTINALI, C. RIZZELLO: Pd membrane reactor design<br />

Euromembrane 2006, Taormina (Italy), September 24-28, 2006<br />

U. DE ANGELIS, G. CAPOBIANCO, C. MARMOLINO, C. CASTALDO: Fluctuations in dusty plasmas<br />

33 rd EPS Conference on Plasma Physic, Rome (Italy), June 19-23, 2006 (Invited Paper)<br />

V. PERICOLI-RIDOLFINI, A. ALEKSEYEV, B. ANGELINI, S.V. ANNIBALDI, M.L. APICELLA, G. APRUZZESE, E.<br />

BARBATO, J. BERRINO, A. BERTOCCHI, W. BIN, F. BOMBARDA, G. BRACCO, A. BRUSCHI, P. BURATTI, G.<br />

CALABRÒ, A. CARDINALI, L. CARRARO, C. CASTALDO, C. CENTIOLI, R. CESARIO, S. CIRANT, V. COCILOVO,<br />

F. CRISANTI, G. D’ANTONA, R. DE ANGELIS, M. DE BENEDETTI, F. DE MARCO, B. ESPOSITO, D. FRIGIONE, L.<br />

GABELLIERI, F. GANDINI, E. GIOVANNOZZI, G. GRANUCCI, F. GRAVANTI, G. GROSSETTI, G. GROSSO, F.<br />

IANNONE, H. KROEGLER, V. LAZAREV, E. LAZZARO, M. LEIGHEB, L. LUBYAKO , G. MADDALUNO, M.<br />

MARINUCCI, D. MAROCCO, J.R. MARTIN-SOLIS , G. MAZZITELLI, C. MAZZOTTA, V. MELLERA, F. MIRIZZI, G.<br />

MONARI, A. MORO, V. MUZZINI, S. NOWAK, F. ORSITTO, L. PANACCIONE, M. PANELLA, L. PIERONI, S.<br />

PODDA, M. E. PUIATTI, G. RAVERA, G. REGNOLI, F. ROMANELLI, M. ROMANELLI, A. SHALASHOV, A.<br />

SIMONETTO, P. SMEULDERS, C. SOZZI, E. STERNINI, U. TARTARI, B. TILIA, A.A. TUCCILLO, O. TUDISCO, M.<br />

VALISA, A. VERTKOV , V. VITALE, G. VLAD, R. ZAGÓRSKI , F. ZONCA: Overview of the FTU results<br />

21 st IAEA Conference on Fusion Energy, Chengdu (China), October 16-22, 2006<br />

G. MAZZITELLI, M.L. APICELLA, C. MAZZOTTA, V. PERICOLI RIDOLFINI. O. TUDISCO, V. LAZAREV, A.<br />

ALEKSEYEV, A. VERTKOV, R. ZAGORSKI, AND FTU TEAM: Lithium as a liquid limiter in FTU<br />

21 st IAEA Conference on Fusion Energy, Chengdu (China), October 16-22, 2006<br />

L. CHEN, F. ZONCA: Nonlinear equilibria, stability and generation of zonal structures in toroidal plasmas<br />

21 st IAEA Conference on Fusion Energy, Chengdu (China), October 16-22, 2006<br />

L. CHEN, F. ZONCA: Theory of Alfvén waves and energetic particle physics in burning plasmas<br />

21 st IAEA Conference on Fusion Energy, Chengdu (China), October 16-22, 2006<br />

F.P. ORSITTO, J–M. NOTERDAEME, A.E. COSTLEY, A.J. DONNÉ AND ITPA TG ON DIAGNOSTICS: Requirements<br />

for fast particle measurements on ITER and candidate measurement techniques<br />

21 st IAEA Conference on Fusion Energy, Chengdu (China), October 16-22, 2006<br />

F. CRISANTI, A. BECOULET, P. BURATTI, E. GIOVANNOZZI, C. GORMEZANO, E. JOFFRIN, A. SIPS, C.<br />

BOURDELLE, A. CARDINALI, C. CHALLIS, N. HAWKES, J. HOBIRK, X. LITAUDON, G. REGNOLI, M. ROMANELLI,<br />

A. THYAGARAJA, A. TUCCILLO, AND JET EFDA CONTRIBUTORS: JET hybrid scenarios with improved core<br />

confinement<br />

21 st IAEA Conference on Fusion Energy, Chengdu (China), October 16-22, 2006<br />

G. VLAD, S. BRIGUGLIO, G. FOGACCIA, K. SHINOHARA, M. ISHIKAWA, M. TAKECHI, F. ZONCA: Particle<br />

simulation analysis of energetic-particle and Alfvén-mode dynamics in JT-60U discharges<br />

21 st IAEA Conference on Fusion Energy, Chengdu (China), October 16-22, 2006<br />

F. ZONCA, P. BURATTI, A. CARDINALI, L. CHEN, J.–Q. DONG, Y.–X. LONG, A. MILOVANOV, F. ROMANELLI, P.<br />

SMEULDERS, L. WANG, Z.–T. WANG: Electron fishbones: theory and experimental evidence<br />

21 st IAEA Conference on Fusion Energy, Chengdu (China), October 16-22, 2006<br />

83<br />

Progress Report 2006


A6 Publications, Patents and Events<br />

V. PERICOLI-RIDOLFINI, M. L. APICELLA, G. MAZZITELLI, O. TUDISCO, R. ZAGÓRSKI AND FTU TEAM:<br />

Edge properties with the liquid lithium limiter in FTU – experiment and transport modelling<br />

Workshop on Edge Transport in Fusion Plasmas (ETFP), Cracovia (Poland), September 11-13, 2006<br />

A Fusion Programme<br />

V. PERICOLI–RIDOLFINI, P. BURATTI, G. CALABRÒ, M. DE BENEDETTI, B. ESPOSITO, L. GABELLIERI, G.<br />

GRANUCCI, M. LEIGHEB, M. MARINUCCI, D. MAROCCO, C. MAZZOTTA, F. MIRIZZI, S. NOWAK, L.<br />

PANACCIONE, G. REGNOLI, M. ROMANELLI, P. SMEULDERS, C. SOZZI, O. TUDISCO, A.A. TUCCILLO:<br />

Internal transport barriers in FTU at ITER relevant plasma density with pure electron heating and current drive<br />

21 st IAEA Conference on Fusion Energy, Chengdu (China), October 16-22, 2006<br />

A. CARDINALI, F. ROMANELLI: Simulation of burning plasma dynamics by ICRH accelerated minority ions<br />

21 st IAEA Conference on Fusion Energy, Chengdu (China), October 16-22, 2006<br />

A. BERTOCCHI, C. CENTIOLI, M. DI DONNA, F. IANNONE, M. PANELLA, L. PANGIONE, V. VITALE, L.<br />

ZACCARIAN: The new FTU continuous monitoring system with Mac OS X technologies<br />

Apple WWDC06 Conference, San Francisco (USA), August 7-11, 2006<br />

G. VLAD, S. BRIGUGLIO, G. FOGACCIA, F. ZONCA: Interaction of fast particles and Alfvén modes in<br />

burning plasmas<br />

Joint Varenna-Lausanne International Workshop on Theory of Fusion Plasmas, Villa Monastero, Varenna<br />

(Italy), August 28 - September 1, 2006<br />

V. GALLUZZI, A. AUGIERI, L. CIONTEA, G. CELENTANO, F. FABBRI, U. GAMBARDELLA, A. MANCINI, T.<br />

PETRISOR, N. POMPEO, A. RUFOLONI, E. SILVA, A. VANNOZZI: YBCO films with BZO inclusions for<br />

strong-pinning in superconducting films on single crystal substrate<br />

Applied Superconductivity Conference (ASC 2006), Seattle WA (USA), August 28 - Setpember 1, 2006<br />

S. TOSTI, L. BETTINALI: Volumes measurement by means of membranes<br />

Euromembrane 2006, Taormina (Italy), September 24-28, 2006<br />

A. VANNOZZI, A. AUGIERI, G. CELENTANO, F. FABBRI, V. GALLUZZI, U. GAMBARDELLA, A. MANCINI, T.<br />

PETRISOR, A. RUFOLONI: Cube textured substrates for YBCO coated conductors: influence of initial grain<br />

size and strain conditions during tape rolling<br />

Applied Superconductivity Conference (ASC 2006), Seattle WA (USA), August 28 - Setpember 1, 2006<br />

A. CARDINALI, L. MORINI, F. ZONCA: Analysis of the validity of the asymptotic techniques in the lower<br />

hybrid wave equation solution for reactor aplications<br />

Joint Varenna-Lausanne International Workshop on Theory of Fusion Plasmas, Villa Monastero, Varenna<br />

(Italy), August 28 - September 1, 2006<br />

A. BERTOCCHI, M. DI DONNA, M. PANELLA, V. VITALE: The liquid lithium limiter control system on FTU<br />

24 th Symposium on Fusion Technology (SOFT), Warsaw (Poland), September 11-15, 2006<br />

V. VITALE, C. CENTIOLI, F. IANNONE, M. PANELLA, L. PANGIONE, M. SABATINI, L. ZACCARIAN, R.<br />

ZUCCALÀ: SA matlab based framework for the real-time environment at FTU<br />

24 th Symposium on Fusion Technology (SOFT), Warsaw (Poland), September 11-15, 2006<br />

V. MASSAUT, R. BESTWICK, K. BRODEN, L. DI PACE, L. OOMS, R. PAMPIN: State of the art of fusion<br />

material recycling and remaining issues<br />

24 th Symposium on Fusion Technology (SOFT), Warsaw (Poland), September 11-15, 2006<br />

M. ANGELONE, L. PETRIZZI, M. PILLON, S. POPOVICHEV, R. VILLARI: Dose rate experiment at JET for<br />

benchmarking the calculation direct one step method<br />

24th Symposium on Fusion Technology (SOFT), Warsaw (Poland), September 11-15, 2006<br />

Progress Report 2006<br />

84


C. NERI, L. BARTOLINI, M. FERRI DE COLLIBUS, G. FORNETTI, F. POLLASTRONE, M. RIVA, L. SEMERARO: The<br />

laser in vessel viewing system (IVVS) for ITER: test results on first wall and divertor samples and new developments<br />

24 th Symposium on Fusion Technology (SOFT), Warsaw (Poland), September 11-15, 2006<br />

L. DI PACE, T. PINNA: Assessment of occupational radiation exposure (ORE) for hands-on assistance to the<br />

remote handling at ITER ports and waste treatment<br />

24 th Symposium on Fusion Technology (SOFT), Warsaw (Poland), September 11-15, 2006<br />

M. SANTINELLI, R. CLAESEN, A. COLETTI. T. BONICELLI, P.L. MONDINO, M. PRETELLI, L. RINALDI, L. SITA, G.<br />

TADDIA: Solid state gyrotron body power supply, test results<br />

24th Symposium on Fusion Technology (SOFT), Warsaw (Poland), September 11-15, 2006<br />

P. BATISTONI, M. ANGELONE, L. BETTINALI, P. CARCONI, U. FISCHER, I. KODELI, D. LEICHTLE, K. OCHIAI, R.<br />

PEREL, M. PILLON, I. SCHÄFER, K. SEIDEL, Y. VERZILOV, R. VILLARI, G. ZAPPA: Neutronics experiment on a<br />

HCPB breeder blanket mock-up<br />

24 th Symposium on Fusion Technology (SOFT), Warsaw (Poland), September 11-15, 2006<br />

T. PINNA, G. CAMBI, F. GRAVANTI: Collection and analysis of component failure data from JET systems<br />

8 th IAEA Technical Meeting on “Fusion Power Plant Safety”, Wien (Austria), July 10-13, 2006<br />

F. ALLADIO, P. COSTA, A. MANCUSO, P. MICOZZI, R. AKERS, G. CUNNINGHAM, M. GRYAZNEVICH, M. HOOD,<br />

G. MC ARDLE, V. SHEVCHENKO, A. SYKES, F. VOLPE, A. DNESTROVSKIJ: Status and perspectives of MAST<br />

start-up in the absence of solenoid flux<br />

33 rd EPS Conference on Plasma Physics, Rome (Italy), June 19-23, 2006<br />

G. REGNOLI, M. ROMANELLI, C. BOURDELLE, M. DE BENEDETTI, M. MARINUCCI, V. PERICOLI, G. GRANUCCI, C.<br />

SOZZI, O. TUDISCO, E. GIOVANNOZZI, ECRH, LH AND FTU TEAM: Microstability analysis of collisional plasmas<br />

33 rd EPS Conference on Plasma Physics, Rome (Italy), June 19-23, 2006<br />

E. GIOVANNOZZI, C. CASTALDO, G. MADDALUNO: Evidence of dust in FTU from Thomson scattering diagnostic<br />

measurements<br />

33 rd EPS Conference on Plasma Physics, Rome (Italy), June 19-23, 2006<br />

G. FOGACCIA, S. BRIGUGLIO, M. ISHIKAWA, K. SHINOHARA, M. TAKECHI, G. VLAD, F. ZONCA: Particle<br />

simulations of energetic particle driven Alfvèn modes in JT-60U<br />

33 rd EPS Conference on Plasma Physics, Rome (Italy), June 19-23, 2006<br />

J.R. MARTIN-SOLIS, B. ESPOSITO, R. SANCHEZ, F.M. POLI, L. PANACCIONE: Runaway current plateau<br />

formation during disruptions in the FTU Tokamak<br />

33 rd EPS Conference on Plasma Physics, Rome (Italy), June 19-23, 2006<br />

B. ESPOSITO, G. GRANUCCI, S. NOWAK, P. SMEULDERS, J. BERRINO, J.R. MARTIN-SOLIS, R. SANCHEZ, L.<br />

GABELLIERI, M. LEIGHEB, F. GANDINI, D. MAROCCO, C. MAZZOTTA, O. TUDISCO: Disruption mitigation<br />

experiments in FTU using ECRH<br />

33 rd EPS Conference on Plasma Physics, Rome (Italy), June 19-23, 2006<br />

M. ROMANELLI, G.T. HOANG, C. BOURDELLE, C. GORMEZANO, E. GIOVANNOZZI, M. LEIGHEB, M.<br />

MARINUCCI, D. MAROCCO, C. MAZZOTTA, L. PANACCIONE, V. PERICOLI, G. REGNOLI, O. TUDISCO, AND<br />

THE FTU TEAM: Parametric dependence of turbulent particle transport in high collisionality plasmas on the<br />

Frascati Tokamak Upgrade FTU<br />

33 rd EPS Conference on Plasma Physics, Rome (Italy), June 19-23, 2006<br />

M. ROMANELLI, M. LEIGHEB, L. GABELLIERI, L. CARRARO, M.E. PUIATTI, M. VALISA, M. MATTIOLI, L. LAURO-<br />

TARONI, M. DE BENEDETTI, M. MARINUCCI, C. MAZZOTTA, G. REGNOLI, P. SMEULDERS, S. NOVAK, C.<br />

85<br />

Progress Report 2006


A6 Publications, Patents and Events<br />

SOZZI: Investigation of turbulent transport of heavy impurities in FTU electron heated plasmas<br />

33 rd EPS Conference on Plasma Physics, Rome (Italy), June 19-23, 2006<br />

A Fusion Programme<br />

G. CALABRÒ, V. PERICOLI-RIDOLFINI, L. PANACCIONE AND FTU TEAM: Effect of the scattering from<br />

edge density fluctuations on the lower hybrid waves in FTU<br />

33 rd EPS Conference on Plasma Physics, Rome (Italy), June 19-23, 2006<br />

M. RIVA, B. ESPOSITO, D. MAROCCO: A new pulse-oriented digitial aquisition system for nuclear<br />

detectors<br />

24 th Symposium on Fusion Technology (SOFT), Warsaw (Poland), September 11-15, 2006<br />

M. PILLON. M. ANGELONE, D. LATTANZI, M. MARINELLI, E. MILANI, A. TUCCIARONE, G. VERONA-<br />

RINATI, S. POPOVICHEV, R.M. MONTEREALI, M.A. VINCENTI, A. MURATI AND JET -EFDA<br />

CONTRIBUTORS: Neutron detection at JET using artificial diamond detectors<br />

24 th Symposium on Fusion Technology (SOFT), Warsaw (Poland), September 11-15, 2006<br />

C. CASTALDO, U. DE ANGELIS, V.N. TSYTOVICH: Screening and attraction of dust particles in plasmas<br />

33 rd EPS Conference on Plasma Physics, Rome (Italy), June 19-23, 2006<br />

M.L. APICELLA, M. LEGHEB, M. MARINUCCI, G. MAZZITELLI, FTU TEAM, V. LAZAREV, A. ALEKSEYEV,<br />

A. VERTKOV: Energy balance of FTU discharges with lithizated walls<br />

33 rd EPS Conference on Plasma Physics, Rome (Italy) June 19-23, 2006<br />

S.V. ANNIBALDI, F. ZONCA, P. BURATTI: Excitation of beta-induced Alfvèn eigenmodes in the presence of<br />

a magnetic island<br />

33 rd EPS Conference on Plasma Physics, Rome (Italy), June 19-23, 2006<br />

E. VISCA, S. LIBERA, A. MANCINI, G. MAZZONE, A. PIZZUTO, C. TESTANI: Pre-brazed casting and hot<br />

radial pressing: a reliable process for the manufacturing of CFC and W monoblock mockups<br />

24 th Symposium on Fusion Technology (SOFT), Warsaw (Poland), September 11-15, 2006<br />

Reports<br />

RT/ 2006/35/FUS<br />

RT/2006/69/FPN<br />

RM2006A000429<br />

R. CHIRICO<br />

Studio sui rischi per la sicurezza e per la salute associati all’utilizzo di un limiter di<br />

litio durante le sperimentazioni con FTU (Frascati Tokamak Upgrade)<br />

R. CHIRICO<br />

Teorie e parametrizzazioni per la ripartizione degli IPA su particolato atmosferico:<br />

stato dell’arte<br />

A6.2 Patents<br />

A. DELLA CORTE, A. DI ZENOBIO<br />

Procedimento per la realizzazione di un giunto tra cavi superconduttori di tipo<br />

CICC a basso livello di ingombro, bassa resistenza elettrica e basso costo di<br />

realizzazione<br />

Progress Report 2006<br />

86


RM2006A000314 L. BETTINALI, V. VIOLANTE, F. SARTO, C. SIBILIA, M. BERTOLOTT, E. CASTAGNA, I.<br />

DARDIK, S.LESIN, T. ZILOV, M. TSIRLIN<br />

Materiali laminati metallici con inclusioni di materiale dielettrico per l’amplificazione ed il<br />

controllo del campo elettrico di interfase, e relativo processo di produzione<br />

RM2006A000102<br />

S. TOSTI, D. LECCI, C. RIZZELLO, A. BASILE<br />

Procedimento a membrana per la produzione di idrogeno da reforming di composti<br />

organici, in particolare idrocarburi o alcoli<br />

A6.3 Conferences and Events<br />

June 19-23, 2006<br />

33 rd European Physics Society - Conference on Plasma Physics<br />

Rome (Italy)<br />

A6.4 Seminars<br />

21/03/2006 S. ORTOLANI - Consorzio RFX - <strong>ENEA</strong> - Padova, Italy<br />

Active MHD control experiments in RFX - mod<br />

24/03/2006 J. KASAGI – LNS, Tohoku University - Tohoku, Japan<br />

Low energy nuclear reactions in condensed matter<br />

28/04/2006 S. MIRNOV - TRINITI - Troitsk, Russia<br />

Test of the lithium capillary - pore system (CPS) as tokamak limiter and DEMO perspective of Li CPS<br />

10/07/2006 M. TESSAROTTO - Università di Trieste - Trieste, Italy<br />

Il problema di Debye per plasmi debolmente e fortemente accoppiati<br />

25/09/2006 M. SHOUCRI - IREQ - Varennes, Quebec, Canada<br />

Study of a turbulent spectrum at the edge of a 2D plasma slab in the gyrokinetic approximation<br />

13/12/2006 P. SCARIN - Consorzio RFX - Padova, Italy<br />

Edge turbulence evidence in RFX - mod with GPI diagnostic<br />

13/12/2006 A. SANTUCCI - Università “Tor Vergata” - Roma, Italy<br />

Reforming di etanolo in reattori a membrana<br />

19/12/2006 S. GERASSIMOV - Technical Univ. of Münich and CERN - Münich, Germany<br />

Use of ROOT to store large quantities of scientific data<br />

13/12/2006 V. CAPALDO - Università “La Sapienza” - Roma, Italy<br />

Reforming di etanolo in reattori a membrana<br />

87<br />

Progress Report 2006


B1 R&D on Nuclear Fission<br />

B Fission Technology<br />

B1.1 Innovative Fuel Cycles Including Partitioning and<br />

Transmutation<br />

Activities on partition and transmutation started under the 5 th European Framework Programme<br />

(FP5) and have continued under FP6. The work on chemical partitioning was carried out under the<br />

European Research Programme for the Partitioning of Minor Actinides (EUROPART) concerning the<br />

partitioning of long-lived radionuclides (LLRNs) contained in the nuclear waste resulting from the<br />

reprocessing of spent nuclear fuel. After separation, the LLRNs will be destroyed by nuclear means<br />

so as to become short-lived or stable nuclides or conditioned into stable dedicated solid matrices.<br />

Transmutation activities were carried out under the European Transmutation (EUROTRANS) project<br />

submitted by <strong>ENEA</strong>, Commissariat à l’Energie Atomique (CEA), Forschungszentrum Karlsruhe (FZK)<br />

and the Belgian Nuclear Research Centre (SCK-CEN). The objectives are to demonstrate<br />

experimentally the accelerator driven system (ADS) operations and dynamic characteristics and then<br />

to deliver a conceptual design for a European Transmutator Demonstrator (ETD), including its overall<br />

technical feasibility, and to perform an economic assessment.<br />

<strong>ENEA</strong> coordinates the European Virtual European Lead Initiative (VELLA) project, which has the<br />

ambitious intent to homogenize the European research area in the field of leading technologies for<br />

nuclear applications in order to produce a common platform of work that will continue also after the<br />

end of the initiative. The issues of this activity are also of interest to evolutionary and innovative<br />

reactor activities (see B1.2).<br />

Studies on innovative uranium-free inert matrix and thorium fuels, aimed at in-reactor plutonium<br />

incineration either in the current light-water reactors (LWRs) or in next-generation reactors, were<br />

continued in 2006. <strong>ENEA</strong> researchers participated in a first evaluation of the experimental data from<br />

the IFA-652 irradiation test performed up to the end of 2005 in the Halden Material Test Reactor<br />

(Norway). A good response of the proposed fuel concept was found, with an under-irradiation<br />

stability similar to that of UOX and MOX fuels, except for a somewhat higher fission gas release<br />

(FGR) rate. In parallel, implementation of the inert matrix fuel (IMF) basic thermo-physical properties<br />

and models on the fuel-rod performance code Transuranus was completed and a simulation of the<br />

first-phase of IFA-652 irradiation in Halden was performed. Preliminary modelling with Transuranus<br />

on CER-CER and CER-MET fuels for transmutation, started in 2005, was also continued.<br />

Dispersion of the fissile phase based on Pu and MAs oxides in Mg oxide matrix (CER-CER) or in<br />

molybdenum metal matrix (CER-MET) was considered in the study.<br />

Partitioning technology<br />

The principal operation of chemical partitioning (fig. B1.1, [B1.1]) is electrorefining, which takes place<br />

in an electrochemical cell where dissolution of most of the fuel elements occurs. This is followed by<br />

selective electrodeposition of the actinides onto a solid and/or a liquid cathode through application<br />

Progress Report 2006<br />

88


Spent<br />

fuel<br />

Disassembly<br />

and<br />

chopping<br />

Duct Clad, N M<br />

Melting<br />

Consolidation<br />

Metal waste<br />

Gas waste (T,Xe,Kr)<br />

Electrorefining<br />

Spent<br />

salt<br />

TRU<br />

extraction<br />

TRU<br />

Immobilisation<br />

Salt waste (Cs,Sr,RE)<br />

Salt, Cd<br />

U, salt<br />

U-TRU<br />

-CD-salt<br />

Cathode<br />

processing<br />

Crucible<br />

of an electrochemical<br />

difference among elements<br />

in molten LiCl-KCl salt and<br />

liquid cadmium (or<br />

bismuth) under a highpurity<br />

argon atmosphere at<br />

773 K (pyro processing).<br />

The ex perimental<br />

campaigns concerned<br />

electrorefining experiments<br />

with the Pyrel II plant and<br />

conditioning of chloride salt wastes arising from pyroprocessing of spent nuclear fuel.<br />

Experimental campaigns. The Pyrel II facility [B1.2] was used to study the behaviour of lanthanum and<br />

cerium loaded on different anodes and electrotransported to different cathodes. The current was varied<br />

whenever possible and both salt and metal phases were sampled. Seven experiments were performed:<br />

direct transportation from fuel dissolution basket (FDB) to solid steel cathode (SSC); anodic dissolution<br />

(from FDB to Bi pool); transportation from FDB to liquid bismuth cathode (LBC); direct (chemical)<br />

dissolution; transportation from Bi pool to SSC; transportation from Bi pool to LBC; salt clean-up between<br />

Bi-Li anode and SSC.<br />

Full evaluation of the results obtained is not easy at this stage, but a few considerations can be made:<br />

• A cathode deposit is practically absent in any case.<br />

• The electric current can be imposed only to a maximum specific value, depending on the type of<br />

experiment.<br />

• The fuel dissolution basket extracted from the salt bath after the experiments with La ingots shows that<br />

La is still present in the FDB.<br />

• Salt clean-up allows a significant amount of residual elements to be removed from the salt bath, with<br />

the metals deposited at the Bi-Li anode, mainly around the magnesia vessel.<br />

A real puzzle is the concentration of La and Ce in the chloride salt. It can be supposed that something<br />

other than the electric current is involved in the process. Clarification of the above and other important<br />

questions is mandatory for complete com prehension of<br />

the phenomena which take place during the<br />

2000<br />

electrorefining experiments with Pyrel II, and for the<br />

project of a new plant (Pyrel III) designed for<br />

electrorefining with uranium ingots.<br />

1000<br />

Chloride waste treatment. The pyrochemical<br />

process produces a salt waste containing Li, K, and FP<br />

chlorides, which after several batches accumulate in<br />

the molten salt media and represent an environmental<br />

concern because of their high water solubility. Sodalite,<br />

a naturally occurring mineral, is a major candidate for<br />

conditioning salt waste as it can incorporate chloride<br />

metals in its cage-like structure. Hence pure sodalite<br />

was prepared for use as reference material.<br />

Zr<br />

TRU: Pu, Np, Am, Cm<br />

RE: Rare earth<br />

NM: Noble metal<br />

New<br />

fuel<br />

Pin<br />

casting<br />

Mold<br />

crucible<br />

Counts/s<br />

Fig. B1.1 – General schematic of spent<br />

fuel reprocessing by pyrochemical<br />

electrorefining (redrawn from ref. B1.1)<br />

0<br />

10 30 50 70 90<br />

2θ<br />

Fig. B1.2 – X-ray diffraction spectrum related to the<br />

formation of sodalite from chloride salt, silica and sodium<br />

aluminate after 50 h of reaction<br />

[B1.1] T. Nishimura et al., Progr. Nucl. Energy 32, 3/4, 381-387 (1998)<br />

[B1.2] G. De Angelis and E. Baicchi, A new electrolyzer for pyrochemical process studies, Presented at the GLOBAL 2005 (Tsukuba 2005)<br />

References<br />

89<br />

Progress Report 2006


B1 R&D on Nuclear Fission<br />

B Fission Technology<br />

zos04<br />

zos03<br />

zos02<br />

zos01<br />

zeolite A<br />

10 20 30 40 50 60 70<br />

2θ<br />

Time<br />

Fig. B1.3 – X-ray diffraction spectra related to the<br />

formation of sodalite starting from zeolite A, at increasing<br />

reaction times<br />

Tests performed to prepare the sodalite<br />

starting from silica and sodium aluminate<br />

(fig. B1.2) or from zeolite A (fig. B1.3) show<br />

the formation of an intermediate phase,<br />

nepheline, which is known to be more<br />

leachable with respect to other phases, like<br />

sodalite or pollucite. The role of microwaves<br />

and their effect on the reaction yield were also<br />

studied. Two different heating methods (inside<br />

a microwave oven or in a tubular oven) proved<br />

successful, even if the reaction conditions as<br />

well as the starting materials need a clear<br />

definition. The demonstration that the same<br />

intermediate compound (nepheline) is present<br />

in the synthesis of sodalite irrespective of the<br />

method used was a success in itself.<br />

The next step should be the synthesis of pure sodalite and localisation of the position of the various<br />

cations inside the crystal lattice. While Li, Na, and K are presumably included in the structure of<br />

sodalite, it is more difficult to identify the relative positions of ions such as Cs, Sr and Ba.<br />

Transmutation systems and related technology<br />

Research on transmutation was mainly focussed on:<br />

• Neutronic design of a Pb-cooled European facility on an industrial-scale transmuter (EFIT – the<br />

European Facility for Industrial Transmutation) (Domain Design).<br />

• Study of the energetic gain expected in the Reactor-Accelerator Coupling Experiment (RACE)<br />

and on a new neutron detector for characterisation of the neutron spectrum in subcritical devices<br />

(Domain ECATS).<br />

• Experimental activities to study the interaction between lead bismuth eutectic (LBE) and water<br />

consequent to heavy leaks due to a cooling tube rupture inside the steam generator and on a<br />

large-scale integral test (Domain DEMETRA).<br />

EFIT core design criteria: the “42-0” approach. Work concerned the neutronic analysis of the<br />

EFIT sub-critical reactor, in particular the preliminary definition of the core and fuel subassembly<br />

(S/A). Experience gained through the ANSALDO-<strong>ENEA</strong> collaboration in the Preliminary Design Study<br />

– Experimental Accelerator Driven System (PDS-XADS) project, a 80-MW th core cooled by LBE<br />

[B1.3], was exploited as far as possible. However, since the fuel (uranium-free, fig. B1.4a)) as well<br />

as the goal of maximum rate minor-actinide (MA: Np, Cm, Am) burning are quite different from the<br />

PDS-XADS, an innovative approach was developed to deal with the core design and fuel cycle,<br />

mainly aimed at minimising the cost per kg of MAs burnt. Hence, a twofold strategy was assumed<br />

[B1.4]:<br />

1. The so called “42-0” approach, i.e., the invariant 42 kg of fissioned material per TWh th have to<br />

be MAs, whilst Pu is neither burnt (since it would be of low value in sub-critical reactors) nor bred<br />

(since this would be inconsistent with the uranium-free choice) and acts as a “catalyser”. This<br />

univocally leads to fuel enrichment at about 45.7% in Pu, which represents the main starting<br />

parameter of the EFIT core design. In fact the K eff swing over the fuel cycle (which also mainly<br />

depends on the fuel enrichment) has to be compatible with the proton accelerator performance.<br />

2. The core size has to be optimised to obtain the minimum cost per fissioned kg of MAs. Since the<br />

burning rate per TWh th does not depend on the core size, the optimisation criterion (in the 42-0<br />

approach) becomes the minimum cost of the deployed power unit. Actually, the reactor unitary<br />

cost decreases with core size (in a certain range), whilst the accelerator cost is likely to increase,<br />

Progress Report 2006<br />

90


mainly due to the loss of source<br />

efficiency. As the information<br />

needed for a possible trade-off<br />

was missing, it was decided to<br />

assume the largest core<br />

compatible with the present<br />

design of the spallation module,<br />

as a simplified criterion.<br />

The ANSALDO-develop ed [B1.4]<br />

800-MeV/20 mA spallation module<br />

which can evacuate 11.2 MW of<br />

power (70% of the total beam<br />

power) was assumed as reference.<br />

The target is a windowless type (as<br />

in PDS-XADS [B1.3]) with a<br />

horizontal coolant flow in the<br />

spallation region, mechanical<br />

pumps and a heat sink below the<br />

Pb free surface level. At room<br />

temperature the circular target has<br />

Pu<br />

Pu238<br />

Pu239<br />

Pu240<br />

Pu241<br />

Pu242<br />

Pu244<br />

Pu238<br />

Pu239<br />

Pu240<br />

Pu241<br />

Pu242<br />

Pu244<br />

(w%)<br />

3.737<br />

46.446<br />

34.121<br />

3.845<br />

11.850<br />

0.001<br />

an outer diameter of 782 mm: hosting it by replacing 19 S/As,<br />

the fuel assembly (FA) wrapper flat to flat external distance is<br />

186 mm (191 mm by considering the clearance between FAs).<br />

In addition, the spallation module size together with the<br />

maximum proton current (20 mA), the selected sub-criticality<br />

level (K eff =0.97) and the maximum allowable linear power<br />

(P L ≅200 [W cm -1 ]) give as output the core size and the overall<br />

power (P th ).<br />

Figure B1.4a) shows the adopted fuel isotopic composition (Pu<br />

and MA vectors), which comes from a reprocessed MOX spent<br />

fuel, irradiated at 60 GWd t -1 (i.e., 30 years [B1.5]) and after a<br />

30–year ageing. The PuO 2 and MAO 2 were inserted in a<br />

magnesium-oxide (MgO) matrix with different volume<br />

Pu & MA isotopic compositions<br />

MOX spent fuel after 30 years’ cooling (CEA)<br />

Pu vector<br />

Ma vector<br />

91.8% Am<br />

Np237<br />

4.3% Cm<br />

Am241<br />

Am242<br />

Am242m<br />

Am243<br />

Cm242<br />

Cm243<br />

Cm244<br />

Cm245<br />

Cm246<br />

Cm247<br />

Cm248<br />

percentages in order to flatten the radial performances by using the same fuel enrichment in the whole<br />

core.<br />

Since a high MA content was assumed, particular attention was also devoted to the safety aspects. By<br />

adopting a stochastic approach, it was demonstrated that similar uranium-free fuels, with cross-section vs<br />

energy behaviour similar to that in figure B1.4b), are characterised by:<br />

• “deterioration” of the delayed neutron effective fraction and kinetic parameters;<br />

• lack of Doppler prompt reactivity feedback;<br />

• deterioration of the void effect such that it does not guarantee in any case the desired sub-criticality<br />

level.<br />

Cross section (barns)<br />

MA<br />

Np237<br />

Am241<br />

Am242<br />

Am242m<br />

Am243<br />

Cm242<br />

Cm243<br />

Cm244<br />

Cm245<br />

Cm246<br />

Cm247<br />

Cm248<br />

(w%)<br />

3.884<br />

75.510<br />

3.27E-06<br />

0.254<br />

16.054<br />

2.37E-20<br />

0.066<br />

3.001<br />

1.139<br />

0.089<br />

0.002<br />

1.01E-04<br />

10 5<br />

10 4<br />

b)<br />

elastic scattering<br />

1000<br />

100<br />

10<br />

1<br />

0.1<br />

0.01<br />

0.001<br />

10 -4<br />

fission<br />

capture<br />

10 -10 10 -8 10 -6 10 -4 10 -2 1 100<br />

Energy (MeV)<br />

Fig. B1.4 – a) Pu and MA vectors; b) capture, elastic<br />

scattering and fission cross sections (from MCNPX code<br />

and JEFF 3.1 neutron cross sections)<br />

a)<br />

[B1.3]<br />

[B1.4]<br />

[B1.5]<br />

XADS 41 SNPX 042, Core configuration technical specification of the LBE-cooled XADS, Contractual Deliverable n° D10 FIKW-CT-2001-<br />

00179, Technical Report Ansaldo Energia (2001)<br />

Specialist Meetings on the Pb-EFIT core design, INPN Orsay – Paris, 24-25 October 2005; <strong>ENEA</strong> - Bologna, 22-23 February 2006; CEA<br />

Cadarache, 9-10 March 2006; CEA Cadarache, 13-14 June 2006<br />

G. Rimpault, Definition of the detailed missions of both the Pb-Bi cooled XT-ADS and Pb cooled EFIT and its gas back-up option,<br />

Technical Report CEA SPRC/LEDC 05-420 (2005); and IP EUROTRANS – DM1 Design – WP 1.1 – Deliverable 1.1, Contract n° FI6W-<br />

CT-2004-516520 (2006)<br />

References<br />

91<br />

Progress Report 2006


45<br />

B1 R&D on Nuclear Fission<br />

B Fission Technology<br />

0.6<br />

7.2 mm<br />

7.52 mm<br />

8.72 mm<br />

Fuel<br />

Void<br />

SS<br />

Pb<br />

PD Hom (W cm -3 )<br />

0.16<br />

Fuel inner<br />

62.5% MgO<br />

115<br />

13.63 mm<br />

4.91 mm<br />

VF(Fuel pellet)=21.65%<br />

Filling ρ = 0.9167<br />

(750°C)<br />

(480°C)<br />

(440°C)<br />

Fuel outer<br />

50% MgO<br />

ff rad =1.29<br />

ff ax =1.14<br />

191 mm<br />

186 mm<br />

178 mm<br />

168+1 Fuel pins<br />

(7+1 pin rows)<br />

b)<br />

a)<br />

a)<br />

EFIT two-zone model. A 395-MW th<br />

reference core with two radial zones,<br />

surrounded by dummy reflector elements in<br />

Pb (fig. B1.5a)) was designed, and its<br />

transmutation capability and overall core<br />

performance were checked. To achieve this<br />

configuration, while the active height (90 cm,<br />

to limit the pressure drop) and the ΔT core (400-<br />

480°C) were maintained fixed, the reactor<br />

radial dimension (i.e., the number of FAs) and<br />

the MgO volumetric fraction (VF) were varied<br />

to flatten the core radial performance, at the<br />

same time keeping the condition K eff ≤0.97<br />

over the cycle.<br />

95<br />

This two-zone solution was analysed by a<br />

ff rad =1.45<br />

ff ax =1.15<br />

cylindrical geometry model (fig. B1.5b)) in<br />

75<br />

which the different radii were assumed<br />

Max INN (BOC)<br />

equivalent to a certain number of FAs.<br />

55 Max OUT (BOC)<br />

Max INN (EOC)<br />

Neutronic analysis was carried out with the<br />

Max OUT (EOC)<br />

ERANOS version 2.0 deterministic code [B1.6]<br />

35<br />

40 80 120 160 and the ERALIB1 nuclear data library [B1.7].<br />

R (cm)<br />

The spatial and energy distributions of the<br />

external neutron source, generated by the<br />

Fig. B1.6 – 395 MW th EFIT two-zone model: a) inner and spallation process of the 800-MeV protons<br />

outer FA design; b) PD radial profiles at about half active impinging on the Pb windowless target, were<br />

height (BOC and EOC)<br />

obtained by Monte Carlo methods (Monte<br />

Carlo N-particle transport code [B1.8]). The<br />

angular distribution of the source neutrons was assumed isotropic in the laboratory frame.<br />

The EFIT two-zone model (fig. B1.5) exhibits a suitable radial power distribution by using MgO VFs<br />

of 62.5% and 50% (lowest MgO technological content) in the inner (48 FAs) and outer (174 FAs) fuel<br />

zones, respectively. Figure B1.6a) shows the geometrical characteristics of the FAs with 168 fuel<br />

pins and the 21.65% fuel VF. The 395 MW th power was reached by imposing the max P L (which<br />

really depends on the MgO VF and the related pellet conductivity) at 213 and 180 [W cm -1 ] in the<br />

inner and outer zones, respectively. Figure B1.6b) shows the power density (PD) radial distributions<br />

330<br />

265<br />

215<br />

185<br />

170<br />

140<br />

125<br />

75<br />

Z (cm)<br />

Beam line<br />

15<br />

Target<br />

Internal lead<br />

R t = 43.7<br />

Top assembly<br />

Plenum<br />

Fuel inner<br />

Plenum<br />

ΔR<br />

Fuel outer<br />

50<br />

50<br />

ΔR 1<br />

ΔR 2<br />

Foot assembly<br />

90<br />

Box<br />

dummy<br />

Fig. B1.5 – 395 MW th EFIT two-zone model: a) hexagonal layout; b) cylindrical model<br />

Pb Ext<br />

200 252<br />

b)<br />

R (cm)<br />

Progress Report 2006<br />

92


on the homogenised core (at about half of the active<br />

height where PD reaches maximum values). The orange<br />

and red horizontal lines, which correspond to the<br />

technological limits on the max P L , indicate that both at<br />

the first and at the second year of irradiation<br />

(corresponding to the beginning of cycle [BOC] and end<br />

of cycle [EOC]) the safety limits are not exceeded. Figure<br />

B1.6b) also shows the radial and axial form factor values<br />

(ff rad and ff ax ), corresponding to the worst condition<br />

(BOC, lowest K eff value).<br />

The resulting sub-critical core exhibits very satisfactory<br />

performance, since it has a very small K eff swing over the<br />

cycle limited to about 200 pcm (fig. B1.7a)), requiring a<br />

roughly constant proton current that never exceeds<br />

16.3 mA.<br />

As for the in-pile fuel cycle, a three-year maximum<br />

residence time was assumed, due to Pb corrosion<br />

constraint. Considering a refuelling pattern of 1/3 of the<br />

core each year, some “ad hoc” hypotheses permit<br />

burn–up calculations to be performed without any actual<br />

refuelling, as follows:<br />

kg K eff<br />

0.975<br />

0.973<br />

0.971<br />

BOL BOC EOC EOL<br />

0.969<br />

0 1 2 3<br />

3100<br />

2900<br />

2700<br />

ΔK eff swing<br />

≅ 200 pcm<br />

Tot Pu<br />

b)<br />

Tot MA<br />

ΔMA/MA (BOL) = -12.95%<br />

ΔPu/Pu (BOL) = -0.25%<br />

2500<br />

0 1 2 3<br />

Time (years)<br />

Fig. B1.7 – a) K eff (t) behaviour; b) absolute and relative<br />

MAs and Pu burn-up performance<br />

a)<br />

• For the core performance it is sufficient to consider the reactor conditions at the first year (BOC) and at<br />

the second year (EOC) of irradiation.<br />

• For the transmutation performance, the third year of irradiation was considered as FA end of life (EOL).<br />

Figure B1.7b) shows the burn-up capability (with the 45.7% fuel enrichment). By considering the mass<br />

balances at the third year of irradiation (FA EOL), a relative MA and Pu burn-up of about 13% and 0.25%,<br />

respectively, was obtained. The transmutation obtained for the MA and Pu isotopes is 40.6 and<br />

0.7 [kg TWh th -1 ], respectively, which is almost in agreement with the 42-0 approach.<br />

The main drawback of this two-zone core is the too high ff rad value in the outer part (1.45; fig. B1.6b)): a<br />

RELAP thermohydraulic analysis [B1.9] showed that the limit on the maximum cladding temperature<br />

(550°C) is reached in this zone. This is a consequence of the small difference between the Pb outlet<br />

(480°C) and the maximum cladding temperatures allowed, which imposes working with very limited ff rad .<br />

To avoid having a lot of different SA orifices, a core with three radial zones was considered. However the<br />

main result is that the 42-0 approach for MA transmutation in a sub-critical system (without Pu burning and<br />

production) is a viable strategy because the resulting K eff (t) swing (which depends on the fuel enrichment)<br />

is compatible with a reasonable proton accelerator current range.<br />

Reactivity worth, decay heat and fuel equilibrium analyses. The uranium-free choice (with high MA<br />

content) is characterised by a lack of the Doppler effect, a low delayed neutron fraction and deterioration<br />

of the coolant void effect (fig. B1.8a)). These results, obtained by MCNP [B1.8], suggest that some<br />

[B1.6] G. Rimpault et al., Schema de calcul de reference du formulaire eranos et orientations pour le schema de calcul de projet, CEA<br />

XT–SBD–0001 (1997)<br />

[B1.7] E. Fort et al., Application a la realisation de ERALIB1, bibliotheque de donnes neutroniques pour le calcul des systems a spectre rapide,<br />

Technical Report CEA SPRC/LEPh 97-002 (1997)<br />

[B1.8] J.S. Hendricks et al., MCNPX Version 2.5.B, LA-UR-02-7086 (2002)<br />

[B1.9] C.D. Fletcher and R.R. Schultz, Relap5/Mod3 Code Manual – User’s Guidelines, Vol. 5, Idaho National Engineering Laboratory;<br />

NURG/CR-55 EGG-2596 (1992)<br />

References<br />

93<br />

Progress Report 2006


B1 R&D on Nuclear Fission<br />

B Fission Technology<br />

Void effect total reactivity<br />

worth per ring (pcm)<br />

3000<br />

2000<br />

1000<br />

0<br />

-500<br />

Cadarache meeting<br />

core solution<br />

Bologna meeting<br />

core solution<br />

1 2 3 4 5 6<br />

Ring<br />

2000<br />

50%PU 50% MA-origen2<br />

a) b)<br />

113<br />

22<br />

MOX-origen2<br />

MOX-fispact<br />

30%PU 70% MA-fispact<br />

30%PU 70% MA-origen2<br />

50%PU 50%MA-fispact<br />

neutronic design assumptions as well as the expected core performance should be reconsidered,<br />

mainly from the safety viewpoint.<br />

The decay heat problem deriving from the massive use of MAs [B1.10, B1.11] was also studied in<br />

detail [B1.4, B1.12]. Compared to the standard MOX fuels, AnOx fuel has a higher decay heat rate,<br />

the decay heat decreases less in time and is higher (by up to ∼45 times). Figure B1.8b) shows<br />

performance and behaviour vs decay time for uranium-free fuel. From the reactor design viewpoint,<br />

an important aspect is the long-term reliability of the decay-heat-removal components.<br />

Finally the question of core (re)fuelling only by MA fuels, independently of the start-up fuel<br />

composition, was approached [B1.4]. Preliminary results indicate that whatever the start-up (Pu,<br />

MA)O 2-x fuel composition, an equilibrium (Pu, MA)O 2-x fuel composition, with different Pu/MA ratio<br />

and Pu & MA vectors, is reached so that the equilibrium core can be (re)fuelled only by MAs. The<br />

"potential reactivity" (or k ∞ ) seems to be sufficient both for the core reactivity and for sustaining BU<br />

cycles.<br />

EFIT thermohydraulic and safety analyses. Parallel to the activity for the core design, a<br />

thermohydraulic numerical model of the EFIT reactor was developed with the system code RELAP5<br />

[B1.9]. Besides representing the first step in the dynamic simulation of the sub-critical reactor<br />

(coupled thermohydraulic and neutronic) for the safety analyses, the model allowed a preliminary<br />

investigation of safety issues in order to confirm the neutronic design. A preliminary layout of the<br />

primary system (fig. B1.9) that implemented all the basic design options for an industrial<br />

Absolute DH (W/kg)<br />

1000<br />

0<br />

1×10 -1 1×10 3 1×10 5 1×10 7 1×10 9<br />

Time (s)<br />

Fig. B1.8 – a) Coolant void effect; b) absolute decay heat (W/kg) vs time behaviour<br />

175 176 (177/8/9) 171<br />

TMDP JUN 5 1 (2/3/4)<br />

SGs<br />

Pumps<br />

Pth<br />

181 281 151<br />

112<br />

152<br />

170<br />

DHR<br />

153<br />

154<br />

182<br />

183<br />

184<br />

161<br />

160<br />

JUN 106<br />

JUN 105 JUN 103<br />

102<br />

82 62<br />

282<br />

283<br />

284<br />

100<br />

120<br />

210 211 110 111<br />

Outer Outer Inner Inner<br />

Average Hot Average Hot<br />

Core Core Core Core<br />

Fig. B1.9 – Schematic of EFIT primary system and RELAP5 nodalization<br />

Progress Report 2006<br />

94


Fig. B1.10 – Unprotected loss-of-flow transient –<br />

RELAP5 main parameters<br />

transmutator (the use of pure melted lead as coolant,<br />

elimination of intermediate loops, installation of heat<br />

exchangers and mechanical pumps inside the primary vessel,<br />

uranium-free fuel) was simulated starting from the neutronic<br />

results of the EFIT two-zone cylindrical model.<br />

The RELAP5 analyses were used to verify the capability of the<br />

thermohydraulic design to support high temperature and<br />

power density and to pass from MOX fuel to uranium-free<br />

fuel, both in operational and in accidental conditions. Both<br />

Design Basis and Design Extension Conditions (DBCs and<br />

DECs) were considered so as to have a first evaluation of the<br />

inherent safety behaviour of the plant. Figure B1.10 shows the<br />

main parameter trends for an unprotected loss-of-flow<br />

accident (100% power, natural circulation, full capability of<br />

steam generators, low capability of decay heat removal<br />

system, BOC conditions). The results show that a stable<br />

natural circulation capable of limiting cladding, fuel and<br />

coolant temperatures to acceptable values is quickly attained.<br />

M/M0, P/P0<br />

Temperature (°C)<br />

1×10 0<br />

6×10 -1<br />

Core power<br />

SG power<br />

Core flow<br />

2×10 -1 0<br />

400 600 800 1000<br />

1.4×10 3<br />

1×10 3<br />

8×10 2<br />

Core mass flow and power<br />

Inner core (hot) max temperature<br />

a)<br />

1429 1400<br />

728<br />

Tclad(hot)<br />

Tfuel(hot)<br />

684 Tlead(hot) 619<br />

4×10 2 Time (s)<br />

400 600 800 1000<br />

b)<br />

665<br />

A preliminary analysis with the SIMMER-III code of the steam generator tube rupture accident (single and<br />

multiple rupture) was performed for the preliminary design solution [B1.13]. A portion of the EFIT vessel<br />

around the steam generator was modelled, using a simplified cylindrical 2D geometry centred on the tube<br />

rupture location. The core structure was schematically represented in the model, and stagnant lead was<br />

considered inside the vessel. The results of these calculations show that neither steam explosion effects<br />

nor the risk of void formation inside the core are of concern in the SIMMER-III evaluation.<br />

Electron vs proton accelerator–driven subcritical system performance using TRIGA reactor at<br />

power. In the framework of the RACE project [B1.14] <strong>ENEA</strong> was concerned with studies on the energetic<br />

gain expected in the RACE core. It is assumed that the thermal power dissipated by the W-Cu or uranium<br />

RACE target during the high-power phase will be ~25 kW, which corresponds, according to preliminary<br />

MCNPX calculations on a depleted uranium multi-disk target undergoing a 1.0 mA - 25 MeV electron<br />

beam, to a source strength of ∼6×10 13 n/s.<br />

Different MCNPX [B1.15, B1.16] and TRIPOLI4 [B1.17] calculations were performed to analyse the<br />

coupling between a TRIGA (<strong>ENEA</strong> Casaccia) subcritical core and a photoneutron source and get a first<br />

assessment of the RACE target-core power coupling coefficients (energetic gain) and compare them with<br />

those obtained for the TRIGA Accelerator-Driven Experiment (TRADE) core configurations [B1.18]. Hence,<br />

for some calculations it was assumed that an electron beam impinges on a W-Cu target surrounded by<br />

[B1.10] NEA – OECD, Fuels and materials for transmutation. A status report. Nuclear Sci. ISBN 92-64-01066-1, NEA n. 5419, OECD (2005)<br />

[B1.11] IP EUROTRANS, Actions list: decay heat benchmark (2006)<br />

[B1.12] G. Glinatsis, Decay heat investigation on the U-free transmuter cores dedicated fuels, <strong>ENEA</strong> Internal Report in preparation<br />

[B1.13] H. Yamano et al., Simmer III: a computer program for LMFR core disruptive accident analysis - Version 3.A: Model summary and program<br />

description, O-arai Engeneering Center - Japan Nuclear Cycle Development Institute (2003)<br />

[B1.14] D. Beller, Overview of the AFCI reactor-accelerator coupling experiments (RACE) project, Presented at the 8 th Information Exchange<br />

Meeting on Actinide and Fission Product Partitioning and Transmutation (OECD/NEA) (Las Vegas 2004)<br />

[B1.15] MCNP4C A general Monte Carlo nparticle transport code, J.F. Briesmeister Ed., Los Alamos National Laboratory report, LA-13709- M<br />

(2000)<br />

[B1.16] J. S. Hendricks et al., MCNPX, VERSION 2.5.d, LA-UR-03-5916 (2003)<br />

[B1.17] J.P. Both et al., TRIPOLI4, a Monte-Carlo particles transport code. Main features and large scale application in reactor physics, Presented<br />

at the Inter. Conference on Supercomputing in Nuclear Application - SNA’2003 (Paris 2003)<br />

[B1.18] C. Rubbia et al., Nucl. Sci. Eng. 148, 103-123 (2004)<br />

References<br />

95<br />

Progress Report 2006


B1 R&D on Nuclear Fission<br />

B Fission Technology<br />

1mm<br />

Ø15<br />

Ø28.5<br />

17<br />

18<br />

19<br />

24<br />

6.5 cm<br />

Ø1.3<br />

60<br />

771<br />

504.7<br />

72.7 209.7<br />

105.3 83.5<br />

16.493<br />

4.311<br />

7.351<br />

7.351<br />

348 20 107<br />

Fig. B1.11 – TRADE-like conical shaped target. (dimensions in mm)<br />

1.7 mm<br />

12<br />

mm<br />

20 mm<br />

Fig. B1.12 – Multi-plate target<br />

Tantalum window<br />

(thickness=1 mm)<br />

Water<br />

(thickness=2 mm)<br />

Aluminium<br />

(thickness=1 mm)<br />

Depleted uranium<br />

Fig. B1.13 – UT-NETL core with central<br />

cylindrical uranium target<br />

the subcritical Rc-1 TRIGA core. These cases<br />

will be indicated in the following as TRADEelectrons<br />

(TRADE-e).<br />

Two core configurations, representative of the<br />

SC0 (-500 pcm) and SC2 (-3000 PCM) TRADE<br />

configurations, were coupled with three types of<br />

target. The simulations took into account<br />

electron, photon and neutron transport, using<br />

the MCNPX code. The material considered was<br />

a W-Cu alloy (75% wt and 25% wt respectively,<br />

bulk density 14.7 g/cm 3 ) in two geometrical<br />

shapes: raw cylindrical (h=8.89 cm, r=3.49 cm) and<br />

conical (aperture angle 16.5°, h=34.8 cm,<br />

r max =1.5 cm, radial thickness 0.19 cm), as shown in<br />

figure B1.11 [B1.19]. A third target type was<br />

represented by a set of coaxial disks of depleted<br />

uranium with aluminium cladding and water coolant<br />

(fig. B1.12). Uranium has the highest photoneutron<br />

production [B1.20].<br />

Given a fixed electron beam, the neutron source mainly<br />

depends on the target material, but the feasibility of the<br />

target configuration has to be considered. Some target<br />

concepts were analysed and the cooling capability of<br />

the system, choice of materials, thermomechanical<br />

behaviour and safety issues were discussed.<br />

Calculations by MCNPX were performed, mainly to<br />

estimate the different neutron sources (besides the<br />

power deposition distribution).<br />

The first target configuration considered was a bare uranium cylinder with r=3.25 cm and h=8 cm.<br />

This is not a feasible target solution as, for example, it does not allow proper cooling, but it is useful<br />

for estimating the maximum achievable neutron yield (some geometrical constraints have to be<br />

taken into account since the target is to be placed in the central channel of the core). The second<br />

and third target configurations were based on the conical geometry shown in figure B1.11. The<br />

materials considered were depleted uranium and tantalum, as for the TRADE target. The third<br />

configuration was a hollow uranium cylinder irradiated by the electron beam in its inner surface,<br />

where the power deposition was spread out to allow cooling. The photonuclear reaction data used<br />

for the MCNPX simulations were the LA150u and the BOFOD libraries, both collected and reported<br />

in the International Atomic Energy Agency (IAEA) photonuclear data library [B1.21].<br />

Ø63<br />

8.578<br />

Ø43<br />

Ø50.8<br />

Ø46<br />

Progress Report 2006<br />

96


Fig. B1.14 – Geometrical models<br />

Some analyses for the 1-MW TRIGA reactor were<br />

performed at the Nuclear Engineering Teaching Laboratory<br />

(NETL) of the University of Texas (UT). The UT-NETL core<br />

was explicitly modelled using MCNP-5 in a coupled<br />

electron/photon/neutron problem. Photonuclear data were<br />

taken from T-16 at the Los Alamos National Laboratory<br />

(LANL) and the electron source was a 25-MeV beam with a<br />

1-cm–diameter beam spot. A 25-kW beam power and a<br />

cylindrical uranium target in the central position were<br />

assumed (fig. B1.13).<br />

For the calculations performed by the TRIPOLI4 Monte<br />

Carlo code [B1.16], the geometry was a simplified “clean”<br />

Texas A&M University (TAMU) TRIGA core (fig. B1.14) having<br />

the same fuel composition as TRADE. Two core<br />

configurations, representative of SC2 (-3000 pcm) and SC3<br />

(–5000 pcm) TRADE configurations, were considered, with<br />

the external source located in central core position. The<br />

external neutron source was considered to have a spectrum<br />

similar to that of photoneutrons obtained through electron<br />

interaction with a Pb target of a 20-MeV linear accelerator<br />

(linac).<br />

Figures B1.15 and B1.16 show the core power vs the<br />

subcritical level for the different targets taken into account.<br />

The results are normalised at 25-kW beam power. The<br />

analysis shows the requirements for an electron-driven<br />

coupling experiment aimed at providing significant validation<br />

elements about the dynamic behaviour of an accelerator<br />

driven system (ADS), in terms both of target performance<br />

and of beam power characteristics. The results show that it<br />

is necessary to have a U target in the central position of the<br />

TRIGA reactor to obtain a core power greater than 50 kW<br />

for K eff >0.98. Such a minimum power is required to have<br />

SC2-K eff = 0.96816 SC3-K eff = 0.95037<br />

feedback effects in the system responses in the presence of source/reactivity transients, as indicated by<br />

preliminary analysis of the influence of thermal reactivity feedback in RACE.<br />

Some results for TAMU TRIGA configurations indicate tighter target/core coupling than in the Casaccia<br />

TRIGA RC-1 (TRADE-e), as can be seen by comparing the results in figure B1.16 relative to the same multiplate<br />

target in a central position in TAMU TRIGA and TRADE-e. Further investigations are needed. In any<br />

case, a final check should be performed for the actual core loading that could be envisaged for RACE-HP<br />

(high power).<br />

In-core test for the Piccolo-Micromegas neutron detector. One important step needed for approval<br />

of a demonstration device is experimental validation of simulations. Of particular interest is determination<br />

Core power (kW)<br />

100<br />

80<br />

60<br />

Ta conical in TRADE<br />

40<br />

W-Cu cylinder in TRADE<br />

20<br />

W-Cu conical in TRADE<br />

0<br />

0.95 0.97 0.99<br />

K eff<br />

Fig. B1.15 – Core power vs subcritical level for<br />

non–fissile targets (beam power 25 kW)<br />

Core power (kW)<br />

100<br />

80<br />

60<br />

40<br />

U hollow cylinder in TRADE<br />

U conical in TRADE<br />

20<br />

U multiplate in TRADE<br />

U multiplate in TAMU<br />

U in UT-NETL<br />

0<br />

0.95 0.97 0.99<br />

K eff<br />

Fig. B1.16 – Core power vs subcritical level for<br />

uranium targets (beam power 25 kW)<br />

[B1.19] P. Agostini et al., Neutronic and thermo-mechanic calculations for the design of the TRADE spallation target, Presented at the Inter.<br />

Conference on Accelerator Applications (Venice 2005)<br />

[B1.20] W.P. Swanson, Radiological safety aspects of the operation of electron linear accelerators, IAEA Technical Report, Series No.188,<br />

STI/DOC/010/188 (1979)<br />

[B1.21] Handbook on photonuclear data for applications: cross sections and spectra, IAEA-TECDOC-1178 (2000)<br />

References<br />

97<br />

Progress Report 2006


B1 R&D on Nuclear Fission<br />

B Fission Technology<br />

a)<br />

Detector<br />

35 mm<br />

Neutron/charged particle converter<br />

B-10<br />

Pads<br />

160μm 1mm20 mm<br />

Micromesh<br />

P3<br />

P4<br />

3 mm<br />

Th-232<br />

HV1<br />

U-235<br />

HV1<br />

HV2 P4<br />

HV2<br />

P1 P2 P1 P3<br />

P2<br />

Ceramic insulator<br />

Ar+ (2%) Iso-butane (1 bar)<br />

b)<br />

Fig. B1.17 – a) Piccolo-Micromegas assembly used in<br />

1–MW TRIGA Casaccia reactor test; b) schematic of the<br />

principle of Piccolo-Micromegas detector (in horizontal<br />

position) for neutron flux measurement<br />

of the neutron spectrum (i.e., neutron flux as a<br />

function of neutron energy) for different<br />

configurations of the subcritical device. As is<br />

well known, the neutron flux in an ADS consists<br />

of neutrons produced via spallation reactions in<br />

the target and fissions from the multiplying<br />

blanket. Unfortunately neutron spectra cannot<br />

be measured using only one type of detector. To<br />

cover the complete energy range of neutrons<br />

produced, a new neutron detector, named<br />

Piccolo-Micromegas, based on Micromegas<br />

technology has been developed in a<br />

cooperation with CEA/DAPNIA/SEDI (Saclay<br />

France) and CNRS/IN2P3 LPC (Caen France).<br />

The principle of Micromegas is based on<br />

detecting the electrons created by ionization of<br />

the filling gas by charged particles. Operation of<br />

Piccolo-Micromegas as a neutron detector<br />

requires an appropriate neutron/charged particle<br />

converter, which can be either the filling gas or<br />

the target, with a suitable deposit on the<br />

entrance window.<br />

Fissile elements such as 235 U, 232 Th are used<br />

simultaneously as neutron/charged particle<br />

converters in addition to 10 B and recoil ions of<br />

the gas (Ar + iC 4 H 10 quencher) filling the<br />

detector. Using four converters with a unique<br />

detector will permit practically on line extraction<br />

of a large range of the neutron flux spectrum in<br />

a specific position in the reactor. The large<br />

dynamic range of Piccolo-Micromegas will<br />

permit precise measurements and a detailed<br />

scanning of the flux into the whole reactor<br />

volume.<br />

At very high counting rate (>100 MHz)<br />

measurement will be performed on a current<br />

Fig. B1.18 – a) The six BNC cables; b) Piccolo- mode basis. At low counting rate, the fast<br />

Micromegas assembly inside the TRIGA reactor response of the detector will allow the incident<br />

particles to be counted one by one by means of<br />

a low-noise fast preamplifier. This will open up a<br />

way to measuring the neutron flux at the peripheral part of the reactor and, in some cases, also<br />

when full reactor power is not used.<br />

After a first test with the CELINA 14-MeV neutron source at Cadarache, a second test was<br />

performed with a sealed prototype placed inside the core of the TRIGA reactor at <strong>ENEA</strong> Casaccia<br />

in the configuration shown in figure B1.17. The detector was placed inside a long sealed stainless<br />

tube having the same dimensions as the empty reactor rod. The usual BNC (fig. B1.18a)) cables<br />

Progress Report 2006<br />

98


Configuration 250<br />

Fuel<br />

Graphite<br />

Piccolo Micromegas<br />

Source<br />

Regulating rods<br />

Shim 1 and 2 and<br />

safety rod<br />

Irradiation facility<br />

Rabbit<br />

Configuration 250<br />

Fuel<br />

Graphite<br />

Piccolo Micromegas<br />

Source<br />

Regulating rods<br />

Shim 1 and 2 and<br />

safety rod<br />

Irradiation facility<br />

Rabbit<br />

Fig. B1.19 – Position of Piccolo-Micromegas in the<br />

periphery of the TRIGA reactor core<br />

Fig. B1.20 – Position of Piccolo-Micromegas in the middle<br />

of the TRIGA reactor core<br />

were used and placed inside a<br />

10-m watertight stainless tube<br />

(fig. B1.18b)).<br />

Piccolo-Micromegas has 6000<br />

5×10 5<br />

worked at different reactor<br />

C4 (Th)<br />

powers from 10 W to 400 kW<br />

3×10 5<br />

at two different positions inside<br />

1×10 5<br />

the reactor: on the periphery<br />

0<br />

4000<br />

B-10<br />

0 100 200 300 400<br />

(fig. B1.19) and in the middle<br />

Reactor power (kW)<br />

(fig. B1.20). At low power,<br />

measurements were per -<br />

formed by simple counting on<br />

the pads; at higher power, only 2000<br />

the high-voltage current can<br />

H recoil<br />

be registered as the counting<br />

rate is too high. This<br />

experiment is aimed at<br />

studying the behaviour of the<br />

0<br />

0 100 200 300 400<br />

detector inside a nuclear<br />

Reactor power (kW)<br />

reactor. Several topics have<br />

been tackled, such as Fig. B1.21 – Currents vs reactor power and fission fragment counts from 232 Th vs<br />

response linearity vs the reactor power<br />

reactor power or ageing. The<br />

output energy spectra corresponding to the different converters have been also studied to get a thorough<br />

understanding of the detector response.<br />

Currents (nA)<br />

Counts/100 s<br />

1×10 6<br />

9×10 5 Th-FF counts per 100 s vs reactor power<br />

7×10 5<br />

An example of the results is shown in figure B1.21, which shows clearly that the new Piccolo-Micromegas<br />

can work in a nuclear reactor, which is a very aggressive experimental condition.<br />

Interaction of lead alloys with water. The aim of the experimental campaign is to assess the physical<br />

effects and possible consequences of interaction between LBE and the water from large leaks caused by<br />

a cooling-tube rupture inside the steam generator of a reactor such as XT-ADS or EFIT and to provide data<br />

for validation of the mathematical modelling.<br />

The relevant parameters for the tests were selected according to the XT-ADS reference design. The<br />

SIMMER code was adopted to simulate the experiments for the modelling activity. The ex LIFUS5 plant<br />

(fig. B1.22), designed and constructed to simulate this kind of interaction in a wide range of conditions<br />

(e.g., pressure up to 200 bar, temperature up to 500°C) was refurbished and re-arranged for the<br />

experiments.<br />

For Test n.1 (fig. B1.23), successfully carried out in March 2006, pressurized water was injected at 70 bar<br />

into the reaction vessel containing LBE at 350°C. The most important of the experimental results<br />

(fig. B1.23) in terms of pressure evolution in the reaction system is that a maximum value (78 bar) higher<br />

U-235<br />

99<br />

Progress Report 2006


B1 R&D on Nuclear Fission<br />

Fig. B1.22 – P&I of LIFUS5 plant<br />

B Fission Technology<br />

Pressure (bar)<br />

80<br />

60<br />

40<br />

20<br />

0<br />

0<br />

TC<br />

S4<br />

Pb-17Li<br />

S1<br />

V10<br />

1/2”<br />

V8<br />

V1 V2 LT2<br />

H 2 3”<br />

GS1<br />

D1 FA<br />

Al 1/2” PT1<br />

Al 1”<br />

V12 S5<br />

V6 V15<br />

Al 3”<br />

Al 10<br />

V13<br />

TC<br />

TC<br />

1-30<br />

PT11<br />

PT S2 TC<br />

PT7<br />

6-8<br />

H 2 O<br />

S1 PT9<br />

SP<br />

DPT<br />

TC3<br />

1<br />

PT5<br />

Pb-17Li TC2<br />

PT3<br />

TC<br />

PT<br />

2-4<br />

V11<br />

V3<br />

V5<br />

Wa 1/2”<br />

To vacuum<br />

pump<br />

V4<br />

GS2 V14<br />

Fig. B1.23 – Results of Test n.1<br />

S5<br />

1000 2000 3000<br />

Time (ms)<br />

than the water injection pressure (70 bar) was<br />

reached in the reaction-expansion vessel of LIFUS5<br />

during the test. This means that it is fundamental to<br />

adopt suitable and reliable countermeasures in order<br />

to avoid such pressure peaks in the reactor pool.<br />

Integral Circulation Experiment activities. In the<br />

framework of the Domain DEMETRA, <strong>ENEA</strong> is<br />

strongly involved in the “Large-Scale Integral Test”<br />

work package and is committed to performing an<br />

integral experiment with the aim of reproducing the<br />

primary flow path of the European Transmutation<br />

Demonstrator (ETD) pool nuclear reactor, cooled by<br />

LBE.<br />

Heat<br />

exchanger<br />

CIRCE vessel<br />

In 2006, <strong>ENEA</strong> worked on the design of a new test<br />

section (fig B1.24) to install in the CIRCE facility at<br />

<strong>ENEA</strong> Brasimone for the Integral Circulation<br />

Experiment (ICE). To achieve the goals of the integral<br />

test, a high thermal performance heat source (HS)<br />

Fig. B1.24 – ICE test section<br />

was required. The ICE heat source, consisting of a<br />

pin bundle made up of electrical heaters with a total thermal power of 800 kW, was designed to<br />

achieve a ΔT HS /L act value of 100°C/m, a pin power density of 500 W/cm 3 and an average liquid<br />

Riser<br />

Fitting<br />

volume<br />

TC<br />

PT10<br />

H 2 3”<br />

V7<br />

D2<br />

S3<br />

H 2<br />

Drainage<br />

1/2”<br />

V9<br />

V16<br />

Dead<br />

volume<br />

Fuel pin<br />

simulator<br />

Flow meter<br />

Progress Report 2006<br />

100


Table B1.I – Overview of the experimental parameters adopted for the ICE activity,<br />

compared with the ETD concepts foreseen<br />

XT-ADS EFIT ICE<br />

Coolant LBE Pure lead LBE<br />

Primary loop circulation Mechanical pump Mechanical pump Gas lift technique<br />

Fuel assembly lattice Hexagonal Hexagonal Hexagonal<br />

Fuel assembly type Wrapper Wrapper Wrapper<br />

Fuel assembly spacer Grid Grid Grid<br />

Fuel pin diameter (D) [mm] 6.55 8.72 8.2<br />

Pitch to diameter ratio (p/D) 1.41 1.56 1.8<br />

Fuel heat flux q’’ [W/cm 2 ] 85-115 100-140 100<br />

Fuel power density q’’’ [W/cm 3 ] 500-700 450-650 488<br />

Average velocity fuel pin region [m/s] 1 1 1<br />

Fuel pin active length [mm] 600 900 1000<br />

Tin/tout core [°C] 300/400 400/480 300/400<br />

ΔT HS /L act [°C/m] 167 88 100<br />

Fuel pin cladding material T91 T91 AISI 316L<br />

Secondary coolant Low pressure Water with Pressurized<br />

boiling water superheated water<br />

steam<br />

metal velocity of 1 m/s, in accordance with the<br />

reference value adopted for the ETD concepts (XT-<br />

ADS, EFIT). A pin bundle was chosen to simulate<br />

the HS in order to improve cooling of the heaters<br />

and avoid overheating of the cladding material. The<br />

HS was coupled to the test section by a suitable<br />

mechanical structure, designed by <strong>ENEA</strong>. The<br />

heaters and the mechanical structure which<br />

surrounds them make up the so-called fuel pin<br />

simulator (FPS). The main experimental para meters<br />

characterising the heat source (fig. B1.25) and ICE<br />

activity are reported in table B1.I.<br />

Fuel pins simulated by electrical heaters<br />

p<br />

h<br />

Assembly Hexagonal<br />

Diameter 8.2 mm<br />

Pitch/diam. 1.8<br />

Active length 1000 mm<br />

Active pins 31<br />

Total pins 37<br />

Fuel heat flux: 100 W/cm 2<br />

Thermal power pin: 26 kW<br />

A gas lift pumping system successfully tested and<br />

Fig. B1.25 – ICE heating section<br />

qualified during previous ex perimental campaigns<br />

in CIRCE is used to perform the ICE activity. A pressure head of 40 kPa is available to promote the LBE<br />

circulation along the flow path.<br />

The ICE test matrix has been defined, with the following tests foreseen:<br />

• Steady-state circulation: isothermal condition, LBE average temperature of 350°C, no power supply.<br />

The aim is to get fluid-dynamics characterisation of the test section.<br />

• Steady-state circulation: LBE average temperature of 350°C, full thermal power. The aim is to evaluate<br />

the coupling of the HS and heat exchanger (HX) and analyse the thermal hydraulic behaviour of a heavy<br />

liquid metal (HLM) pool system primary loop.<br />

• Transient condition: loss of cold sink, starting from the nominal condition. The aim is evaluate the trend<br />

of the average temperature through the HS and HX.<br />

• Transient condition: loss of pumping system, starting from the nominal condition. The aim is analyse the<br />

transition from forced to natural circulation and characterise the natural circulation flow regime in a HLM<br />

pool system.<br />

An appropriate cold sink was designed. Consisting of a prototypical LBE-pressurized water shell heat<br />

101<br />

Progress Report 2006


B1 R&D on Nuclear Fission<br />

B Fission Technology<br />

Tube side<br />

Assembly: Triangular<br />

Tubes: “U” - shape<br />

Num. tubes: 13(3/4”)<br />

Material: T91<br />

Pressure: 6 bar<br />

ΔT: 30°C<br />

Flow rate: 6.5 kg/s<br />

Velocity: 1.5 m/s<br />

Max ΔT wall: 285°C<br />

Fig. B1.26 – ICE heat exchanger<br />

VELLA - Virtual European Lead Laboratory<br />

exchanger made up of a seamless<br />

U–tube, it will be placed in the upper<br />

plenum of the main vessel (fig. B1.26).<br />

The possibility of installing and testing<br />

different prototypical HXs (i.e., helical<br />

tubes) is under evaluation. In any case<br />

the opportunity of adopting pressurized<br />

water as a secondary fluid has to be<br />

confirmed by the currently ongoing<br />

safety analysis.<br />

<strong>ENEA</strong> is responsible for coordinating the Virtual European Lead Laboratory (VELLA), which is an FP6<br />

integrated infrastructure initiative started in October 2006. The ambitious intent to homogenise<br />

European research in the field of lead technologies for nuclear applications thereby producing a<br />

common platform of work suggested dividing VELLA into Networking Activities (NAs), Transnational<br />

Access Activities (TAs) and Joint Research Activities (JRAs). The objectives of the NAs is to create<br />

a wide “virtual" community of researchers, define common standards and protocols for the use of<br />

the facilities and interact with other programmes and institutes operating in this field. The TA<br />

objectives are to promote access by researchers, universities and companies to current<br />

infrastructures and knowledge in order to increase the competitiveness of European industry. The<br />

TAs would also provide a framework for training young researchers to use the EU infrastructures<br />

during the three years of the project and for promoting mobility between the partners and the<br />

laboratories of the consortium. Finally, the JRA goals are to improve current knowledge on lead<br />

technologies, develop and operate heavy liquid metal (HLM) components and instrumentation,<br />

especially in a neutron irradiation environment and, finally, study HLM thermal hydraulics.<br />

<strong>ENEA</strong>, as coordinator, is involved in all the NAs, provides access to the infrastructures and<br />

participates in three of the four JRAs.<br />

In 2006 efforts were mainly devoted to management activities in order to rationally organise the work<br />

to be carried out. The management structure of VELLA was approved and the technical and<br />

scientific committees responsible for managing the JRAs and the access to infrastructures were set<br />

up. The activities to be performed in the framework of the JRAs were planned in detail and an<br />

appropriate quality control system established. <strong>ENEA</strong>’s activities also included financial<br />

management. A lot of work was also devoted to creating the “virtual” community, by constructing<br />

an official web-site [B1.22], intended to become a central point of information on HLM technologies.<br />

B1.2 Evolutionary and Innovative Reactors<br />

The main issue in this field in 2006 was the definition and launching of a three-year R&D national<br />

programme based on “strategic funding devoted to the National Electric System R&D” and<br />

focussed on participation in international initiatives such as the International Near-Term Deployment<br />

(INTD) and Generation-IV Nuclear Systems. The programme is being managed through a specific<br />

agreement between the Italian Ministry of Economic Development and <strong>ENEA</strong>, with the joint<br />

involvement of major national organisations still active in the nuclear sector, i.e., Ansaldo Nucleare,<br />

Ansaldo Camozzi, Del Fungo Giera Energia, Italian Universities Consortium for Research in Nuclear<br />

Technologies (CIRTEN) and SIET (an <strong>ENEA</strong> subsidiary SME). The total funds for the first year amount<br />

to 5.5 MEuro and comparable annual funds are expected for the rest of the programme. The main<br />

goals of the programme are to<br />

Progress Report 2006<br />

102


• keep open the future nuclear energy option in the country;<br />

• contribute to the development of innovative nuclear systems which promise to be “sustainable”,<br />

acceptable by the public and economically interesting;<br />

• sustain the growth of the necessary competences through participation in promising projects with solid<br />

foundations;<br />

• support the effort required by national industry to keep up with the pace at world and domestic level.<br />

In particular, the national R&D programme supports experimental and analytical activities for the further<br />

development of the GENIII+ International Reactor Innovative and Secure (IRIS) and GENIV Lead-Cooled<br />

Fast Reactor (LFR) as well as some technological activities as support to the GENIV Very High Temperature<br />

Reactor (VHTR) and to the GENIII AP1000 reactor.<br />

This national programme is also intended to be synergic and coherent with the Generation-IV initiative as<br />

well as with a number of the Sixth European Framework Programme (FP6) projects: the European Lead-<br />

Cooled System (ELSY), coordinated by Ansaldo Nucleare; the Reactor for Process Heat, Hydrogen and<br />

Electricity Generation (RAPHAEL); Roadmap for a European Innovative Sodium Cooled Fast Reactor<br />

(EISOFAR); Assessment of Liquid Salts for Innovative Applications (ALISIA).<br />

<strong>ENEA</strong> also participates in the “Coordination Action” Sustainable Nuclear Fission Technology Platform (CA<br />

SNF-TP), which is in charge of developing a coherent European strategy on<br />

nuclear fission and consolidating the European and Euratom position<br />

within the GIF initiative and in the linked Coordination Action<br />

Partitioning and Transmutation European Roadmap for<br />

Sustainable Nuclear Energy (PATEROS), aimed at “delivering<br />

a European vision for the deployment of the partitioning and<br />

transmutation technology up to the scale level of pilot<br />

plants for all its components”.<br />

The following is a short summary of the main results<br />

achieved over 2006 with reference to the innovative<br />

nuclear systems developed within the abovementioned<br />

programmes and projects.<br />

Suppression<br />

pools<br />

Dry well<br />

containment<br />

International Reactor Innovative and Secure<br />

IRIS (fig. B1.27) is designed as an advanced, modular<br />

small-medium reactor. It is an integral-type pressurizedwater<br />

reactor with a power level of 335 MWe, featuring an<br />

integral primary system configuration with all the main<br />

components (reactor coolant pumps, steam generators, pressurizer,<br />

control rod drive mechanisms) located within the reactor vessel. This<br />

configuration enables a simplified design with enhanced reliability and economics and supports its safetyby-design<br />

approach, which results in exceptional safety characteristics. In addition to electricity-only<br />

production, IRIS is also well suited for cogeneration, including water desalination, district heating, and<br />

process steam generation.<br />

Fig. B1.27<br />

–<br />

The<br />

IRIS reactor<br />

Furthermore, IRIS well fits the recently announced US Department of Energy initiative - Global Nuclear<br />

Energy Partnership (GNEP) - aimed at supporting worldwide expansion of the use of nuclear energy in a<br />

responsible and proliferation-resistant way. Within the GNEP framework, IRIS can - in the near term - offer<br />

an advanced reactor design to satisfy the need for smaller, grid-appropriate reactors.<br />

[B1.22] www.3i-vella.eu.<br />

References<br />

103<br />

Progress Report 2006


B1 R&D on Nuclear Fission<br />

Fig. B1.28 – Sketch of the SPES-3 integral testing facility<br />

Containment<br />

Primary pump<br />

B Fission Technology<br />

Long term<br />

gravity makeup<br />

system<br />

Pressure<br />

suppression<br />

pools<br />

Reactor cavity<br />

Emergency<br />

boration<br />

tanks<br />

Integral reactor<br />

pressure vessel<br />

Fig. B1.29 – Sketch of ELSY reactor block<br />

Pb<br />

IRIS is being developed by an international team, led<br />

by Westinghouse, incorporating organisations from<br />

ten countries, including Italy (<strong>ENEA</strong>, CIRTEN,<br />

Ansaldo Nucleare, Ansaldo Camozzi and SIET). The<br />

preliminary design has been completed and the<br />

testing needed for design certification just started in<br />

2006. The centrepiece of the testing programme is<br />

the integral system testing to be performed at the<br />

SIET facility in Italy. Since mid-2006, a multinational<br />

group of experts coordinated by Westinghouse and<br />

<strong>ENEA</strong> has been designing the SPES-3 experimental<br />

facility, devoted to an integral testing campaign for<br />

the IRIS reactor licensing process. The advanced<br />

safety features of the IRIS reactor require a unique<br />

test facility, where both the containment system and<br />

the primary system are simulated (fig. B1.28).<br />

Moreover, the scaling approach suggested the<br />

adoption of an integral layout for the facility as well.<br />

The SPES-3 integral test facility to be built at the<br />

SIET labs is a full height, full pressure and<br />

temperature, scaled volume facility (1:100 power<br />

and volume ratio). The main components, i.e., the<br />

helical coil steam generators, the core bundle<br />

simulator, the pressurizer, are integrated in the tall<br />

reactor pressure vessel as in the IRIS design. The<br />

facility is designed both for integral testing and for<br />

separate effect tests. A “simulation group” has been<br />

set up to support both the design of the facility and<br />

the pre-test and post-test analyses. Both bestestimate<br />

system codes (RELAP, GOTHIC) and CFD<br />

codes (Fluent) are adopted.<br />

B4C rods<br />

(36 As)<br />

Fuel outer<br />

(54 FAs;E pu =23.8%)<br />

Fuel intermediate<br />

(90 FAs;E pu =18.9%)<br />

Fuel inner<br />

(109 FAs;E pu =15.6%)<br />

Fig. B1.30 – The open square<br />

lattice ELSY core<br />

European Lead-Cooled<br />

Fast System<br />

The ELSY reference design<br />

(fig. B1.29) is a 600–MWe<br />

pool-type fast reactor cooled<br />

by pure lead. This concept has<br />

been under development since<br />

September 2006 and is<br />

sponsored by the Euratom<br />

FP6. The ELSY project,<br />

coordinated by Ansaldo<br />

Nucleare, is being performed<br />

by a consortium consisting of<br />

twenty organisations including<br />

<strong>ENEA</strong>, CIRTEN and CESI<br />

Ricerca from Italy. ELSY aims<br />

to demonstrate the possibility<br />

Progress Report 2006<br />

104


of designing a competitive<br />

and safe fast critical reactor<br />

using simple engineered<br />

technical features, whilst<br />

fully comply ing with the<br />

Generation-IV goal of MA<br />

burning capability.<br />

The activities carried out in H active fuel 1100 mm<br />

2006 were mainly devoted<br />

to defining requirements,<br />

selecting options and verifying critical issues. The requirements reflect the GEN IV goals of sustain ability,<br />

economics, safety, proliferation-resistant and physical protection. Sustainability is the leading criterion for<br />

core design, which focusses on demonstrating the potential of the reactor to be self-sustaining in<br />

plutonium and to burn its own generated MAs. Two different core configurations are being studied:<br />

wrapperless assemblies in a square lattice where pins are arranged in square bundles as well (fig. B1.30),<br />

or more conventional wrapped assemblies in a hexagonal lattice. Both the concepts assume the same<br />

thermal power (1500 MWth), fuel (MOX), fuel residence time (5 years), BU (100 MWd/kgHM for the hottest<br />

assembly), cladding (T 91 with a maximum allowable temperature of 550°C), cladding radiation damage<br />

(100 DpA), inlet (400°C) and outlet (480°C) core temperature. The comparison focusses on conversion<br />

factor and MA burning capability (sustainability); core dimensions, loading factor, fuel inventory, peak and<br />

average power density (economics); coolant velocity (on which corrosion and natural circulation depend),<br />

control-rod system, coolant void/density effect and reactivity coefficients (safety); use or not of axial<br />

blankets (proliferation).<br />

In order to provide the core design with some boundary conditions, a preliminary T/H analysis of the fuel<br />

rod was also performed with the RELAP5 code. The parameter-set for open square SA in table B1.II was<br />

fixed on the basis of engineering considerations, previous LFR designs and current knowledge on lead<br />

technology. As the cladding temperature is considered<br />

the most critical parameter to meet safety requirements<br />

in heavy liquid metal (HLM) reactors, aluminized T91<br />

steel was selected as cladding material to increase the<br />

safety limit in operating conditions (T clad < 550 °C).<br />

Preliminary parametric calculations allowed<br />

determination of the maximum admissible linear power<br />

to meet such a limit; the result was a maximum form<br />

factor of the radial power distribution of 1.2 (fig. B1.31).<br />

However, this preliminary evaluation could be too<br />

conservative. Indeed, applying different empirical<br />

correlations from the literature for single-phase heat<br />

transfer in lead and LBE, the corresponding cladding<br />

temperature distributions are pretty different<br />

(fig. B1.32). In short, the correlations recently derived<br />

for rod bundle geometry abate the heat transfer<br />

resistance and may be beneficial for the design of an<br />

LFR. For instance, using the Zhukov’ correlation<br />

(developed in the framework of the BREST reactor), the<br />

cladding peak temperature (red or brown line) is about<br />

40°C lower than the value calculated with the<br />

correlation implemented in the RELAP code<br />

(yellow line).<br />

Concerning lead technology, <strong>ENEA</strong> coordinates all the<br />

activities to be performed in the work package and<br />

dedicates a strong effort to investigating the physical<br />

Table B1.II – Design parameters for LFR square open SA<br />

Thermal power 1500 MW # FA 240<br />

Av. linear power 200 W/cm FA Square 17x17<br />

Inlet temperature 400 °C Power/FA 6.25 MW<br />

Outlet temperature 480 °C Axial shape factor 1.16<br />

Total mass flow 126157 kg/s D fuel pellet 7.14 mm<br />

D pin 8.5 mm Gap thickness 0.115 mm<br />

Pitch 13.6 mm Clad thickness 0.565 mm<br />

Temperature (°C)<br />

Elevation (m)<br />

580<br />

560<br />

540<br />

Acceptable clad max temp=550°C<br />

520<br />

0.9 1.1 1.3 1.5<br />

Radial shape factor<br />

Fig. B1.31 – Peak cladding temperature at different<br />

radial shape factors<br />

1.0<br />

0.8<br />

0.6<br />

0.4<br />

0.2<br />

Lead temperature<br />

Borishanski<br />

Graber<br />

Calamai<br />

Zhukov (no spacers)<br />

Zhukov (spacers)<br />

Subbotin<br />

Kirillov-Stromquist<br />

Lubarsky<br />

“clean”<br />

“dirty”<br />

0<br />

380 420 460 500 540 580<br />

Temperature (°C)<br />

Fig. B1.32 – Effect of the different correlations on the<br />

peak cladding temperature<br />

105<br />

Progress Report 2006


B1 R&D on Nuclear Fission<br />

and chemical properties of lead and its interaction with the structural materials and the secondary<br />

coolant, as well as evaluating corrosion protection-coatings and corrosion-resistant steels for<br />

cladding, pump impellers, etc.<br />

B Fission Technology<br />

Following a critical review of the collection of existing data on lead thermophysical properties carried<br />

out by <strong>ENEA</strong>, Bologna University and the Belgian Nuclear Research Centre (SCK-CEN), a consistent<br />

database on the design-relevant properties is being compiled.<br />

<strong>ENEA</strong>’s experience in LBE technology has been invaluable in extrapolating the technological<br />

solutions (technologies, components, instrumentation) developed for lead bismuth to pure lead. In<br />

addition, <strong>ENEA</strong> has contribut ed, with its knowledge on purification, to a critical review of LBE<br />

properties and has participated in the collection of information on the oxygen control system (OCS),<br />

instrumenta tion and procedures (filling, draining, component removal).<br />

Very high temperature reactor<br />

In consideration of the helium loop (HE-FUS3) available at <strong>ENEA</strong> Brasimone plus past experience in<br />

the relative modelling, <strong>ENEA</strong> became a partner in the Reactor for Process Heat, Hydrogen and<br />

Electricity Generation (RAPHAEL) Consortium in May 2006. RAPHAEL, coordinated by AREVA NP<br />

SAS France, is an FP6 Integrated Project aimed at developing technologies for gas systems with<br />

temperatures ranging between 850 and 1000°C.<br />

<strong>ENEA</strong>’s contribution concerns three sub-projects: coupled reactor physics and core thermo-fluid<br />

dynamics, component development and safety. In particular, <strong>ENEA</strong> will test a prototypical heat<br />

exchanger (HEATRIC mockup) with helium at the primary and secondary sides in the HE-FUS3<br />

facility (fig. B1.33). The main experimental conditions will reproduce the operating conditions<br />

expected for the component: pressure 2.4 MPa and He flow rate 0.0475 kg/s in both sides, I/O<br />

temperatures 508-127°C in the primary side and 108-488°C in the secondary side. The<br />

experimental data from the tests at HE-FUS3 (several steady states and two loss of flow [LOFA]<br />

transients (fig. B1.34) in a wide range of working conditions) will be used in a benchmark exercise<br />

for validation of the thermal-hydraulics system transient codes.<br />

GAS<br />

ANALYSIS<br />

HEATRIC<br />

FV262<br />

OUT IN<br />

FV23ø<br />

L263<br />

MIXER<br />

FV234<br />

FV1<br />

FV7<br />

PSE265<br />

VACUUM<br />

FV261<br />

FV231<br />

PSE257 HV251<br />

HV252<br />

HV25ø<br />

E219/1 E219/2 E219/3<br />

HEATER HEATER HEATER<br />

BY-PASS<br />

E214<br />

ECONOMIZER<br />

PSV<br />

269<br />

FT<br />

228<br />

FV213<br />

FV4<br />

PSV268<br />

FV235<br />

FV5<br />

L264<br />

MIXER<br />

FT212<br />

COLD<br />

TEST SECTION<br />

E24ø<br />

COOLER<br />

PCV246<br />

PCV248<br />

FV249<br />

PSE2ø9<br />

FV6<br />

HELIUM<br />

DISCHARGE<br />

SYS<br />

V2ø5<br />

TANK<br />

HV289<br />

S26ø<br />

FILTER<br />

PSV2ø8<br />

VACUUM<br />

FV9<br />

FV8<br />

PURIFICATION OUT<br />

PURIFICATION<br />

IN<br />

FV1ø<br />

K2øK2ø<br />

COMPRESSOR<br />

HV2<br />

Fig. B1.33 – HE-FUS3 facility with HEATRIC<br />

mockup<br />

HE BOTTLES<br />

PRV244 PCV246 FV247<br />

HV243<br />

HELIUM<br />

FILLING<br />

HV3øHV3ø SYS<br />

Progress Report 2006<br />

106


Fig. B1.34 – LOFA transient – test section temperature<br />

at different positions and mass flow rate<br />

Finally, in order to provide experimental data<br />

for the validation of neutronics deterministic<br />

codes, <strong>ENEA</strong> will perform benchmark<br />

experiments in the fast source reactor<br />

TAPIRO of <strong>ENEA</strong> Casaccia. These<br />

experiments will make it possible to<br />

Temperature (°C)<br />

reproduce the strong changes in the neutron spectrum at the interface core/reflector, peculiar to hightemperature<br />

gas reactor (HTGR) systems.<br />

600<br />

500<br />

400<br />

800<br />

600<br />

400<br />

300<br />

200<br />

0 40 80 120 160 200<br />

Time (s)<br />

Mass flow rate (kg/h)<br />

B1.3 Nuclear Safety<br />

Nuclear safety studies are performed in the framework of international programmes. During 2006 the<br />

activities addressed code validation and accident analysis, severe accidents, and reliability and risk<br />

analysis.<br />

Code validation and accident analysis<br />

Mainly performed within a bilateral agreement funded by<br />

the French Institute for Radioprotection and Nuclear Safety<br />

(IRSN), the activities are summarised in the following.<br />

Analysis of the BETHSY experiment 4.3b. The CESAR<br />

thermal-hydraulic module of the Accident Source Term<br />

Evaluation Code (ASTEC) V1 was validated against<br />

experiment 4.3b at the CEA Grenoble BETHSY facility,<br />

which simulates a multiple steam generator tube rupture in<br />

a French PWR-900 reactor.<br />

Comparison of the CESAR results with experimental data<br />

confirms the capability of the code to well simulate<br />

accident situations in such reactors and, in general, the<br />

test parameters and phenomena are well reproduced. In<br />

particular, a) the depressurization rate of the primary and<br />

secondary sides is well calculated by the code<br />

(fig. B1.35); b) in both test and calculation the restart of<br />

the primary pump is effective in recovering the circulation<br />

in the secondary side, leading to a rapid depressurization<br />

towards stable and safe conditions; and c) the appearance<br />

and disappearance of stratification phenomena in the<br />

secondary side of the broken steam generator are well<br />

reproduced by the code (fig. B1.36).<br />

PWR-1300 H3 sequence analysis. A severe accident<br />

sequence resulting from a station blackout with total<br />

unavailability of auxiliary and safety systems after reactor<br />

scram in a French PWR-1300 plant was calculated with<br />

the integral ASTEC V1.2 up to core relocation and vessel<br />

rupture. The ASTEC results before core degradation takes<br />

place were compared with the results of the same<br />

sequence calculated with CATHARE2 V2.5 code in order<br />

Pressure (Pa)<br />

Temperature (K)<br />

1.6×10 7<br />

1.2×10 7<br />

8.0×10 6<br />

4.0×10 6<br />

560<br />

540<br />

520<br />

0<br />

Rapid<br />

cooldown<br />

Break opening<br />

Spray on<br />

Slow cooldown<br />

Pump 2<br />

restart<br />

0 8000 16000<br />

Time (s)<br />

Fig. B1.35 – Primary and secondary pressure (solid lines)<br />

compared with experimental data (dots)<br />

Break flow reverses<br />

500<br />

0 4000 8000 12000 16000<br />

Time (s)<br />

Fig. B1.36 – Steam generator riser wall temperature (solid<br />

line) at different heights compared with experimental data<br />

(dots)<br />

107<br />

Progress Report 2006


B1 R&D on Nuclear Fission<br />

120<br />

Qliq CATHARE<br />

Qliq ASTEC<br />

Fig. B1.37 – Pressurizer safety valve mass flow rate<br />

(ASTEC – CATHARE result comparison)<br />

B Fission Technology<br />

Flow rate (kg/s)<br />

H(m)<br />

80<br />

40<br />

Qvap ASTEC<br />

Qvap CATHARE<br />

0<br />

6000 10000 14000<br />

Time (s)<br />

4.74<br />

2.94<br />

1.14<br />

-0.657<br />

-2.45<br />

-3.6 -1.8 0 1.8 3.6<br />

R(m)<br />

3000<br />

2500<br />

2000<br />

1500<br />

1000<br />

600<br />

T(K)<br />

Fig. B1.38 – Core melt relocation at transient end<br />

(ASTEC code result)<br />

to highlight the differences between the two<br />

codes.<br />

In spite of some discrepancies in the initial<br />

phase, the time evolution of the main thermalhydraulic<br />

parameters of the primary and<br />

secondary systems calculated by ASTEC is, in<br />

general, similar to that calculated by<br />

CATHARE2. The largest discrepancy was found<br />

in the pressurizer safety valve operation<br />

modelling (fig. B1.37), which is much more<br />

simplified in ASTEC than in CATHARE2.<br />

In-vessel core melt progression and hydrogen<br />

generation were evaluated with the DIVA<br />

degradation module of ASTEC until corium<br />

relocation in the lower plenum and lower head<br />

vessel failure (fig. B1.38). A sensitivity study on<br />

more uncertain core degradation parameters<br />

highlighted their importance for in-vessel core<br />

melt progression and hydrogen release. In<br />

particular, in the fuel rod candling process,<br />

relocation parameters, such as velocity and<br />

minimal liquid fraction for the beginning of flow<br />

down, may notably affect the timing and<br />

amount of corium relocated in the lower head<br />

and the in-vessel hydrogen mass produced.<br />

QUENCH-11 post-test analysis. The boil-off QUENCH-11 experiment conducted at<br />

Forschungszentrum Karlsruhe (FZK) was analysed with the ICARE/CATHARE code. At first, the<br />

calculation was performed with the ICARE2 code in stand-alone mode for the participation in the<br />

semi-blind QUENCH-11 benchmark promoted by the European Commission within the Severe<br />

Accident Research Network (SARNET) project. Afterwards, the post-test analysis was carried out<br />

using the more recent coupled version V2 of ICARE/CATHARE.<br />

Temperature (K)<br />

2000<br />

1400<br />

800<br />

TFS 2/11<br />

TFS 5/11<br />

Tc3_75cm (icare2)<br />

Tc3_75cm (IC_v2)<br />

Reflood<br />

Flow rate (kg/s)<br />

0.0015<br />

0.0009<br />

0.0003<br />

Boil-off phase<br />

200<br />

0 2000 4000 6000<br />

Time (s)<br />

Fig. B1.39 – Clad temperature at 0.75 m elevation<br />

0<br />

5400 5600 5800 6000<br />

Time (s)<br />

Fig. B1.40 – Hydrogen generation during reflood<br />

ICARE 2 (green line), IC V2 (blue line), est. (red line)<br />

Progress Report 2006<br />

108


The ICARE2 and ICARE/CATHARE V2 codes were successfully applied in the post-test analysis of<br />

QUENCH-11. Code-to-code result differences, depending on the thermal-hydraulic model used, were<br />

pointed out and explained against experimental data. In spite of some deviations in the prediction of the<br />

initial boiling rate and collapsed water level, in general, both codes simulate quite well the boil-off phase<br />

(fig. B1.39). Both codes are also able to predict the large amount of hydrogen measured during reflood<br />

(fig. B1.40): ICARE2 well predicts the total mass of hydrogen produced, but the timing of hydrogen<br />

generation is notably delayed; whereas ICARE/CATHARE V2 predicts the timing of hydrogen release better<br />

than ICARE2, but it underestimates the total hydrogen production. Finally, the sensitivity analysis with<br />

ICARE/CATHARE V2 on some significant and uncertain code model parameters has highlighted the<br />

importance of some code model parameters relative to hydrogen generation during reflood.<br />

Spent fuel pool uncovery accident analysis. The consequences of an uncovery accident in an<br />

irradiated fuel assembly during unload operations in the pool of the spent fuel building was simulated with<br />

the ICARE/CATHARE code considering progressive pool draining, which is a more realistic scenario than<br />

the instantaneous draining studied in 2005.<br />

Two models were developed to simulate a water level decrease equal to 12.5 cm/min. One ("true draining")<br />

considers that the system is initially filled with water and the progressive level decrease is obtained by<br />

imposing as boundary condition a decrease in the pressure difference between the top and bottom of the<br />

fuel assembly. The other ("water level simulated") takes into account the effects of the level decrease on<br />

the fuel assembly and imposes a boundary condition on the surface of the fuel rods, which reproduces the<br />

thermal transfer between the fuel rods and the water of the system (axial profile of the exchange coefficient<br />

as a function of time).<br />

The two models give very similar results. Figure B1.41 shows the axial temperature profiles in the fuel<br />

assembly calculated with the two models during pool draining, 1000 s after the beginning of the accident.<br />

The water level (true or simulated) is indicated by the arrow. The fuel assembly is completely uncovered<br />

after 1850 s and the first temperature<br />

escalation, driven by Zircaloy oxidation<br />

under air atmosphere, occurs in the lower<br />

part of the fuel assembly at around 1 m of<br />

level, after about 4000 s of transient.<br />

It is worth noting that minor code<br />

“adjustments” to the calculations were<br />

necessary with the true draining model in<br />

order to obtain physical results during the<br />

water level decrease. In particular, the lack<br />

of a stratification model led to an erroneous<br />

calculation of the heat transfer between the<br />

structures and the fluid and, within the fluid,<br />

between the liquid and the gas phase.<br />

Modification of the dry-out criterion was<br />

necessary to avoid non-physical behaviour.<br />

Temperature (°C)<br />

400<br />

300<br />

200<br />

100<br />

0<br />

Row 1 (true draining)<br />

Row 1 (water level simulated)<br />

Row 2 (true draining)<br />

Row 2 (water level simulated)<br />

Row 3 (true draining)<br />

Row 3 (water level simulated)<br />

Row 4 (true draining)<br />

Row 4 (water level simulated)<br />

Row 5 (true draining)<br />

Row 5 (water level simulated)<br />

0 1 2 3 4<br />

Elevation (m)<br />

Fig. B1.41 – Temperature axial profiles 1000 s after the accident<br />

beginning<br />

Severe accident analysis<br />

The severe-accident studies in progress within the SARNET project dealt with the following topics during<br />

2006:<br />

LOFT LP-FP-2 experiment analysis. The LP-FP-2 test, performed in the Loss-of Fluid Test (LOFT)<br />

facility at the Idaho National Engineering Laboratory (INEL) USA to provide information on fuel rod<br />

behaviour, hydrogen generation, and fission-product release during a loss-of-coolant accident scenario in<br />

a pressurized water reactor (PWR) up to core reflood, was analysed with ASTEC V1 to assess the ability<br />

of the code to simulate thermal-hydraulic conditions and core degradation phenomena. The ASTEC results<br />

were then compared with the results of the ICARE/CATHARE code.<br />

109<br />

Progress Report 2006


B1 R&D on Nuclear Fission<br />

B Fission Technology<br />

ASTEC simulates reasonably well the transient phase of the experiment before the reflood phase,<br />

that is, reactor system thermal-hydraulics, core uncovery and heatup, hydrogen generation and<br />

fission-product release. The total hydrogen release is in good agreement with test measurements.<br />

Instead the code needs some improvement in order to investigate the reflood phase because<br />

temperature excursions and consequent heavy degradation of the fuel rods, hydrogen release and<br />

primary pressure increase are not reproduced by ASTEC because of the inadequate modelling.<br />

In general, the ICARE/CATHARE results confirm the validity of the ASTEC results.<br />

MOZART experiment analysis. A preliminary comparison between the air oxidation model<br />

actually implemented in the ICARE2 code that simulates the reaction kinetics between zircaloy and<br />

oxygen with a parabolic law and the first isothermal experiments carried out in the MOZART facility<br />

by IRSN and related to zircaloy-4 non-oxidized samples in the temperature range 800 to 1000°C<br />

was performed for Work-Package WP9-3 (zircaloy oxidation by air and steam-air mixture).<br />

Figure B1.42 shows calculated and measured (thermo-balance) mass gain vs time, at four different<br />

temperatures (800, 900, 950 and 1000°C). The experimental data exhibit parabolic behaviour for a<br />

very short time (roughly 30 min at 800°C). During this period, the calculated mass gain is<br />

overestimated, except at<br />

10000<br />

1000°C. At this<br />

temperature, the<br />

experimental protocol<br />

(iso thermal con ditions)<br />

1000<br />

cannot be completely<br />

met because the<br />

Mass gain/S (mg/dm 2 )<br />

100<br />

MOZART test 29 (1000°C)<br />

MOZART test 30 (1000°C)<br />

MOZART test 31 (1000°C)<br />

ICA/CATH (1000°C)<br />

MOZART test 33 (950°C)<br />

MOZART test 34 (950°C)<br />

ICA/CATH (950°C)<br />

MOZART test 39 (900°C)<br />

MOZART test 40 (900°C)<br />

ICA/CATH (900°C)<br />

MOZART test 44 (800°C)<br />

MOZART test 45 (800°C)<br />

ICA/CATH (800°C)<br />

10<br />

1 10 100 1000<br />

Time (min)<br />

Fig. B1.42 – Measured and calculated O 2 mass gain<br />

totally inadequate to predict the mass gain (underestimation of the reaction kinetics).<br />

oxidation power<br />

produces a not negligible<br />

temperature peak at the<br />

beginning of the test.<br />

After the loss of parabolic<br />

behaviour (post breakaway<br />

period), experi -<br />

mental data indicate a<br />

continuous increase in<br />

the oxidation kinetics and<br />

the code model becomes<br />

The model limitations in the simulation of post break-away oxidation may be more or less important,<br />

depending on the expected temperature evolution during accidental transients. However an<br />

improvement in the code model to take into account the post break-away behaviour is necessary<br />

to simulate uncovery accidents in the spent fuel pool, as the temperature increases gradually and<br />

most oxidation occurs in the post break-away kinetics regime.<br />

ASTEC reactor application and benchmarking. The work carried out in 2006 concerned a)<br />

benchmarking of ASTEC V1.2 R1 and MELCOR 1.8.6. based on the accident reactor sequence H2<br />

and b) identification of the most critical parameters and variables influencing the code response,<br />

mainly for in-vessel processes. This activity was shared with AREVA-NP SAS and IRSN. AREVA<br />

used the MAAP code for benchmark and successive comparisons.<br />

Details explaining the differences that emerged during model comparison are briefly reported. The<br />

main difference was found in some corium processes, mainly in candling. The candling model in the<br />

MELCOR “COR” package is semi-mechanistic and refers to the downward flow of molten core<br />

materials and subsequent refreezing of these materials as they transfer latent heat to cooler<br />

structures below. ASTEC uses a different model and so some differences are now clearly<br />

understood.<br />

Progress Report 2006<br />

110


Concerning hydrogen production, at the moment there are still some unexplained questions. There are not<br />

negligible gaps between the results provided by the codes involved in the benchmark. Very recently <strong>ENEA</strong><br />

made a simple comparison referring to the table with the timing of the main events of accident sequence<br />

H2 and found very strong differences between new and old MAAP calculations, between <strong>ENEA</strong>-ASTEC<br />

and AREVA-ASTEC calculations and between the latest MELCOR and MAAP calculations. Probably MAAP<br />

and MELCOR users followed completely different approaches in modelling the main processes occurring<br />

during corium production and mass relocation; perhaps they used different values in the most<br />

representative coefficients governing some relevant equations.<br />

Concerning the water inventory strong differences were found for water in the primary and secondary<br />

circuits given by ASTEC and MELCOR calculations, due to a totally different approach of calculation inside<br />

the codes. So far, code benchmarks have been performed without well-defined boundary and initial<br />

conditions, as generally made (imposed) during the OECD ISPs. For this reason a new benchmark clearly<br />

defining a list of still open issues has been recommended, with also a uniform protocol for calculations.<br />

Reactor safety source-term activities. An assessment of UO 2 vapourisation in different atmospheres<br />

was performed against some experiments conducted at Berkeley University [B1.23] with the aim of testing<br />

the fuel oxidation/vapourisation model implemented in ELSA [B1.24], which is the fission product release<br />

module of the European reactor ASTEC [B1.25].<br />

The experiments were modelled as a simple bare UO 2 fuel mass inside a gas flow channel. As the model<br />

departs from a fixed value of the equilibrium stoichiometrical deviation, the initial phase of experiments<br />

leading to fuel oxidation was neglected and only the volatilisation phase due to steam ingress was<br />

reproduced. Two steam-flow values of of 200 and 50 ccm were considered. The results show negligible<br />

differences in vapourisation rates. This is in good<br />

agreement with the fact that the ELSA vapourisation<br />

model slightly depends on the inlet gas rate and on<br />

the composition of the career gas. The calculated<br />

percentage of volatilised mass notably increases with<br />

temperature, which is further confirmation of the<br />

code capability to correctly calculate vapourisation<br />

rates.<br />

Comparison of code results with the experimental<br />

data normalised to mass fraction release, as given by<br />

the code, shows reasonably good agreement<br />

between calculation and data (fig. B1.43), thus<br />

providing further confidence in the adequacy of the<br />

fuel volatilisation modelling in ASTEC.<br />

Volatilisation rate<br />

1×10 -7<br />

1×10 -8<br />

Volatilisation rate of uranium in pure steam<br />

at flow rate 200 ccm<br />

Exp. (normalised to<br />

fractional volat. rate)<br />

1×10 -11<br />

1×10 -9<br />

Exp.<br />

(mol/s/cm 2 )<br />

1×10 -10<br />

ASTEC-DIVA<br />

(fractional volat. rate)<br />

5 5.5 6 6.5 7<br />

10 4 / T (1/K)<br />

Fig. B1.43 – DIVA calculations compared with Hashizume<br />

experimental data<br />

Reliability and risk analysis<br />

The following reliability and risk activities are performed within programmes promoted by international<br />

organisations.<br />

Ageing probability safety assessment. An official agreement has been signed between <strong>ENEA</strong> and the<br />

Institute for Energy (IE) of the Joint Research Centre (JRC) of the European Commission, in Petten,<br />

[B1.23] K. Hashizume et al., J. Nucl. Mater. 275, 277-286 (1999); and N. Davidovich, Validation of the ASTEC code fuel volatilization model on<br />

the Hashizume et al. experiments - SARNET-ST-P20 (2006)<br />

[B1.24] W. Plumecocq and G. Guillard, ELSA 2.1, ASTEC-V1/DOC/04-02 (2002); and N. Davidovich, Progress on synthesis modelling of UO 2<br />

oxidation - SARNET-ST-P5, <strong>ENEA</strong> Internal Report FIS–P9G1–001 (2005)<br />

[B1.25] W. Plumecocq and G. Guillard, ASTEC V1.2 code ELSA module, ASTEC-V1/DOC/05-06 (2006)<br />

References<br />

111<br />

Progress Report 2006


B1 R&D on Nuclear Fission<br />

B Fission Technology<br />

Netherlands, for participation in an international collaboration denoted as Network on Incorporating<br />

Ageing Effects into Probabilistic Safety Assessment. The network is devoted to developing reliability<br />

and availability models of systems and components, incorporating the effects of aging, and is<br />

expected to last till 2009.<br />

During 2006 a study on the impact of ageing on passive systems and their performance was<br />

undertaken, in addition to the definitions of basic ageing probabilistic safety assessment (APSA)<br />

reliability models.<br />

Passive system reliability. The activities performed mainly addressed issues related to passive<br />

systems relying on natural circulation to accomplish their functions:<br />

• development of an approach for integrating the passive systems within an accident sequence in<br />

combination with active systems and human actions in a probabilistic risk assessment (PRA)<br />

framework, based on fault tree and event tree techniques;<br />

• development of a preliminary reliability physics model based on the fracture mechanics approach<br />

to get the performance bounds to meet the reliability targets;<br />

• evaluation of uncertainties associated with passive system reliability;<br />

• risk study of a decay heat removal system based on failure mode, effects and critical analysis<br />

(FMECA);<br />

• participation in the IAEA Co-ordinated Research Project (CRP), denoted as “Natural circulation<br />

phenomena, modelling and reliability of passive systems that utilise the natural circulation”,<br />

launched in 2004. In this framework an activity aimed at the reliability assessment of the<br />

Argentinean integral-type CAREM-like reactor passive features has been undertaken and results<br />

are expected at the beginning of the 2007.<br />

B1.4 Nuclear Data<br />

General quantum mechanics<br />

Scattering by PT-symmetric non-local potentials. Non-local potentials play an important role in<br />

many applications of quantum scattering theory. In nuclear physics, they naturally arise from the<br />

convolution of an effective nucleon-nucleon interaction with the density of a target nucleus. In<br />

particular, a solvable non-local potential was proposed by Yamaguchi in 1954 in order to describe<br />

bound and scattering states of the proton-neutron system. The present study was focussed on the<br />

scattering properties of a PT-symmetric 1D version of the Yamaguchi potential, i.e., a non-Hermitian<br />

potential invariant under the product of the parity operator P and the time reversal operator T, but<br />

not under the separate actions of P and T: the transmission and reflection coefficients are worked<br />

out by the Green’s function method and show aspects of unitarity breaking quite different from those<br />

of PT-symmetric local potentials. The method of solution can be applied to large families of non-local<br />

potentials with separable kernel and different behaviour under P and T transformations.<br />

Group theory approach to transparent potentials. One-dimensional potentials with<br />

transmission coefficients equal to one over the whole real axis occur in several domains of general<br />

quantum mechanics: for instance, non-trivial reflectionless potentials can be derived by<br />

supersymmetric techniques from the null potential, which is trivially reflectionless, or they can be<br />

extracted by Lie-algebraic methods from the Casimir invariants of some non-compact groups. In the<br />

present study the latter technique was applied to derivation of the general form of real potentials<br />

appearing in Hamiltonians with underlying so(2,2) symmetry, which permits the solution of the<br />

corresponding Schrödinger equation in terms of hypergeometric functions. The six-generator<br />

so(2,2) algebra admits several decomposition chains and the corresponding potentials are, in<br />

general, not transparent: reflectionless potentials are obtained in the so(2,2) → so(2,1) → so(2)<br />

reduction chain when the solutions belong to discrete series representations of the so(2,1) sub-<br />

Progress Report 2006<br />

112


algebra appearing in the reduction. Hyperbolic potentials of the Pöschl-Teller type belong to this class. The<br />

Inönü-Wigner contraction of so(2,2) to the pseudo-euclidean algebra e(2,1) yields solutions that are always<br />

connected with reflectionless potentials. For the sake of simplicity, but without loss of generality, the<br />

general form has been worked out for reflectionless potentials appearing in Hamiltonians with underlying<br />

e(1,1) symmetry, where e(1,1) is a three-generator sub-algebra of e(2,1). The well-known reflectionless<br />

potential V(x) ~ 1/x 2 belongs to this class.<br />

Nuclear reaction theory and experiments<br />

Neutron-induced fission of light actinides. Within<br />

the work programme of theoretical activities of interest<br />

to the n_TOF collaboration, a model has been<br />

proposed to describe the coarse-grained resonant<br />

structure in neutron-induced fission of light actinides at<br />

sub-barrier excitation energies. The fission barriers are<br />

either two-, or three-humped, depending on the<br />

fissioning nucleus, and have an imaginary component<br />

in the second (isomeric) well, simulating a partial<br />

damping of class II vibrational states, while class III<br />

states, corresponding to excitations in the third well,<br />

are not damped. The sets of discrete transition states<br />

include rotational bands built either on vibrational states<br />

or on non-collective states. In the present<br />

phenomenological version of the model, energies and<br />

quantum numbers of transition states are not evaluated by means of a nuclear structure model, but are<br />

adjusted on the experimental (n,f) cross sections, which can thus be reproduced with great accuracy, as<br />

shown in figure B1.44, relative to the first-chance fission of 232 Th.<br />

The present fission model has been incorporated in Version 19 (Lodi) of the EMPIRE-II code of nuclear<br />

reactions, freely distributed by the National Nuclear Data Center, Brookhaven National Laboratory.<br />

Measurements of neutron-capture cross sections at the n_TOF facility at CERN. After the end of<br />

the experimental campaign in 2004, the two subsequent years were dedicated to analysis of capture<br />

cross-section measurements and to publication of related papers, such as those on 232 Th(n,γ) in the<br />

unresolved resonance region up to 1 MeV, 151 Sm(n,γ) in the energy range from 0.6 eV to 1 MeV, and<br />

209 Bi(n,γ) in the resolved resonance region, already summarised in the <strong>ENEA</strong> UTS FIS 2005 Progress<br />

Report. The new analysis completed and published in 2006 concerns the 207 Pb(n,γ) reaction in the<br />

resolved resonance region. The measurement was performed with an optimised set up of two C 6 D 6<br />

scintillator detectors, which permits reduction of scattered neutron background down to a negligible level,<br />

by using the pulse height weighting technique. Resonance parameters and radiative kernels were<br />

determined for 16 resonances in the neutron energy range from 3 to 320 keV. Good agreement with<br />

previous measurements is found at low energies, while substantial discrepancies appear beyond 45 keV.<br />

Maxwellian averaged cross sections were determined with an accuracy of ± 5%.<br />

Cross section (barns)<br />

0.15<br />

0.10<br />

0.05<br />

0<br />

Current work<br />

2002 Shcherbakov<br />

1991 Fursov<br />

1986 Kanda<br />

1983 Meadows<br />

1982 Behrens<br />

1978 Blons<br />

1975 Blons<br />

1.0 1.5 2.0 2.5<br />

Incident energy (MeV)<br />

Fig. B1.44 – 232 Th(n,f) near the fission threshold.<br />

Solid line: present work. Experimental data are<br />

taken from EXFOR<br />

Nuclear data processing and validation<br />

The cooperation between the <strong>ENEA</strong> Nuclear Data Group and the Organisation for Economic Co-operation<br />

and Development/Nuclear Energy Agency (OECD/NEA) Data Bank (Issy-les-Moulineaux, France)<br />

continued, in particular, within the Joint Evaluated Fission and Fusion (JEFF) Working Group on Benchmark<br />

Testing, Data Processing and Evaluations. Several technical feedbacks were notified, dedicated to the<br />

JEFF-3.1 European evaluated data files and their related processing through the NJOY nuclear data<br />

processing system. A valuable collaboration with a specialist formerly working at the Institute of Physics<br />

and Power Engineering (IPPE) Obninsk (Russian Federation) has been continued and extended.<br />

113<br />

Progress Report 2006


B1 R&D on Nuclear Fission<br />

B Fission Technology<br />

VITJEFF31.BOLIB and MATJEFF31.BOLIB generation. The VITJEFF31.BOLIB and<br />

MATJEFF31.BOLIB coupled n-γ multi-group cross-section libraries for nuclear fission applications in<br />

the VITAMIN-B6 American library energy group structure (199 neutron groups + 42 photon groups)<br />

were completely reprocessed by means of a version of the NJOY-99.112 nuclear data processing<br />

system, modified at <strong>ENEA</strong>. The present libraries, based on the JEFF-3.1 European evaluated<br />

nuclear data files, were previously produced through the NJOY-99.90 system, but it was decided to<br />

reprocess them completely after a detailed analysis of the list of modifications introduced by the<br />

author in the recent NJOY–99.112 version. The THERMR and GROUPR modules of this latter<br />

version were further modified at <strong>ENEA</strong>. In particular, a correction patch was prepared and<br />

introduced in the THERMR module of NJOY-99.112 in order to solve a problem that emerged in the<br />

processing of the JEFF-3.1 bound nuclides C (graphite) and Be (beryllium metal), where infinite loop<br />

calculations were generated. A second relevant correction patch was prepared for the GROUPR<br />

module of NJOY–99.112. The OECD/NEA Data Bank checked this patch and got positive results<br />

and then diffused it freely. This initiative was taken in order to extend the group-wise data processing<br />

capability to the evaluated data files including non-Cartesian interpolation schemes for secondary<br />

neutron energy distributions (MF=5). The <strong>ENEA</strong> Nuclear Data Group proved that 69 JEFF-3.1<br />

evaluated files could not be processed correctly through the GROUPR module of NJOY-99.112 or<br />

through all previous NJOY versions officially released, as communicated to the NJOY User Group.<br />

This set of data files contains, in particular, secondary neutron energy distributions (MF=5),<br />

presented as arbitrary tabulated functions (LF=1) with the non-Cartesian unit base interpolation law<br />

INT=22. The GROUPR module cannot process correctly the mentioned evaluated files because the<br />

GETSED subroutine cannot deal with secondary neutron energy distributions with non-Cartesian<br />

interpolation schemes (INT=11-15 and INT=21-25). Thus, the group-to-group scattering matrices<br />

for the MT=16, 17, 22, 28, 32, 33, 91 reactions could not be produced in the GENDF output cross<br />

section files of the 69 evaluated data files under consideration. The GROUPR problems described<br />

above were autonomously identified, starting from analysis of unacceptably underestimated K eff<br />

results obtained with criticality neutron transport calculations, performed through the XSDRNPM 1D<br />

discrete ordinates module of the SCAMPI data processing system. Two ICSBEP (2004 Edition) fast<br />

criticality benchmark experiments with 233 U (included in the previously cited 69–file set) were<br />

simulated. The results obtained with the XSDRNPM code in the P5-S16 approximation were<br />

obtained from JEFF-3.1 data, processed differently with the original GROUPR module of<br />

NJOY–99.112 and with the GROUPR version modified at <strong>ENEA</strong> into the 199 neutron energy group<br />

structure of the VITAMIN-B6 library. The results obtained with these deterministic transport<br />

calculations were compared with the results obtained through the MCNP-4C Monte Carlo code<br />

using JEFF-3.1 continuous-energy cross-section sets.<br />

181 materials were processed: 175 for standard isotopes or natural elements and 6 for bound<br />

nuclides. In the last group of materials, in particular, the H-Zr material was added to the set of 5<br />

bound nuclide materials contained in the VITAMIN-B6 library. Only one material ( 46 Ca from<br />

JEFF–3.1) could not be processed correctly. <strong>ENEA</strong> notified the OECD/NEA Data Bank of the fact<br />

that the total and elastic cross-section values of the first officially released version of this 46 Ca file<br />

below 1 keV, i.e., in the energy range 1.0×10 -05 - 1.0×10 03 eV, are set to zero, while capture crosssection<br />

values differ from zero.<br />

SCAMPI revision and updating. Many corrections and modifications were required for several<br />

modules of the SCAMPI data processing system in order to process the JEFF-3.1 data for the<br />

VITJEFF31.BOLIB library. In particular, the AJAX, MALOCS and SMILER modules were corrected.<br />

The most interesting modification was made to SMILER and MALOCS in order to take into account<br />

also the delayed component part (MF=5 and MT=455) of the fission spectrum, needed to obtain,<br />

e.g., more correct results in fixed-source transport calculations. On the contrary, the original version<br />

of SMILER can read only the prompt component (MF=6 and MT=18).<br />

The following versions of the MALOCS module were compared, as taken from the SCAMPI nuclear<br />

data processing and SCALE nuclear safety calculation systems:<br />

• original version of MALOCS in the SCAMPI distributed by OECD/NEA Data Bank;<br />

Progress Report 2006<br />

114


• version of MALOCS/SCAMPI as modified by <strong>ENEA</strong>, called MALOCS/SCAMPI Bologna version;<br />

• original version of MALOCS included in SCALE-4;<br />

• original most recent updated version of MALOCS included in SCALE-5.<br />

From the performance and feature comparison of the versions of MALOCS included in the SCAMPI,<br />

SCALE-4 and SCALE-5 systems, the following conclusions were drawn:<br />

• MALOCS/SCAMPI, MALOCS/SCALE-4 and MALOCS/SCALE-5 exclude the possibility of fission matrix<br />

collapsing.<br />

• MALOCS/SCALE-4 and MALOCS/SCALE-5 include the possibility to truncate the up-scatter crosssection<br />

terms with options IOPT7=0, 1, 2, 3.<br />

• MALOCS/SCAMPI includes only IOPT7=0.<br />

• MALOCS/SCALE-5 is similar to MALOCS/SCALE-4, but it is rewritten in FORTRAN-90.<br />

MALOCS/SCAMPI Bologna version includes the possibility of fission matrix collapsing and permits<br />

truncation of the up-scatter terms with options IOPT7=0, 1, 2, 3. Taking into account both these<br />

conclusions and the fact that the SCAMPI system includes functional modules all programmed in<br />

FORTRAN-77, as for the MALOCS/SCAMPI Bologna version, it was preferred to avoid any potential<br />

inconsistency in programming languages; therefore, this version was selected for the production of the<br />

new BUGJEFF31.BOLIB collapsed working library from the multi-group general-purpose<br />

VITJEFF31.BOLIB library in AMPX format. The GENDF cross-section files, obtained through a modified<br />

version of GROUPR in NJOY-99.112, were used to generate VITJEFF31.BOLIB and MATJEFF31.BOLIB.<br />

Extensive validation of the VITJEFF31.BOLIB library was performed through simulation of the same thermal<br />

and fast-neutron criticality benchmarks, already prepared for VITJEF22.BOLIB. The results obtained with<br />

the XSDRNPM 1D transport module of SCAMPI were compared with the results of Monte Carlo<br />

calculations using the MCNP-4C code.<br />

BUGJEFF31.BOLIB. Two preliminary versions (with and without up-scatter) of the cross-section working<br />

library BUGJEFF31.BOLIB were collapsed from the VITJEFF31.BOLIB library in AMPX format, generated<br />

with the <strong>ENEA</strong> modified version of NJOY-99.112. This collapsing work was done by means of the <strong>ENEA</strong><br />

revised SCAMPI system and, in particular, the modified version of the MALOCS module. The<br />

BUGJEFF31.BOLIB working library for shielding and light water reactor (LWR) pressure vessel dosimetry<br />

applications has the same group structure (47 n + 20 γ) and general features as the BUGLE-96 American<br />

library. To complete the response function cross section collapsing in the BUGLE-96 neutron group<br />

structure (47 n) from the most recent IAEA Reactor Dosimetry File IRDF-2002, a new tabulated weighting<br />

function was obtained from XSDRNPM calculations in the 1/4T (T=PWR pressure vessel thickness) spatial<br />

position, using the VITJEFF31.BOLIB multi-group library. The calculation chain was completely prepared<br />

but, before starting the collapsing procedure to generate the final working library, further investigation will<br />

be necessary to identify the inconsistencies and inaccuracies of the BUGLE-96 input data, which emerged<br />

in 2005 in the <strong>ENEA</strong> feasibility analysis for a BUGLE-type library generation.<br />

Computer code development<br />

BOT3P is a set of standard FORTRAN-77 language codes developed by the <strong>ENEA</strong> Nuclear Data Group in<br />

1997. The BOT3P Version 1.0 was originally conceived as a set of standard FORTRAN-77 language<br />

programmes in order to give the users of the DORT and TORT deterministic transport codes (both included<br />

in the Oak Ridge National Laboratory [ORNL USA] DOORS package) some useful diagnostic tools to<br />

prepare and check their input data files for both Cartesian and cylindrical geometries, including mesh grid<br />

generation modules, graphical display and utility programs for post-processing applications. Later versions<br />

extended the possibility to produce the geometrical, material distribution and fixed neutron source data to<br />

other deterministic transport codes such as TWODANT/THREEDANT (both included in the Los Alamos<br />

National Laboratory [LANL] USA DANTSYS package), PARTISN (the updated parallel version of DANTSYS)<br />

and the sensitivity code SUSD3D (distributed by the OECD/NEA Data Bank, Issy-les-Moulineaux, France)<br />

and, potentially, to any transport code through BOT3P binary output files that can be easily interfaced (see,<br />

115<br />

Progress Report 2006


B1 R&D on Nuclear Fission<br />

Fig. B1.45 – Simulation in Cartesian coordinates of a<br />

complex geometry (120X, 88Y, 200Z)<br />

B Fission Technology<br />

e.g., the case of the 2D and 3D discrete-ordinates<br />

neutron, photon and charged particle transport<br />

codes KASKAD-S-2.5 and KATRIN-2.0, developed<br />

at the Keldysh Institute of Applied Mathematics<br />

Moscow, Russian Federation). Since BOT3P binary<br />

output files can be easily interfaced, users can<br />

potentially produce the geometrical and material<br />

distribution data for any transport code starting from<br />

the same BOT3P input. This makes it possible to<br />

compare directly for the same geometry the effects on<br />

transport analysis results, which stem from the use of<br />

different data libraries and solution approaches.<br />

BOT3P Version 5.1 was completed in 2006 and has been freely available from the OECD/NEA Data<br />

Bank (F) since August 2006. This new version contains important additions specifically addressing<br />

radiation transport analysis for medical applications. The new module CATSM allows users to<br />

reduce the geometrical size of problems related to processed (already interpreted by physicians or<br />

by proper software) computerised (axial) tomography (CT/CAT) scans with or without small detail<br />

loss with respect to the original voxelized geometry. This permits problem sizes that can be more<br />

easily managed by transport codes. CATSM can automatically generate tetrahedron mesh grids,<br />

too, starting from the input voxelized geometry, even though the implemented algorithm is still rather<br />

rough and to be improved in the future. BOT3P-5.1 contains new graphics capabilities that enable<br />

users to visualise tetrahedron mesh grids in 3D and 2D cuts. As from Version 5.0, a general method<br />

to conserve mass of geometrically complex material zones simulated on both Cartesian and<br />

cylindrical mesh grids was implemented. BOT3P allows users to specify as refined a computation<br />

as desired of the possible area/volume error of material zones due to the stair-cased geometry<br />

representation, and automatically corrects material densities in order to conserve masses globally.<br />

BOT3P can store on binary outputs the detailed material zone distribution map inside each cell of<br />

the mesh grid, according to a sub-mesh grid refinement defined in input by the user and the<br />

area/volume fraction distribution of the different material zones contained in meshes at zone<br />

interfaces. This procedure allows a local (per cell) density correction as an alternative to the<br />

approach of a uniform density correction on the whole zone domain and potentially makes it<br />

possible to perform material zone homogenisation locally and transport analyses with more<br />

accuracy. BOT3P allows users to model X-Y, X-Z, Y-Z, R-Θ and R-Z geometries in two dimensions<br />

and X-Y-Z and R-Θ-Z geometries in three dimensions. BOT3P was successfully used not only in<br />

some complex neutron shielding and criticality benchmarks, but also in power reactor applications<br />

(Westinghouse AP1000 internals heating rate distribution calculations by Ansaldo Nucleare). BOT3P<br />

is designed to run on most Linux/UNIX platforms. The plot of figure B1.45 gives an idea of the<br />

complex modelling capabilities of BOT3P.<br />

Radioactive ion-beam production for nuclear-structure studies<br />

Intense neutron-rich isotope beams open many new fields of investigation, such as nuclear-structure<br />

studies, in a yet unexplored region. Several laboratories are trying to produce high enough intensities<br />

to warrant a new generation of experiments. The Study for the Production of Exotic Species (SPES)<br />

project is an accelerator-based facility for the production of intense neutron-rich radioactive ion<br />

beams, in the range of masses between 80 and 160. SPES is a new-generation ISOL facility<br />

proposed in Italy at the Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro (INFN-<br />

LNL), able to represent a competitive intermediate step between the existing facilities and the longer<br />

range high-performance EURISOL.<br />

Progress Report 2006<br />

116


Fig. B1.46 – Target configuration for the SPES project<br />

Window<br />

UCx disks<br />

Carbon dump<br />

The target system is one of the key issues for<br />

such facilities. A target configuration has<br />

been developed, in an <strong>ENEA</strong>/INFN-LNL<br />

collaboration, consisting of a 40-MeV proton<br />

beam (0.2 mA) directly impinging on the<br />

fission materials, composed of uranium carbide (UC x ). The 238 U fission fragments constitute the source for<br />

the exotic beams and, in order to extract them, the target is placed inside a graphite box at 2000°C. The<br />

target is split into several thin disks to allow cooling of the system by thermal radiation (fig. B1.46). In this<br />

way ∼10 13 fissions s -1 are obtained with a relatively simple system and at relatively low cost. All the main<br />

parameters of the system have been analysed by means of calculation codes: the fission rates and fission<br />

fragment distribution; power deposition and the thermo-mechanical behaviour of the disks.<br />

Proton<br />

beam<br />

B1.5 TRIGA RC-1 and RSV TAPIRO Plant-Operation for<br />

Application Development<br />

The availability of the TRIGA RC-1 and RSV TAPIRO plants has permitted <strong>ENEA</strong> to acquire solid experience<br />

in the development and management of research nuclear reactors and their application in programmes<br />

that use ionizing radiation sources, in particular for the qualification of radiation damage to materials. With<br />

the qualified TRIGA RC-1 neutron beams it is possible to develop highly technological neutron radiography<br />

and tomography techniques by means of thin scintillator films in lithium fluoride. The neutron tomography<br />

system located on the thermal column of the TRIGA reactor has been maintained in operation as a<br />

propaedeutic to the installation of a new collimator in the TRIGA tangential channel to improve the L/D ratio<br />

in a neutron flux of 10 8 n cm -2 s -1 .<br />

The TRIGA RC-1 and TAPIRO reactors have been proposed as experimental support to the newgeneration<br />

nuclear reactors that are nearing commercialisation (e.g., AP 1000) in order to check critical<br />

components under thermal and fast neutron flux. In fact, the TRIGA core flexibility permits installation of an<br />

experimental loop to continuously verify component performance under irradiation.<br />

During 2006 the TRIGA and TAPIRO reactors operated for about 2000 h. The TAPIRO irradiation column<br />

was also modified to permit boron neutron capture therapy (BNCT) for human brain tumour and melanoma<br />

applications (see sect. B2.1).<br />

117<br />

Progress Report 2006


B2 Medical, Energetic and Environmental<br />

Applications<br />

B Fission Technology<br />

B2.1 Boron Neutron Capture Therapy<br />

In 2006 construction of the epithermal column EPIMED at the TAPIRO experimental nuclear reactor<br />

was completed. The irradiation bunker to be used for beam characterisation was constructed and<br />

the doses outside the bunker, both in and outside the reactor hall, were measured and compared<br />

with calculations. A network of national groups involved in measuring the beam has been<br />

established to coordinate the beam characterisation. Support equipment for BNCT clinical trials has<br />

been acquired from the Swedish BNCT project (Hammercap S.p.A.).<br />

The collaborative activity with the Study and Production of Exotic Species (SPES)-BNCT project of<br />

the Legnano National Laboratory (LNL) of INFN and the University of Padua on using the thermal<br />

column HYTHOR at TAPIRO in radiobiological and micro-dosimetric studies continued. HYTHOR<br />

was also used for film irradiation in a collaboration with the University of Bremen (Germany) and for<br />

the development of gel dosimeters (University of Milan). A collaboration with INFN Pavia and cofinanced<br />

by the Ministry of Higher Education and Research (MIUR) was launched to study the<br />

application of BNCT to lung tumours.<br />

Design of a graphite configuration in the thermal column of the TRIGA reactor is under way. The<br />

objective is to repeat the clinical experimentation carried out on an explanted liver at Pavia. Extensive<br />

support in this activity has been provided by INFN Pavia.<br />

The epithermal column EPIMED at TAPIRO<br />

Human tissue has a relatively high tolerance to epithermal neutrons (in the BNCT context between<br />

about 1 eV and 10 keV) which, unlike thermal neutrons, are able to penetrate some centimetres into<br />

the tissue. However as the energy increases into the tens and hundreds of keV region the tolerance<br />

Normalised neutron flux/unit<br />

lethargy (cm-2 s-1)<br />

1×10 0<br />

1×10-2<br />

"Epithermal" spectrum<br />

Flux-to-Sievert rf (ICRP74)<br />

1×10-4<br />

1×10-8 1×10-6 1×10-4 1×10-2 1×10 0 1×10 2<br />

Energy (MeV)<br />

Fig. B2.1 – Comparison of epithermal neutron spectrum at TAPIRO<br />

with a flux-to-sievert conversion factor<br />

strongly decreases. Figure B2.1<br />

compares the epithermal neutron<br />

spectrum at TAPIRO with the<br />

ICRP74 flux-to-sievert conversion<br />

coefficient. Although this coefficient<br />

is for stochastic doses, whilst in<br />

therapy much higher systematic<br />

doses are involved, this comparison<br />

illustrates the critical importance of<br />

designing and measuring the<br />

neutron spectrum.<br />

The different phases of assembling<br />

the moderator and reflector are<br />

shown in figure B2.2. The mounted<br />

Progress Report 2006<br />

118


Fig. B2.2 - Mounting the moderator and reflector<br />

of EPIMED in TAPIRO<br />

column outside and inside the<br />

reactor (in the latter case<br />

without the lithiated<br />

polyethylene end neutron<br />

shield) is shown in figure B2.3.<br />

EPIMED provides a neutron<br />

beam that directly enters the<br />

reactor hall. The necessary<br />

beam shielding consists of<br />

Fig. B2.3 – The mounted column outside and<br />

firstly a bunker of limited<br />

inside the reactor<br />

volume appropriate for beam<br />

characterisation with the<br />

reactor operating at a maximum 10% of nominal power and secondly an<br />

irradiation room for patient therapy with the reactor at nominal power<br />

(5 kW). The bunker has been designed and constructed and the doses<br />

around the bunker in the reactor hall as well as outside the reactor hall<br />

have been measured and compared with the predicted values.<br />

Figure B2.4 shows a plan diagram of the bunker together with access maze and the shielding placed<br />

outside the reactor hall. As the present shielding configuration is temporary, to save money and time, it has<br />

been necessary to establish an exclusion zone outside the reactor hall in the direction of the neutron beam<br />

(fig. B2.4).<br />

The bunker shielding is composed of<br />

standard (assumed density<br />

2.3 g cm –3 ) 50-cm-thick concrete<br />

blocks (so referring to figure B2.4 there<br />

are two lines of concrete of total<br />

thickness 1 m in the direction of the<br />

control room). In addition the inner<br />

walls of both the bunker and the first<br />

part of the access maze are lined with<br />

Lawn<br />

Fence<br />

External<br />

concrete<br />

shielding<br />

Sliding door<br />

Reactor hall<br />

Entrance maze<br />

bunker<br />

43<br />

41<br />

42<br />

Fig. B2.4 – Plan of bunker, access maze and<br />

shielding outside the reactor hall and<br />

exclusion zone (showing some of the points<br />

used for dose comparison)<br />

Cooling<br />

system<br />

room<br />

Control<br />

room<br />

Air-lock<br />

119<br />

Progress Report 2006


B2 Medical, Energetic and<br />

B Fission Technology<br />

Fig. B2.5 – Construction of the<br />

characterisation bunker and access<br />

maze<br />

Fig. B2.6 – The completed characterisation bunker and access maze<br />

borated polyethylene to reduce the production of<br />

high-energy prompt gamma rays as well as<br />

activation. The ceiling is borated polyethylene just<br />

over 10 cm thick covered by a thin layer of iron. As<br />

a result, gamma rays from neutron capture in 10 B<br />

provide quite high doses above the ceiling.<br />

However at ground level the doses resulting from<br />

reflection of these gammas from the walls and roof<br />

of the reactor hall are relatively low. Figure B2.5<br />

shows various stages in the construction of the<br />

bunker, whilst figure B2.6 shows the completed<br />

bunker.<br />

The measured and calculated doses outside the<br />

bunker are in reasonable agreement. As an<br />

example, from [B2.1], figures B2.4 and B2.7 report<br />

15<br />

12<br />

14 13<br />

(SR1)<br />

11<br />

Reactor hall<br />

9-10<br />

7<br />

6<br />

8<br />

(SR2)<br />

2<br />

3<br />

4<br />

5<br />

1<br />

Fig. B2.7 – Points for dose comparison, measurement/<br />

calculation (see also fig. B2.4)<br />

Control room<br />

Progress Report 2006<br />

120


Environmental Applications<br />

Table B2.I – Comparison of selected measured and<br />

calculated doses (see also figs. B2.7 and B2.4)<br />

Point Gamma Dose (µSv/h) Neutron Dose(µSv/h)<br />

Meas. Calc. Meas. Calc.<br />

1 1.3 1.2 1.3 1.2<br />

2 1.2 0.68 1.1 0.59<br />

3 3.3 1.2 3.3 1.0<br />

4 2.3 1.7 1.5 1.1<br />

5 1.6 1.2 1.6 0.95<br />

6 5.3 1.8 1.6 0.55<br />

7 35.3 7.3 1.6 1.0<br />

8 0.9 0.79 1.3 1.0<br />

9 1.7 3.1 3 1.8<br />

10 39 2.6 2.2<br />

11 32 15 26 44<br />

12 21 6.9 5 2.0<br />

13 55 17 9 22<br />

14 48 25 10 28<br />

15 2.6 1.4 1.4 1.8<br />

41 1.2 0.44 0.3 0.14<br />

42 0.6 0.47 0.2 0.11<br />

43 0.9 0.34 0.1 0.10<br />

µSv/h<br />

5.000E+2<br />

Fig. B2.8 – Calculated total dose map in the reactor hall<br />

at about 1 m above the floor<br />

comparisons for selected dose points within<br />

the reactor hall and outside the hall at the<br />

margins of the limited access. The<br />

comparison between calculated and<br />

measured doses is shown in table B2.I.<br />

Where the comparison is poor (e.g., point 7) the reason is known (in this case an unavoidable averaging<br />

of the calculated dose over a volume that includes the concrete shielding as well as air). Having established<br />

a degree of confidence on the calculated doses, it is possible consider the dose maps (e.g., in figure B2.8)<br />

of the total (neutron and gamma) doses in the reactor hall at about 1 m above the floor.<br />

Employment of the thermal column HYTHOR at TAPIRO<br />

The thermal neutron experimental facility HYTHOR, designed by the LNL-INFN Padua, has been used by<br />

LNL to carry out micro-dosimetric studies by means of specially designed tissue-equivalent proportional<br />

counters (TEPCs). HYTHOR has also been utilised by the University of Padua for mouse irradiation in the<br />

context of research into boron compounds for skin melanoma. Again in the BNCT framework, films for<br />

neutron capture radiography have been irradiated in collaboration with the University of Bremen.<br />

In collaboration with the Department of Physics of Milan University, Monte Carlo calculations were<br />

compared with experimental results by means of gel dosimeters in order to investigate a) the spatial<br />

distribution of the gamma dose and thermal neutron fluence and b) the accuracy at which the boron<br />

concentration should be estimated in an explanted organ of a BNCT patient.<br />

Study of BNCT applied to lung tumours<br />

A collaboration has started with the multi-disciplinary group at INFN Pavia, previously involved in the<br />

treatment of the explanted liver, to study the application of BNCT to lung tumours. Calculations concerning<br />

[B2.1]<br />

K.W. Burn, L. Casalini, E. Nava, Confronto tra calcoli e misure relativo al monitoraggio d’area del reattore TAPIRO per la caratterizzazione<br />

della nuova colonna epitermica (EPIMED), <strong>ENEA</strong> Internal Report in preparation<br />

References<br />

121<br />

Progress Report 2006


B2 Medical, Energetic and<br />

Fig. B2.9 – Plan view a) and vertical cross section b) of the<br />

TRIGA reactor core and thermal column with phantom<br />

B Fission Technology<br />

Fig. B2.10 – Plan view of the TRIGA reactor<br />

analytical and voxel phantoms are being carried out,<br />

employing the neutron beam from EPIMED.<br />

Measurements will be made on a lung model<br />

phantom placed in the EPIMED beam.<br />

Design of a facility at TRIGA to treat<br />

explanted livers<br />

This activity was initiated in 2006 with the support of<br />

INFN Pavia. A different thermal column [B2.2] to the<br />

original one used for liver irradiation [B2.3] was<br />

suggested by Pavia. The modified configuration has<br />

the advantage of not requiring the liver to be rotated<br />

by 180° during treatment. The MCNP model of TRIGA<br />

at <strong>ENEA</strong> Casaccia [B2.4] was improved in the vicinity<br />

of the thermal column and all the radial and tangential<br />

experimental ducts were included. The new thermal<br />

column design [B2.2] was incorporated with a liver<br />

phantom [B2.3] and container (including a partial<br />

screening layer of lithium fluoride to harden the<br />

neutron spectrum) supplied by Pavia. The resulting<br />

configuration is shown in figures B2.9 and B2.10.<br />

The distribution of the therapeutic 10 B dose in the<br />

phantom was calculated to verify that the graphite<br />

configuration (fig. B2.9) together with the lithium<br />

fluoride spectrum modifier gave a therapeutic dose<br />

covering the whole phantom. An example of such a<br />

distribution is shown in figure B2.11 (from the Pavia<br />

TRIGA model, courtesy of the Department of Nuclear<br />

and Theoretical Physics, University of Pavia and INFN,<br />

Pavia). Figure B2.12 shows an axial profile of the<br />

therapeutic dose along the central axis.<br />

Dose (arb.units)<br />

12<br />

8<br />

4<br />

Boron dose distribution 2 nd z mesh<br />

Fig. B2.11 – Typical qualitative distribution of<br />

therapeutic dose within liver phantom (courtesy<br />

of Department of Nuclear and Theoretical<br />

Physics, University of Pavia and INFN, Pavia)<br />

0<br />

10<br />

5<br />

0<br />

-5<br />

5<br />

10<br />

-10 -10<br />

-5 0<br />

Axial mesh No<br />

Radial mesh No<br />

Progress Report 2006<br />

122


Environmental Applications<br />

Fig. B2.12 – Typical profile of the 10 B dose in the phantom along the axis<br />

of the thermal column<br />

28<br />

26<br />

Whilst results for the distribution of the dose within the phantom<br />

agree quite closely with those obtained at the Pavia TRIGA, the<br />

absolute values of the doses differ considerably. The differences<br />

arise because lead is used as a gamma shield at Casaccia, while<br />

bismuth is used at Pavia, and masonite is present in the thermal<br />

column at Casaccia (some modelling differences are also evident).<br />

A first conclusion is that the therapeutic doses at Casaccia will not<br />

be very much larger than those at Pavia, notwithstanding the fact<br />

that the nominal reactor power is four times higher at Casaccia than<br />

at Pavia.<br />

Dose (arb. units)<br />

24<br />

22<br />

20<br />

18<br />

16<br />

14<br />

410 415 420 425 430 435<br />

Axial mesh No<br />

B2.2 Solar Thermal Energy<br />

Experimental activities under the Solar Thermal<br />

Energy Project are aimed at evaluating the<br />

behaviour of several kinds of structural material<br />

in stagnant molten nitrate environments. In<br />

particular, the corrosion mechanism/rate and<br />

weld resistance have been evaluated.<br />

The experimental facility (fig. B2.13) is made up<br />

of eight crucibles (fig. B2.14), coated inside with<br />

Ti, in which the specimens are inserted (or<br />

extracted) by means of a special device<br />

(fig. B2.15). Each crucible is equipped with its<br />

own heater and electronic control system for<br />

monitoring and acquiring pressure and<br />

temperature.<br />

Fig. B2.13 – View of the experimental facility, special device<br />

for introducing/extracting specimens and the monitoring<br />

acquisition system<br />

Tests were carried out on austenitic steel (AISI<br />

321H). In selecting the specimen geometry the<br />

type of test was taken into account: simple<br />

rectangular slabs for the corrosion mechanism<br />

tests and corrosion rate evaluation; rectangular<br />

welding slabs for evaluation of the tungsten inert<br />

gas (TIG) weld resistance in molten salt. The<br />

tests were performed in a nitrate mixture of<br />

sodium and potassium (40 wt.% NaNO 3 –<br />

60 wt.% KNO 3 ).<br />

Fig. B2.14 – External and internal view of the crucibles<br />

[B2.2] S. Bortolussi, Neutron flux distribution in liver at the Pavia reactor, presented at the Workshop on Innovative Treatment Concepts for<br />

Liver Metastases (University Hospital Essen 2006)<br />

[B2.3] S. Bortolussi, TAOrMINA: una originale configurazione del campo neutronico per una migliore uniformità della dose nell’organo<br />

espiantato, degree thesis, Department of Physics, University of Trieste (2002-2003)<br />

[B2.4] N. Burgio et al., MCNP model of the 1 MW TRIGA MARK II at <strong>ENEA</strong> Casaccia, <strong>ENEA</strong> Internal Report FIS-P815-017 (2005)<br />

References<br />

123<br />

Progress Report 2006


B2 Medical, Energetic and<br />

Fig. B2.15 – Special device for<br />

introducing/extracting specimens<br />

B Fission Technology<br />

The procedure followed was to<br />

compare the pre- and post-test<br />

analyses: visual inspection, surface<br />

area and roughness measurement,<br />

weight, x-ray analysis (only for the<br />

welded specimens). In the post-test<br />

analysis the optical microscopy<br />

(scanning electron microscopy and energy dispersive x-ray spectroscopy) analysis was taken into<br />

account. The static tests ended after 8000 h at 590°C.<br />

B2.3 Development Activities for Antarctic Drilling<br />

Talos Dome is an ice dome (72°48’S; 159°06’E, 2316 m) on the edge of the East Antarctic plateau<br />

and adjacent to the Victoria Land Mountains in the western Ross Sea area. The firn core<br />

temperature is -41°C, and average snow accumulation over the last eight centuries is 80 kg/m 2 /yr.<br />

Airborne radar measurements indicate that the dome summit is situated above sloping bedrock (ice<br />

thickness 1880 ± 25 m ), but there is relatively flat bedrock 5-6 km distant along the SE ice divide<br />

(ID1 159°11’00”E, 72°49’40”S, 2315 m), about 770 ± 25 m in elevation and covered by<br />

1545 ± 25 m of ice (fig. B2.16).<br />

Wilkes Subglacial Basin<br />

Weddel Sea<br />

Legend<br />

Core site<br />

Wind direction<br />

Main ice divide<br />

10m contour line<br />

Rock outcrop<br />

Byrd<br />

0 1000 2000<br />

km<br />

Southern Ocean<br />

290 km<br />

Reeves<br />

Glacier<br />

Kohnen<br />

Berken Island<br />

Ross Sea<br />

Terra Nova<br />

Bay Station<br />

Dome Fuji<br />

Vostok<br />

Dome C<br />

Talos Dome<br />

Ross Sea<br />

Ice thickness (m):<br />

ID1=1545 ± 25m<br />

TD summit=1880 ± 25m<br />

1940000<br />

1940000<br />

1935000<br />

1935000<br />

1930000<br />

1925000<br />

North (m)<br />

1930000<br />

1925000<br />

North (m)<br />

1920000<br />

1920000<br />

Southern Ocean<br />

Law<br />

Dome<br />

Dome C<br />

EPICA<br />

Vostok<br />

500<br />

0<br />

1100 km<br />

TD Summit<br />

1915000<br />

1910000<br />

TD<br />

Summit<br />

1915000<br />

1910000<br />

550 km Ross<br />

Taylor<br />

Sea<br />

Dome<br />

1500 km<br />

km<br />

Siple<br />

Dome<br />

Talos<br />

Dome<br />

Bedrock elevation (WGS84 m):<br />

ID1= 770 ± 25m<br />

TD summit=440±25m<br />

ID1<br />

ID1<br />

1905000<br />

1905000<br />

1900000<br />

1900000<br />

495000<br />

490000<br />

490000<br />

505000<br />

500000<br />

500000<br />

495000<br />

515000<br />

510000<br />

505000<br />

525000<br />

520000<br />

East (m)<br />

515000<br />

510000<br />

East (m)<br />

530000<br />

530000<br />

525000<br />

520000<br />

Fig. B2.16 – Talos Dome<br />

geographic position<br />

Progress Report 2006<br />

124


Environmental Applications<br />

Fig. B2.17 – Talos Dome remote camp<br />

Sleeping and storages<br />

Snow for water<br />

Camp fuel<br />

Drilling at Talos Dome should greatly increase<br />

knowledge about the response of nearcoastal<br />

sites to climate changes and the<br />

Holocene history of accumulation rates in the<br />

Ross Sea region. In addition, this ice record<br />

will strongly contribute to understanding the<br />

last glacial-interglacial transition when<br />

different climatic features and trends are<br />

observed between West-East Antarctica<br />

(Byrd, Vostok, EPICA-Dome C, Dome Fuji,<br />

Law Dome) and two near-coastal sites in the<br />

Ross Sea sector (Taylor and Siple Dome).<br />

Lastly it would give an idea of the future<br />

variability of accumulation and dynamic<br />

changes in this sensitive area.<br />

Runway and<br />

TO fuel<br />

-600<br />

-650<br />

-700<br />

Science trench and<br />

drill generator<br />

Main generator and living<br />

Cargo line<br />

29/11/06 START OF THE SEASON: -600.84M<br />

3 Dec. 1° week: 32.49 m, -633.29 m<br />

Problem with PLC-Inverter Stop 6-7 Dec.<br />

10 Dec. 2° week: 52.04 m, -685.44 m<br />

Trench<br />

entrance<br />

The Talos Dome Ice (TALDICE) project is<br />

currently drilling to bedrock at the ID1 site,<br />

and one glacial/interglacial period of usable<br />

record is expected. The project is also aimed<br />

at developing integrated instrumentation in<br />

order to improve the Italian capability to drill<br />

and measure the ice core and to plan and<br />

manage both the mechanical parts and the<br />

electronic control system of the new<br />

perforation system.<br />

The project started in the field in November<br />

2004. In this first season one French and four<br />

Italian technicians and a scientist were<br />

involved for about 50 days in drilling activities<br />

and in setting up a temporary field camp<br />

(summer camp), using the vehicles, modules<br />

and tents of the International Trans Antarctic<br />

Scientific Expedition (ITASE) programme<br />

(fig. B2.17).<br />

During the second season, from November<br />

2005 to January 2006, for about 80 days<br />

eleven technicians and scientists (3 French<br />

and 8 Italian) were involved in TALDICE<br />

activity. The camp was opened on 7<br />

Fig. B2.18 – Perforation progress graph season 2006-2007<br />

November. The first 40 days of the season<br />

were dedicated to re-building the roof of the<br />

perforation trench and setting up both the drill facilities inside the trench and the camp infrastructures.<br />

During the first drilling season from 17 December 2005 to 15 January 2006 the final depth of -607.74 m<br />

was reached, equal to ~7500 years ago. The ice cores to 480 m depth were analysed by a dielectric<br />

profiling instrument, then cut, put in plastic bags, packed in boxes and sent to Europe for further analyses.<br />

The camp for the second campaign of perforation (fig. B2.18) was opened on 7 November 2006 during<br />

Depth (m)<br />

-750<br />

-800<br />

-850<br />

-900<br />

-950<br />

-1000<br />

-1050<br />

-1100<br />

-1150<br />

-1200<br />

-1250<br />

-1300<br />

26 Dec. M1 motor problem<br />

power generator problem<br />

31 Dec. 5° week: 117.83 m, -1098.54 m<br />

7 Jan. 6° Week: 122.30m, -1220.84m<br />

17 Dec. 3° week: 146.10 m, -831.64 m<br />

11 Jan. end drill season: -1293.86 m<br />

Logged Depth: -1300.58 m<br />

24 Dec. 4° week: 149.17 m, -980.71 m<br />

25 Dec. Christmas day off<br />

01 Jan. new year day off<br />

29/11/2006<br />

01/12/2006<br />

03/12/2006<br />

05/12/2006<br />

07/12/2006<br />

09/12/2006<br />

11/12/2006<br />

13/12/2006<br />

15/12/2006<br />

17/12/2006<br />

19/12/2006<br />

21/12/2006<br />

23/12/2006<br />

25/12/2006<br />

27/12/2006<br />

29/12/2006<br />

31/12/2006<br />

02/01/2007<br />

04/01/2007<br />

06/01/2007<br />

08/01/2007<br />

10/01/2007<br />

12/01/2007<br />

14/01/2007<br />

125<br />

Progress Report 2006


B2 Medical, Energetic and<br />

B Fission Technology<br />

Fig. B2.19 – 27 December 2006: 1000 m of perforation<br />

Fig. B2.20 – Tephra Layers<br />

Table B2.II – Perforation season 2006-2007 final data<br />

Start perforation 29 November 2006<br />

End perforation 11 January 2007<br />

Duration of perforation<br />

36 useful days<br />

Logged depth<br />

1300.58 m<br />

Drilling depth<br />

1293.86 m<br />

Drilling length this season 693 m<br />

Packed, cut and sent depth 486 m (from 478.00 to 666.00 m<br />

from 1001.00 to 1300.00 m)<br />

Liquid level end of season<br />

(density=0.958 g cm -3 ) 109 m<br />

Daily average<br />

19.25 m<br />

Average liquid/m<br />

17.41 m<br />

Run number 386<br />

Core length average/run 1.79 m<br />

Total recovered chips ice 4950 kg (7 kg chips/m)<br />

Perforation hours<br />

501 h<br />

Core length average/<br />

perforation hours<br />

1.37 m/h<br />

Progress Report 2006<br />

126


Environmental Applications<br />

the ongoing Antarctic Campaign (2006-2007). The drilling season was started on 29 November and will<br />

terminate 11 January 2007, with the final depth of –1300.58 m, corresponding to approxi mately 60,000<br />

to 80,000 years ago. The original objective, 1200 m, has been surpassed, meaning that all the ice covering<br />

the last deglaciation and the end of the last glaciation is up at the surface. The material will be studied in<br />

the laboratories of the European countries (Italy, France, German, Switzerland and UK) involved in the<br />

project (fig. B2.19).<br />

The visible tephra layers observed during this season total 35, of which 10 are particularly dense<br />

(fig. B2.20). These layers will be very useful for getting one exact dating of the ice extracted during<br />

perforation. Table B2.II reports the final data of the 2006-2007 perforation season. The Antarctic bed rock,<br />

situated at a depth of approximately-1550 m should be reached during the next perforation campaign<br />

2007-2008.<br />

127<br />

Progress Report 2006


B3 Participation in International Working Groups<br />

and Associations<br />

B Fission Technology<br />

In relation to <strong>ENEA</strong>’s institutional role as the national focal point and advisor for nuclear-energyrelated<br />

scientific and technological issues, the department ensures that <strong>ENEA</strong> (and Italy as a whole)<br />

is represented in the principal committees and bodies concerned with the pacific use of nuclear<br />

energy, at national (Ministry of Economic Development [MSE]) and international (Nuclear Energy<br />

Agency [NEA], International Atomic Energy Agency [IAEA], Euratom, etc.) levels. Representatives<br />

and experts from the department are present in nearly all the NEA standing committees (NSC, NDC,<br />

CSNI, RWMC, CRPPH) as well as in the steering committees, and in a number of IAEA permanent<br />

Table B3.I - Bilateral agreements<br />

Scientific & Technological<br />

Agency/Institution<br />

Commissariat à l’Energie Atomique (CEA)<br />

Forschungszeuntrum Karlsruhe (FZK)<br />

Oak Ridge National Laboratory (ORNL)<br />

Belgian Nuclear Research Centre (SCK-CEN)<br />

Joint Research Centre - Institute for Transuranium<br />

Elements (JRC-ITU)<br />

Paul Scherrer Institute (PSI)<br />

Seoul National University (SNU)<br />

Institut Laue-Langevin (ILL)<br />

Institute of Mathematics and Mechanics,<br />

Ural branch of the Russian Academic of Science<br />

(IMM-RAS)<br />

Country<br />

FRANCE<br />

GERMANY<br />

USA<br />

BELGIUM<br />

EUROPEAN COMMISSION<br />

SWITZERLAND<br />

SOUTH KOREA<br />

FRANCE<br />

RUSSIA<br />

Progress Report 2006<br />

128


technical working groups (TWGs), for example, on fast reactors, advanced technologies for light water<br />

reactors, on fuel performance and technology, etc. Finally, a senior researcher of the department acts as<br />

national delegate in the Consultative Committee Euratom-Fission (CCE-Fission).<br />

The department also administers several bilateral agreements with major international organisations (see<br />

table B3.I) in the nuclear fission field to ensure that R&D activities of common interest are performed<br />

synergically.<br />

Field of Co-operation<br />

Thematic area<br />

Nuclear fission<br />

Accelerator–driven systems &<br />

transmutation<br />

Advanced fission reactors<br />

Accelerator–driven systems<br />

Accelerator–driven systems<br />

and partitioning and transmutation<br />

Spallation neutron sources<br />

Nuclear fission<br />

Irradiation in high flux reactors<br />

Nuclear and conventional<br />

accident analysis<br />

Physics, safety, technologies and<br />

code developments for nuclear<br />

reactors<br />

Fuel cycle strategies, transmutation<br />

systems and HLM Technologies<br />

Experimental testing, computer<br />

simulations, design and<br />

performance of advanced reactors<br />

Physics and technologies for ADS<br />

ADS technologies and advanced<br />

fuels<br />

Physics and HLM technologies<br />

HLM technologies<br />

Nuclear Instrumentation, diagnostics<br />

and materials<br />

Exp. measurements, computer<br />

simulations and code developments<br />

129<br />

Progress Report 2006


B4 Publications<br />

B Fission Technology<br />

Articles<br />

B4.1 Publications<br />

R&D on Nuclear Fission<br />

C. HELLWIG, M. STREIT, P. BLAIR, F.C. KLAASSEN, R.P.C. SCHRAM, F. VETTRAINO, T. YAMASHITA: Inert<br />

matrix fuel behaviour in test irradiations<br />

J. Nucl. Mater. 352, 291-299 (2006)<br />

M. STREIT, T. TVERBERG, W. WIESENACK, F. VETTRAINO: Inert matrix and thoria fuel irradiation at an<br />

international research reactor<br />

J. Nucl. Mater. 352, 263-267 (2006)<br />

F. BIANCHI, C. ARTIOLI, K.W. BURN, G. GHEPARDI, S. MONTI, L. MANSANI, L. CINOTTI, D. STRUWE, M.<br />

SCHIKORR, W. MASACHEK, H.A. ABDERRAHIM, D. DE BRUYN, G. RIMPAULT: Status and trend of core<br />

design activities for heavy metal cooled accelerator driven system<br />

Energy Convers. Manage. 47, 2698-2709 (2006)<br />

S. ANDRIAMONJE, S. AUNE, G. BAN, S. BREAUD, C. BLANDIN, E. FERRER, B. GESLOT, A. GIGANON,<br />

I. GIOMATARIS, C. JAMMES, Y. KADI, P. LABORIE, J.F. LECOLLEY, J. PANCIN, M. RAILLOR, R. ROSA, L.<br />

SARCHIAPONE, J.C. STECKMEYER, J. TILLER: New neutron detector based on micromegas technology<br />

for ADS project<br />

Nucl. Intrum. Method A562, 755-759 (2006)<br />

G. BENAMATI, A. GESSI, P.-Z. ZHANG: Corrosion experiments in flowing LBE at 450°C<br />

J. Nucl. Mater. 356, 1-3, 198-202 (2006)<br />

C. FOLETTI, G. SCADDOZZO, M. TARANTINO, A. GESSI, G. BERTACCI, P. AGOSTINI, G. BENAMATI:<br />

<strong>ENEA</strong> experience in LBE technology<br />

J. Nucl. Mater. 356, 1-3, 264-272 (2006)<br />

P. AGOSTINI, L. SANSONE, G. BENAMATI, C. PETROVICH, S. MONTI: Neutronic and thermo-mechanic<br />

calculations for the design of the TRADE spallation target<br />

Nucl. Instrum. Method Phys. Res. 562, 849-854 (2006)<br />

A. MATHIS, S. MONTI: Energia nucleare: l’opzione del futuro; prima e seconda parte<br />

Termotecnica, Marzo N. 36-Aprile N.58 (2006)<br />

L. BURGAZZI, R. FERRI, B. GIANNONE: Safety assessment of a liquid target<br />

Nucl. Eng. Des. 236, 4, 359-367 (2006)<br />

Progress Report 2006<br />

130


L. BURGAZZI: Probabilistic safety analysis of an accelerator-lithium target based experimental facility<br />

Nucl. Eng. Des. 236, 12, 1264-1274 (2006)<br />

F. CANNATA, A. VENTURA: Scattering by PT-symmetric non-local potentials<br />

Czech. J. Phys. 56, 943-951 (2006)<br />

G. A. KERIMOV, A. VENTURA: Group-theoretical approach to reflectionless potentials<br />

J. Math. Phys. 47, 082108, 1-16 (2006)<br />

M. SIN, R. CAPOTE, A. VENTURA, M. HERMAN, P. OBLOŽINSKY: Fission of light actinides: 232 Th(n,f) and<br />

231 Pa(n,f) reactions<br />

Phys. Rev. C 74, 014608, 1-13 (2006)<br />

G. AERTS, U. ABBONDANNO, H. ALVAREZ, F. ALVAREZ-VELARDE, S. ANDRIAMONJE, J. ANDRZEJEWSKI, P.<br />

ASSIMAKOPULOS, L. AUDOUIN, G. BADUREK, P. BAUMANN, F. BEČVÁR, E. BERTHOUMIEUX, F. CALVIÑO, D.<br />

CANO-OTT, R. CAPOTE, A. CARRILLO DE ALBORNOZ, P. CENNINI, V. CHEPEL, E. CHIAVERI, N. COLONNA, G.<br />

CORTES, A. COUTURE, J. COX, M. DAHLFORS, S. DAVID, I. DILLMAN, R. DOLFINI, C. DOMINGO-PARDO, W.<br />

DRIDI, I. DURAN, C. ELEFTHERIADIS, M. EMBID-SEGURA, L. FERRANT, A. FERRARI, R. FERREIRA-MARQUES,<br />

L. FITZPATRICK, H. FRAIS-KOELBL, K. FUJII, W. FURMAN, I. GONCALVES, E. GONZALEZ-ROMERO, A.<br />

GOVERDOSKI, F. GRAMEGNA, E. GRIESMAYER, C. GUERRERO, F. GUNSING, B. HAAS, R. HAIGHT, M. HEIL,<br />

A. HERRERA-MARTINEZ, M. IGASHIRA, S. ISAEV, E. JERICHA, Y. KADI, F. KÄPPELER, D. KARADIMOS, D.<br />

KARAMANIS, M. KERVENO, V. KETLEROV, P. KOEHLER, V. KONOVALOV, E. KOSSIONIDES, M. KRTIČKA, C.<br />

LAMBOUDIS, H. LEEB, A. LINDOTE, I. LOPES, M. LOZANO, S. LUKIC, J. MARGANIEC, L. MARQUES, S.<br />

MARRONE, P. MASTINU, A. MENGONI, P.M. MILAZZO, C. MOREAU, M. MOSCONI, F. NEVES, H.<br />

OBERHUMMER, S. O’BRIEN, M. OSHIMA, J. PANCIN, C. PAPACHRISTODOULOU, C. PAPADOPOULOS, C.<br />

PARADELA, N. PATRONIS, A. PAVLIK, P. PAVLOPOULOS, L. PERROT, M. T. PIGNI, R. PLAG, A. PLOMPEN, A.<br />

PLUKIS, A. POCH, C. PRETEL, J. QUESADA, T. RAUSCHER, R. REIFARTH, M. ROSETTI, C. RUBBIA, G.<br />

RUDOLF, P. RULLHUSEN, J. SALGADO, L. SARCHIAPONE, I. SAVVIDIS, C. STEPHAN, G. TAGLIENTE, J.L. TAIN,<br />

L. TASSAN-GOT, L. TAVORA, R. TERLIZZI, G. VANNINI, P. VAZ, A. VENTURA, D. VILLAMARIN, M. C. VINCENTE,<br />

V. VLACHOUDIS, R. VLASTOU, F. VOSS, S. WALTER, H. WENDLER, M. WIESCHER AND K. WISSHAK (The<br />

n_TOF Collaboration): Neutron capture cross section of 232 Th measured at the n_TOF facility at CERN in the<br />

unresolved resonance region up to 1 MeV<br />

Phys. Rev. C 73, 054610, 1-10 (2006)<br />

S. MARRONE, U. ABBONDANNO, G. AERTS, F. ALVAREZ-VELARDE, H. ALVAREZ-POL, S. ANDRIAMONJE, J.<br />

ANDRZEJEWSKI, G. BADUREK, P. BAUMANN, F. BEČVÁR, J. BENLLIURE, E. BERTHOMIEUX, F. CALVIÑO, D.<br />

CANO-OTT, R. CAPOTE, P. CENNINI, V. CHEPEL, E. CHIAVERI, N. COLONNA, G. CORTES, D. CORTINA, A.<br />

COUTURE, J. COX, S. DABABNEH, M. DAHLFORS, S. DAVID, R. DOLFINI, C. DOMINGO-PARDO, I. DURAN-<br />

ESCRIBANO, M. EMBID-SEGURA, L. FERRANT, A. FERRARI, R. FERREIRA-MARQUES, H. FRAIS-KOELBL, K.<br />

FUJII, W. I. FURMAN, R. GALLINO, I. F. GONCALVES, E. GONZALEZ-ROMERO, A. GOVERDOVSKI, F.<br />

GRAMEGNA, E. GRIESMAYER, F. GUNSING, B. HAAS, R. HAIGHT, M. HEIL, A. HERRERA-MARTINEZ, S. ISAEV,<br />

E. JERICHA, F. KÄPPELER, Y. KADI, D. KARADIMOS, M. KERVENO, V. KETLEROV, P. E. KOEHLER, V.<br />

KONOVALOV, M. KRTIČKA, C. LAMBOUDIS, H. LEEB, A. LINDOTE, M. I. LOPES, M. LOZANO, S. LUKIC, J.<br />

MARGANIEC, J. MARTINEZ-VAL, P. F. MASTINU, A. MENGONI, P. M. MILAZZO, A. MOLINA-COBALLES, C.<br />

MOREAU, M. MOSCONI, F. NEVES, H. OBERHUMMER, S. O’BRIEN, J. PANCIN, T. PAPAEVANGELOU, C.<br />

PARADELA, A. PAVLIK, P. PAVLOPOULOS, J. M. PERLADO, L. PERROT, M. PIGNATARI, M. T. PIGNI, R. PLAG,<br />

A. PLOMPEN, A. PLUKIS, A. POCH, A. POLICARPO, C. PRETEL, J. M. QUESADA, S. RAMAN, W. RAPP, T.<br />

RAUSCHER, R. REIFARTH, M. ROSETTI, C. RUBBIA, G. RUDOLF, P. RULLHUSEN, J. SALGADO, J. C. SOARES,<br />

C. STEPHAN, G. TAGLIENTE, J. L. TAIN, L. TASSAN-GOT, L. M. N. TAVORA, R. TERLIZZI, G. VANNINI, P. VAZ, A.<br />

VENTURA, D. VILLAMARIN-FERNANDEZ, M. VINCENTE-VINCENTE, V. VLACHOUDIS, F. VOSS, H. WENDLER,<br />

M. WIESCHER AND K. WISSHAK (The n_TOF Collaboration): Measurement of the 151 Sm(n,γ) cross section from<br />

0.6 eV to 1 MeV via the neutron time-of-flight technique at the CERN n_TOF facility<br />

Phys. Rev. C 73, 034604, 1-18 (2006)<br />

131<br />

Progress Report 2006


B4 Publications<br />

B Fission Technology<br />

C. DOMINGO-PARDO, U. ABBONDANNO, G. AERTS, H. ÁLVAREZ-POL, F. ALVAREZ-VELARDE, S.<br />

ANDRIAMONJE, J. ANDRZEJEWSKI, P. ASSIMAKOPOULOS, L. AUDOUIN, G. BADUREK, P. BAUMANN,<br />

F. BEČVÁR, E. BERTHOUMIEUX, F. CALVIÑO, D. CANO-OTT, R. CAPOTE, A. CARRILLO DE ALBORNOZ,<br />

P. CENNINI, V. CHEPEL, E. CHIAVERI, N. COLONNA, G. CORTES, A. COUTURE, J. COX, M. DAHLFORS,<br />

S. DAVID, I. DILLMAN, R. DOLFINI, W. DRIDI, I. DURAN, C. ELEFTHERIADIS, M. EMBID-SEGURA, L.<br />

FERRANT, A. FERRARI, R. FERREIRA-MARQUES, L. FITZPATRICK, H. FRAIS-KOELBL, K. FUJII, W.<br />

FURMAN, R. GALLINO, I. GONCALVES, E. GONZALEZ-ROMERO, A. GOVERDOVSKI, F. GRAMEGNA, E.<br />

GRIESMAYER, C. GUERRERO, F. GUNSING, B. HAAS, R. HAIGHT, M. HEIL, A. HERRERA-MARTINEZ, M.<br />

IGASHIRA, S. ISAEV, E. JERICHA, Y. KADI, F. KÄPPELER, D. KARAMANIS, D. KARADIMOS, M. KERVENO,<br />

V. KETLEROV, P. KOEHLER, V. KONOVALOV, E. KOSSIONIDES, M. KRTIČKA, C. LAMBOUDIS, H. LEEB,<br />

A. LINDOTE, I. LOPES, M. LOZANO, S. LUKIC, J. MARGANIEC, L. MARQUES, S. MARRONE, P.<br />

MASTINU, A. MENGONI, P. M. MILAZZO, C. MOREAU, M. MOSCONI, F. NEVES, H. OBERHUMMER, M.<br />

OSHIMA, S. O’BRIEN, J. PANCIN, C. PAPACHRISTODOULOU, C. PAPADOPOULOS, C. PARADELA, N.<br />

PATRONIS, A. PAVLIK, P. PAVLOPOULOS, L. PERROT, R. PLAG, A. PLOMPEN, A. PLUKIS, A. POCH, C.<br />

PRETEL, J. QUESADA, T. RAUSCHER, R. REIFARTH, M. ROSETTI, C. RUBBIA, G. RUDOLF, P.<br />

RULLHUSEN, J. SALGADO, L. SARCHIAPONE, I. SAVVIDIS, C. STEPHAN, G. TAGLIENTE, J. L. TAIN, L.<br />

TASSAN-GOT, L. TAVORA, R. TERLIZZI, G. VANNINI, P. VAZ, A. VENTURA, D. VILLAMARIN, M. C.<br />

VINCENTE, V. VLACHOUDIS, R. VLASTOU, F. VOSS, S. WALTER, H. WENDLER, M. WIESCHER, AND K.<br />

WISSHAK (The n_TOF Collaboration): New measurement of neutron capture resonances in 209 Bi<br />

Phys. Rev. C 74, 025807, 1-10 (2006)<br />

C. DOMINGO-PARDO, U. ABBONDANNO, G. AERTS, H. ÁLVAREZ-POL, F. ALVAREZ-VELARDE, S.<br />

ANDRIAMONJE, J. ANDRZEJEWSKI, P. ASSIMAKOPOULOS, L. AUDOUIN, G. BADUREK, P. BAUMANN,<br />

F. BEČVÁR, E. BERTHOUMIEUX, S. BISTERZO, F. CALVIÑO, D. CANO-OTT, R. CAPOTE, C. CARRAPIC¸<br />

O,P. CENNINI, V. CHEPEL, E. CHIAVERI, N. COLONNA, G. CORTES, A. COUTURE, J. COX, M.<br />

DAHLFORS, S. DAVID, I. DILLMAN, R. DOLFINI, W. DRIDI, I. DURAN, C. ELEFTHERIADIS, M. EMBID-<br />

SEGURA, L. FERRANT, A. FERRARI, R. FERREIRA-MARQUES, L. FITZPATRICK, H. FRAIS-KOELBL, K.<br />

FUJII, W. FURMAN, R. GALLINO, I. GONCALVES, E. GONZALEZ-ROMERO, A. GOVERDOVSKI, F.<br />

GRAMEGNA, E. GRIESMAYER, C. GUERRERO, F. GUNSING, B. HAAS, R. HAIGHT, M. HEIL, A.<br />

HERRERA-MARTINEZ, M. IGASHIRA, S. ISAEV, E. JERICHA, Y. KADI, F. KÄPPELER, D. KARAMANIS, D.<br />

KARADIMOS, M. KERVENO, V. KETLEROV, P. KOEHLER, V. KONOVALOV, E. KOSSIONIDES, M. KRTIČKA,<br />

C. LAMBOUDIS, H. LEEB, A. LINDOTE, I. LOPES, M. LOZANO, S. LUKIC, J. MARGANIEC, S. MARRONE,<br />

P. MASTINU, A. MENGONI, P. M. MILAZZO, C. MOREAU, M. MOSCONI, F. NEVES, H. OBERHUMMER,<br />

M. OSHIMA, S. O’BRIEN, J. PANCIN, C. PAPACHRISTODOULOU, C. PAPADOPOULOS, C. PARADELA, N.<br />

PATRONIS, A. PAVLIK, P. PAVLOPOULOS, L. PERROT, R. PLAG, A. PLOMPEN, A. PLUKIS, A. POCH, C.<br />

PRETEL, J. QUESADA, T. RAUSCHER, R. REIFARTH, M. ROSETTI, C. RUBBIA, G. RUDOLF, P.<br />

RULLHUSEN, J. SALGADO, L. SARCHIAPONE, I. SAVVIDIS, C. STEPHAN, G. TAGLIENTE, J.L. TAIN, L.<br />

TASSAN-GOT, L. TAVORA, R. TERLIZZI, G. VANNINI, P. VAZ, A. VENTURA, D. VILLAMARIN, M. C.<br />

VINCENTE, V. VLACHOUDIS, R. VLASTOU, F. VOSS, S. WALTER, H. WENDLER, M. WIESCHER, AND K.<br />

WISSHAK (The n_TOF Collaboration): Resonance capture cross section of 207 Pb<br />

Phys. Rev. C 74, 055802, 1-6 (2006)<br />

R. ORSI: A general method of conserving mass in complex geometry simulations on mesh grids and its<br />

implementation in BOT3P5.0<br />

Nucl. Sci. Eng. 154, 247-259 (2006)<br />

J.J. KLINGENSMITH, Y.Y. AZMY, J.C. GEHIN, R. ORSI: Tort solutions to the three-dimensional MOX<br />

Benchmark, 3-D extension C5G7MOX<br />

Prog. Nucl. Energy 48, 445 455 (2006)<br />

E. BOTTA, R. ORSI: Westinghouse AP1000 internals heating rate distribution calculation using a 3-D<br />

deterministic transport method<br />

Nucl. Eng. Des. 236, 1558-1564 (2006)<br />

Progress Report 2006<br />

132


A. ANDRIGHETTO, C.M. ANTONUCCI, S. CEVOLANI, C.PETROVICH, M. SANTANA LEITNER: Multifoil UCx target<br />

for the SPES project - an update<br />

Europ. Phys. J. A 30, 591-601 (2006)<br />

L. BURGAZZI: Failure mode and effect analysis application for the safety and reliability analysis of a thermalhydraulic<br />

passive system<br />

Nucl. Technol. 156, 2, 150-158 (2006)<br />

Medical, Energetic and Environmental Applications<br />

K.W. BURN, C. DAFFARA, G. GUALDRINI, M. PIERANTONI, P. FERRARI: Treating voxel geometries in<br />

radiation protection dosimetry with a patched version of the Monte Carlo Codes MCNP and MCNPX<br />

Radiat. Prot. Dosim. doi:10.1093/rpd/ncl150, OUP (2006)<br />

Reports<br />

R&D on Nuclear Fission<br />

G. GLINATSIS: Safety aspects of the EFIT/MgO - Pb core, <strong>ENEA</strong> Internal Report FPN-P815-005 (2006)<br />

M. SAROTTO, C. ARTIOLI: Possible solutions for the neutronic design of the two zones EFIT-MgO/Pb core, <strong>ENEA</strong><br />

Internal Report FPN-P815-001(2006)<br />

M. SAROTTO, C. ARTIOLI, V. PELUSO: Preliminary neutronic analysis of the three zones EFIT-MgO/Pb core, <strong>ENEA</strong><br />

Internal Report FPN-P815-004 (2006)<br />

M. SAROTTO, C. ARTIOLI, V. PELUSO: MgO/Pb core neutronic preliminary analysis, <strong>ENEA</strong> Internal Report FIS-<br />

P815-021, EFIT (2006)<br />

P. MELONI: A Neutronics-thermal-hydraulics model for preliminary studies on TRADE dynamics, <strong>ENEA</strong> Internal<br />

Report FIS-P99R-006 (2006)<br />

G. BANDINI: Interpretation of TRIGA experimental data with SIMMER-III code for RELAP5 model evaluation and<br />

transient analysis, <strong>ENEA</strong> Internal Report FIS-P99R-007 (2006)<br />

G. BANDINI, P. MELONI: Analysis of BETHSY experiment 4.3b with ASTEC V1.2 code for CESAR thermalhydraulic<br />

module validation, <strong>ENEA</strong> Internal Report FPN-P9D0-001 (2006)<br />

G. BANDINI: ICARE/CATHARE calculation of the QUENCH-11 experiment in the frame of the IRSN participation<br />

in the SARNET benchmark, <strong>ENEA</strong> Internal Report FPN-P9D0-002 (2006)<br />

G. BANDINI: Analysis of the OECD LOFT fission product experiment LP-FP-2 with ASTEC V1.2.1 code, <strong>ENEA</strong><br />

Internal Report FPN-P9G1-001 (2006)<br />

G. BANDINI: Validation of CESAR thermal-hydraulic module of ASTEC V1.2 code on BETHSY experiments, <strong>ENEA</strong><br />

Internal Report FIS-P9D0-002 (2006)<br />

R. CAPONETTI: Determination by thermochemical calculation of speciation and deposition of fission product and<br />

structural material during the vercors HT 1 experiment, <strong>ENEA</strong> Internal Report FIS-P127-042 (2006)<br />

R. ORSI: BOT3P Version 5.1: two/three-dimensional mesh generator and graphical display of geometry and results<br />

for deterministic transport codes, <strong>ENEA</strong> Report RT/2006/34/FIS (2006)<br />

133<br />

Progress Report 2006


B4 Publications<br />

R. ORSI: BOT3P Version 5.1: a pre-post-processor system for transport analysis, <strong>ENEA</strong> Internal Report<br />

FIS-P9H6-014 Rev.0 (2006)<br />

B Fission Technology<br />

R. ORSI: CATSM: a pre-processor tool for medical applications, <strong>ENEA</strong> Internal Report FIS-P9H6-015 Rev.0<br />

(2006)<br />

S. CEVOLANI: Valutazione approssimata dell’effetto della frequenza di pulsazione del fascio sulla termica<br />

del target sottile per SPES, <strong>ENEA</strong> Internal Report FIS-P815-022 (2006)<br />

A. ANDRIGHETTO, C. ANTONUCCI, S. CEVOLANI, C. PETROVICH: <strong>ENEA</strong> contribution to the design of the<br />

thin target for the SPES project, <strong>ENEA</strong> Internal Report FIS-P815-020 (2006)<br />

S. CEVOLANI: Termica della camera del target lamellare per SPES, <strong>ENEA</strong> Internal Report FPN-P815-(2006)<br />

Medical, Energetic and Environmental Applications<br />

M. BASTA, E. NAVA, G. ROSI: Monitoraggio d’area del reattore TAPIRO. Proposta di modifica, <strong>ENEA</strong><br />

Internal Report FPN-TLE TAPIRO 06/02 (2006)<br />

Contributions to Conferences<br />

R&D on Nuclear Fission<br />

R. CALABRESE, F. VETTRAINO, T. TVERBERG: Inert matrix fuel modelling: transuranus analysis of the<br />

Halden IFA-652 first irradiation cycle<br />

Inter. Workshop on Materials Models and Simulation for Nuclear Fuels (MMSNF-5), Nice (France), June 1-<br />

2, 2006<br />

R. CALABRESE, F. VETTRAINO, T. TVERBERG: Low burn-up inert matrix fuels performance: transuranus<br />

analysis of the Halden IFA-652 first irradiation cycle<br />

14 th Inter. Conference on Nuclear Engineering (ICONE-14), Miami (USA), July 17-20, 2006<br />

S. BOURG, C. CARAVACA, E. WALLE, G. DE ANGELIS, R. MALMBECK, G.B. LEWIN, J. UHLIR, T. INOUE,<br />

V. LUCA: Pyrochemistry within EUROPART from the acquisition of basic data to the processes for the<br />

treatment of spent fuels<br />

9 th IEM on Actinide and Fission Product Partitioning and Transmutation, OECD Nuclear Energy Agency (9-<br />

IEMPT), Nimes (France), September 25-29, 2006<br />

C. MADIC, M. J. HUDSON, P. BARON, N. OUVRIER, C. HILL, F. ARNAUD, A. G. ESPARTERO, J.F.<br />

DESREUX, G. MODOLO, R. MALMBECK, S. BOURG, G. DE ANGELIS AND J. UHLIR: EUROPART.<br />

European research programme for partitioning of minor actinides within high active wastes issuing from the<br />

reprocessing of spent nuclear fuels. Some of the principal results obtained<br />

9 th IEM on Actinide and Fission Product Partitioning and Transmutation, OECD Nuclear Energy Agency (9-<br />

IEMPT), Nimes (France) September 25-29, 2006<br />

F. BIANCHI, R. FERRI: Accident analysis of the windowless target system<br />

Topical Meeting on Advances In Nuclear Analysis and Simulation (PHYSOR-2006), Vancouver (Canada),<br />

September 10-14, 2006<br />

F. BIANCHI, R. FERRI, V. MOREAU: Transient thermo-hydraulic analysis of the windowless target system<br />

for the lead bismuth eutectic cooled accelerator driven system<br />

14 th Inter. Conference on Nuclear Engineering (ICONE-14), Miami (USA), July 16-20, 2006<br />

Progress Report 2006<br />

134


P. AGOSTINI, M. CIOTTI, C. PETROVICH, M. CARTA, N. ELMI, L. SANSONE, D. BELLER, C. KRAKOWIAK, A.<br />

BERGERON: Target study for the RACE HP experiment<br />

14 th Inter. Conference on Nuclear Engineering (ICONE-14), Miami (USA), July 17-20, 2006<br />

P. AGOSTINI, M. CIOTTI, C. KRAKOWIAK, C. PETROVICH, G. BENAMATI, A. BERGERON, N. ELMI, G. GRANGET,<br />

L. SANSONE, M. SCHIKORR: Target study for the RACE HP experiment<br />

8 th Inter. Workshop on Spallation Materials Technology (IWSMT-8), Taos (USA), October 16-20, 2006<br />

M. CARTA, N. BURGIO, A. D’ANGELO, A. SANTAGATA, C. PETROVICH, M. SCHIKORR, D. BELLER, L. SAN<br />

FELICE, G. IMEL, M. SALVATORES: Electron versus proton accelerator driven sub-critical system performance<br />

using TRIGA reactors at power<br />

Topical Meeting on Advances In Nuclear Analysis and Simulation (PHYSOR-2006), Vancouver (Canada),<br />

September 10-14, 2006<br />

W. AMBROSINI, G. BENAMATI, S. CARNEVALI, C. FOLETTI, N. FORGIONE, F. ORIOLO, G. SCADDOZZO, M.<br />

TARANTINO: Experiments on gas injection enhanced circulation in a pool-type liquid metal apparatus<br />

XXIV Congresso Nazionale UIT, Napoli (Italy), June 21-23, 2006<br />

A. RENIERI: L’integrazione delle competenze nello sviluppo di sistemi nucleari innovativi<br />

Convegno L’uso pacifico dell’energia nucleare da Ginevra 1955 ad oggi: Il caso italiano,<br />

Rome (Italy), March 8–9, 2006<br />

A. RENIERI, S. MONTI: Le attività di R&S dell’<strong>ENEA</strong> nel contesto europeo ed internazionale del nuovo nucleare da<br />

fissione: sinergie e collaborazioni in Italia e all’estero<br />

Convegno Nazionale AEIT, Capri (Italy), September 16-20, 2006<br />

S. MONTI: IRIS integral test: experimental investigation of small break LOCAs in coupled vessel/containment<br />

integral reactors<br />

15 th IRIS Team Meeting, Pittsburgh (USA), April 25-27, 2006<br />

S. MONTI: IRIS activities in the framework of the Italian national program on nuclear fission<br />

16 th IRIS Team Meeting, Santander (Spain), November 7-9, 2006<br />

L. CINOTTI, C. FAZIO, J. KNEBEL, S. MONTI, H. AIT ABDERRAHIM, C. SMITH, K. SUH: LFR lead-cooled fast<br />

reactor<br />

Conference on EU Research and Training in Reactor Systems (FISA 2006), Kirchberg, Luxembourg, March 13-16,<br />

2006<br />

S. MONTI: Status and perspectives of Italian activities in the field of fast spectrum nuclear systems<br />

IAEA Technical Meeting on Review of National Programmes on Fast Reactors and Accelerator Driven Systems,<br />

39 th TWG-FR Annual Meeting (CIAE), Beijing (China), May 15-19, 2006<br />

S. MONTI: Planned R&D and technology activities in Italy for the development of the GENIV lead-cooled fast<br />

reactor<br />

IAEA Technical Meeting, Vienna (Austria), December 6-8, 2006<br />

P. MELONI: Overview of helium cooled system applications with RELAP at <strong>ENEA</strong><br />

2006 Inter. Congress on Advances in Nuclear Power Plant (ICAPP ’06), Reno (USA), June 4-8, 2006<br />

G. BANDINI, P. MELONI, N. TRÉGOURÈS, J. FLEUROT: Post-test analysis of the BETHSY experiment 9.1b with<br />

ASTEC V1.2 Code for CESAR thermal-hydraulic module validation<br />

NENE International Conference, Portoroz (Slovenia), September 18-21, 2006<br />

G. BANDINI, G. GUILLARD, J. FLEUROT: Participation in the SARNET benchmark: analysis of the QUENCH-11<br />

experiment with ICARE/CATHARE code<br />

12 th Inter. QUENCH Workshop, Forschungszentrum Karlsruhe (Germany), October 24-26, 2006<br />

135<br />

Progress Report 2006


B4 Publications<br />

S. EDERLI: <strong>ENEA</strong> activity in the WP9.3,<br />

SARNET CORIUM Topic 2 nd Annual Review Meeting, Villigen (Switzerland), January 30-31, 2006<br />

B Fission Technology<br />

G. REPETTO, S. EDERLI: Assessment of the heat transfer and late phase model of the ICARE/CATHARE<br />

code against debris bed in pile experiments<br />

18 th National & 7 th ISHMT-ASME Heat and Mass Transfer Conference, Guwahati (India), January 4-6, 2006<br />

L. BURGAZZI, M. MARQUES: Integration of passive system reliability in PSA studies<br />

14 th Inter. Conference on Nuclear Engineering (ICONE-14), Miami (USA), July 16-20, 2006<br />

L. BURGAZZI: Probabilistic design of a passive system<br />

2006 ANS Winter Meeting, Albuquerque (New Mexico), November 12-16, 2006<br />

L. BURGAZZI: Development of probability distributions of passive system failure<br />

3 rd Inter. Symposium on Systems & Human Science: Complex Systems Approaches for Safety, Security<br />

and Reliability (SSR 2006), Vienna (Austria), March 6-8, 2006<br />

L. BURGAZZI: Reliability aspects of passive systems<br />

EC Enlargement and Integration Workshop on Use of Probabilistic Safety Assessment (PSA) for Evaluation<br />

of Impact of Ageing Effects on the Safety of Nuclear Power Plants, Bucharest (Romania), October 2-4,<br />

2006.Invited talk<br />

L. BURGAZZI: Incorporation of ageing effects into component reliability and availability models<br />

Europ. Safety and Reliability Conference (ESREL ’06), Estoril (Portugal), September 18-22, 2006<br />

M. HEIL, U. ABBONDANNO, G. AERTS, H. ÁLVAREZ-POL, F. ALVAREZ-VELARDE, S. ANDRIAMONJE, J.<br />

ANDRZEJEWSKI, P. ASSIMAKOPOULOS, L. AUDOUIN, G. BADUREK, P. BAUMANN, F. BEČVÁŘ, E.<br />

BERTHOUMIEUX, S. BISTERZO, F. CALVIÑO, D. CANO-OTT, R. CAPOTE, C. CARRAPICO, P. CENNINI, V.<br />

CHEPEL,E. CHIAVERI, N. COLONNA, G. CORTES, A. COUTURE, J. COX, M. DAHLFORS, S. DAVID, I.<br />

DILLMAN, R. DOLFINI, CÉSAR DOMINGO PARDO, W. DRIDI, I. DURAN, C. ELEFTHERIADIS, M. EMBID-<br />

SEGURA, L. FERRANT, A. FERRARI, R. FERREIRA-MARQUES, L. FITZPATRICK, H. FRAIS-KOELBL, K.<br />

FUJII, W. FURMAN, R. GALLINO, I. GONCALVES, E. GONZALEZ-ROMERO, A. GOVERDOVSKI, F.<br />

GRAMEGNA, E. GRIESMAYER, C. GUERRERO, F. GUNSING, B. HAAS, R. HAIGHT, A. HERRERA-<br />

MARTINEZ, M. IGASHIRA, S. ISAEV, E. JERICHA, Y. KADI, F. KÄPPELER, D. KARAMANIS, D.<br />

KARADIMOS, M. KERVENO, V. KETLEROV, P. KOEHLER, V. KONOVALOV, E. KOSSIONIDES, M. KRTI ČKA,<br />

C. LAMBOUDIS, H. LEEB, A. LINDOTE, I. LOPES, M. LOZANO, S. LUKIC, J. MARGANIEC, S. MARRONE,<br />

P. MASTINU, A. MENGONI, P.M. MILAZZO, C. MOREAU, M. MOSCONI, F. NEVES, H. OBERHUMMER, M.<br />

OSHIMA, S. O’BRIEN, J. PANCIN, C. PAPACHRISTODOULOU, C. PAPADOPOULOS, C. PARADELA, N.<br />

PATRONIS, A. PAVLIK, P. PAVLOPOULOS, L. PERROT, R. PLAG, A. PLOMPEN, A. PLUKIS, A. POCH, C.<br />

PRETEL, J. QUESADA, T. RAUSCHER, R. REIFARTH, M. ROSETTI, C. RUBBIA, G. RUDOLF, P.<br />

RULLHUSEN, J. SALGADO, L. SARCHIAPONE, I. SAVVIDIS, C. STEPHAN, G. TAGLIENTE, J.L. TAIN, L.<br />

TASSAN-GOT, L. TAVORA, R. TERLIZZI, G. VANNINI, P. VAZ, A. VENTURA, D. VILLAMARIN, M. C.<br />

VINCENTE, V. VLACHOUDIS, R. VLASTOU, F. VOSS, S. WALTER, H. WENDLER, M. WIESCHER, K.<br />

WISSHAK (The n_TOF Collaboration): Neutron capture cross section measurements for nuclear<br />

astrophysics at n_TOF<br />

9 th Inter. Symposium on Nuclei in the Cosmos (NIC-IX), CERN (Geneva), June 25-30, 2006, SISSA<br />

Proceedings of Science (http://pos.sissa.it/), PoS (NIC-IX) 053<br />

M. MOSCONI, M. HEIL, F. KÄPPELER, R. PLAG, A. MENGONI, K. FUJII, R. GALLINO, G. AERTS,<br />

R.TERLIZZI, U. ABBONDANNO, H. ÁLVAREZ-POL, F. ALVAREZ-VELARDE, S. ANDRIAMONJE, J.<br />

ANDRZEJEWSKI, P. ASSIMAKOPOULOS, L. AUDOUIN, G. BADUREK, P. BAUMANN, F. BEČVÁŘ, E.<br />

BERTHOUMIEUX, S. BISTERZO, F. CALVIÑO, D. CANO-OTT, C. CARRAPIÇO, R. CAPOTE, P. CENNINI, V.<br />

CHEPEL, E. CHIAVERI, N. COLONNA, G. CORTES, A. COUTURE, J. COX, M. DAHLFORS, S. DAVID, I.<br />

DILLMAN, R. DOL NI, C. DOMINGO PARDO W. DRIDI, I. DURAN, C. ELEFTHERIADIS, M. EMBID-<br />

Progress Report 2006<br />

136


SEGURA, L. FERRANT, A. FERRARI, R. FERREIRA-MARQUES, L. FITZPATRICK, H. FRAIS-KOELBL, W.<br />

FURMAN, I. GONCALVES, E. GONZALEZ-ROMERO, A. GOVERDOVSKI, F. GRAMEGNA, E. GRIESMAYER, C.<br />

GUERRERO, F. GUNSING, B. HAAS, R. HAIGHT, A. HERRERA-MARTINEZ, M. IGASHIRA, S. ISAEV, E. JERICHA,<br />

Y. KADI, D. KARAMANIS, D. KARADIMOS, M. KERVENO, V. KETLEROV, P. KOEHLER, V. KONOVALOV, E.<br />

KOSSIONIDES, M. KRTI CKA, C. LAMBOUDIS, H. LEEB, A. LINDOTE, I. LOPES, M. LOZANO, S. LUKIC, J.<br />

MARGANIEC, S. MARRONE, P. MASTINU, P.M. MILAZZO, C. MOREAU, F. NEVES, H. OBERHUMMER, M.<br />

OSHIMA, S. O'BRIEN, J. PANCIN, C. PAPACHRISTODOULOU, C. PAPADOPOULOS, C. PARADELA, N.<br />

PATRONIS, A. PAVLIK, P. PAVLOPOULOS, L. PERROT, A. PLOMPEN, A. PLUKIS, A. POCH, C. PRETEL, J.<br />

QUESADA, T. RAUSCHER, R. REIFARTH, M. ROSETTI, C. RUBBIA, G. RUDOLF, P. RULLHUSEN, J. SALGADO,<br />

L. SARCHIAPONE, I. SAVVIDIS, C. STEPHAN, G. TAGLIENTE, J.L. TAIN, L. TASSAN-GOT, L. TAVORA, G.<br />

VANNINI, P. VAZ, A. VENTURA, D. VILLAMARIN, M. C. VINCENTE, V. VLACHOUDIS, R. VLASTOU, F. VOSS, S.<br />

WALTER, H. WENDLER, M. WIESCHER, K. WISSHAK (The n_TOF Collaboration): Experimental challenges for the<br />

Re/Os Clock<br />

9 th Inter. Symposium on Nuclei in the Cosmos (NIC-IX), CERN (Geneva), June 25-30, 2006, SISSA Proceedings<br />

of Science (http://pos.sissa.it/), PoS (NIC-IX) 055<br />

C. DOMINGO PARDO, U. ABBONDANNO, G. AERTS, H. ÁLVAREZ-POL, F. ALVAREZ-VELARDE6, S.<br />

ANDRIAMONJE, J. ANDRZEJEWSKI, P. ASSIMAKOPOULOS, L. AUDOUIN, G. BADUREK, P. BAUMANN, F.<br />

BEČVÁŘ, E. BERTHOUMIEUX, S. BISTERZO, F. CALVIÑO, D. CANO-OTT, R. CAPOTE, C. CARRAPIÇO, P.<br />

CENNINI, V. CHEPEL, E. CHIAVERI, N. COLONNA, G. CORTES, A. COUTURE, J. COX, M. DAHLFORS, S. DAVID,<br />

I. DILLMAN, R. DOLFINI, W. DRIDI, I. DURAN, C. ELEFTHERIADIS, M. EMBID-SEGURA, L. FERRANT, A.<br />

FERRARI, R. FERREIRA-MARQUES, L. FITZPATRICK, H. FRAIS-KOELBL, K. FUJII, W. FURMAN, R. GALLINO, I.<br />

GONCALVES, E. GONZALEZ-ROMERO, A. GOVERDOVSKI, F. GRAMEGNA, E. GRIESMAYER, C. GUERRERO, F.<br />

GUNSING, B. HAAS, R. HAIGHT, M. HEIL, A. HERRERA-MARTINEZ, M. IGASHIRA, S. ISAEV, E. JERICHA, Y.<br />

KADI, F. KÄPPELER, D. KARAMANIS, D. KARADIMOS, M. KERVENO, V. KETLEROV, P. KOEHLER0, V.<br />

KONOVALOV, E. KOSSIONIDES, M. KRTIČKA, C. LAMBOUDIS, H. LEEB, A. LINDOTE, I. LOPES, M. LOZANO, S.<br />

LUKIC, J. MARGANIEC, S. MARRONE, P. MASTINU, A. MENGONI, P.M. MILAZZO, C. MOREAU, M. MOSCONI,<br />

F. NEVES, H. OBERHUMMER, M. OSHIMA, S. O’BRIEN, J. PANCIN, C. PAPACHRISTODOULOU, C.<br />

PAPADOPOULOS, C. PARADELA, N. PATRONIS, A. PAVLIK, P. PAVLOPOULOS, L. PERROT, R. PLAG, A.<br />

PLOMPEN, A. PLUKIS, A. POCH, C. PRETEL, J. QUESADA, T. RAUSCHER, R. REIFARTH, M. ROSETTI, C.<br />

RUBBIA, G. RUDOLF, P. RULLHUSEN, J. SALGADO, L. SARCHIAPONE, I. SAVVIDIS, C. STEPHAN, G.<br />

TAGLIENTE, J.L. TAIN, L. TASSAN-GOT, L. TAVORA, R. TERLIZZI, G. VANNINI, P. VAZ, A. VENTURA, D.<br />

VILLAMARIN, M. C. VINCENTE, V. VLACHOUDIS, R. VLASTOU, F. VOSS, S. WALTER, H. WENDLER, M.<br />

WIESCHER, K. WISSHAK (The n_TOF Collaboration): Neutron capture measurements on the s-process<br />

termination isotopes, lead and bismuth<br />

9 th Inter. Symposium on Nuclei in the Cosmos (NIC-IX), CERN (Geneva), June 25-30, 2006, SISSA Proceedings<br />

of Science (http://pos.sissa.it/), PoS (NIC-IX) 058<br />

S. MARRONE, U. ABBONDANNO, G. AERTS, H. ÁLVAREZ, F. ALVAREZ-VELARDE, S. ANDRIAMONJE, J.<br />

ANDRZEJEWSKI, P. ASSIMAKOPOULOS, L. AUDOUIN, G. BADUREK, P. BAUMANN, F. BEČVÁŘ , E.<br />

BERTHOUMIEUX, F. CALVIÑO, D. CANO-OTT, R. CAPOTE, C. CARRAPIÇO, P. CENNINI, V. CHEPEL, E.<br />

CHIAVERI, N. COLONNA, G. CORTES, A. COUTURE, J. COX, M. DAHLFORS, S. DAVID, I. DILLMANN,<br />

R.DOLFINI, C. DOMINGO-PARDO, W. DRIDI, I. DURAN, C. ELEFTHERIADIS, M. EMBID-SEGURA, L. FERRANT,<br />

A. FERRARI, R. FERREIRA-MARQUES, L. FITZPATRICK, H. FRAIS-KOELBL, K. FUJII, W. FURMAN, R. GALLINO,<br />

I. GONCALVES, E. GONZALEZ-ROMERO, A. GOVERDOVSKI, F. GRAMEGNA, E. GRIESMAYER, C. GUERRERO,<br />

F. GUNSING, B. HAAS, R. HAIGHT, M. HEIL, A. HERRERA-MARTINEZ, M. IGASHIRA, S. ISAEV, E. JERICHA, Y.<br />

KADI, F. KÄPPELER, D. KARAMANIS, D. KARADIMOS, M. KERVENO, V. KETLEROV, P. KOEHLER, V.<br />

KONOVALOV, E. KOSSIONIDES, M. KRTIČKA, C. LAMBOUDIS, H. LEEB, A. LINDOTE, I. LOPES, M. LOZANO, S.<br />

LUKIC, J. MARGANIEC, P. MASTINU, A. MENGONI, P.M. MILAZZO, C. MOREAU, M. MOSCONI, F. NEVES, H.<br />

OBERHUMMER, S. O'BRIEN, M. OSHIMA, J. PANCIN, C. PAPACHRISTODOULOU, C. PAPADOPOULOS , C.<br />

PARADELA, N. PATRONIS, A. PAVLIK, P. PAVLOPOULOS, L. PERROT, M. PIGNATARI, R. PLAG, A. PLOMPEN, A.<br />

PLUKIS, A. POCH, C. PRETEL, J. QUESADA, T. RAUSCHER, R. REIFARTH, M. ROSETTI, C. RUBBIA, G.<br />

137<br />

Progress Report 2006


B4 Publications<br />

B Fission Technology<br />

RUDOLF, P. RULLHUSEN, J. SALGADO, L. SARCHIAPONE, I. SAVVIDIS, C. STEPHAN, G. TAGLIENTE,<br />

J.L. TAIN, L. TASSAN-GOT, L. TAVORA, R. TERLIZZI, G. VANNINI, P. VAZ, A. VENTURA, D. VILLAMARIN,<br />

M.C. VINCENTE, V. VLACHOUDIS, R. VLASTOU, F. VOSS, S. WALTER, H. WENDLER, M. WIESCHER,<br />

K.WISSHAK (The n_TOF Collaboration): Astrophysical implications of the 139 La(n,γ) and 151 Sm(n,γ) cross<br />

sections measured at n_TOF<br />

9 th Inter. Symposium on Nuclei in the Cosmos (NIC-IX), CERN (Geneva), June 25-30, 2006, SISSA<br />

Proceedings of Science (http://pos.sissa.it/), PoS (NIC-IX) 138<br />

G. TAGLIENTE, U. ABBONDANNO, G. AERTS, H. ÁLVAREZ, F. ALVAREZ-VELARDE, S. ANDRIAMONJE, J.<br />

ANDRZEJEWSKI, P. ASSIMAKOPOULOS, L. AUDOUIN, G. BADUREK, P. BAUMANN, F. BEČVÁŘ, E.<br />

BERTHOUMIEUX, F. CALVIÑO, D. CANO-OTT, R. CAPOTE, A. CARRILLO DE ALBORNOZ, P. CENNINI, V.<br />

CHEPEL, E. CHIAVERI, N. COLONNA, G. CORTES, A. COUTURE, J. COX, M. DAHLFORS, S. DAVID, I.<br />

DILLMANN, R. DOLFINI, C. DOMINGO-PARDO, W. DRIDI, I. DURAN, C. ELEFTHERIADIS, M. EMBID-<br />

SEGURA, L. FERRANT, A. FERRARI, R. FERREIRA-MARQUES, L. FITZPATRICK, H. FRAIS-KOELBL, K.<br />

FUJII, W. FURMAN, C. GUERRERO, I. GONCALVES, R. GALLINO, E. GONZALEZ-ROMERO, A.<br />

GOVERDOVSKI, F. GRAMEGNA, E. GRIESMAYER, F. GUNSING, B. HAAS, R. HAIGHT, M. HEIL, A.<br />

HERRERA-MARTINEZ, M. IGASHIRA, S. ISAEV, E. JERICHA, Y. KADI, F. KÄPPELER, D. KARAMANIS, D.<br />

KARADIMOS, M. KERVENO, V. KETLEROV, P. KOEHLER, V. KONOVALOV, E. KOSSIONIDES, M. KRTIČKA,<br />

C. LAMBOUDIS, H. LEEB, A. LINDOTE, I. LOPES, M. LOZANO, S. LUKIC, J. MARGANIEC, L. MARQUES,<br />

S. MARRONE, C. MASSIMI, P. MASTINU, A.MENGONI, P.M. MILAZZO, C. MOREAU, M. MOSCONI, F.<br />

NEVES, H. OBERHUMMER, S. O'BRIEN, M. OSHIMA, J. PANCIN, C. PAPACHRISTODOULOU, C.<br />

PAPADOPOULOS, C. PARADELA, N. PATRONIS, A. PAVLIK, P. PAVLOPOULOS, L. PERROT, R. PLAG, A.<br />

PLOMPEN, A. PLUKIS,A. POCH, C. PRETEL, J. QUESADA, T. RAUSCHER, R. REIFARTH, M. ROSETTI, C.<br />

RUBBIA, G. RUDOLF, P. RULLHUSEN, J. SALGADO, L. SARCHIAPONE, I. SAVVIDIS, C. STEPHAN, J.L.<br />

TAIN, L. TASSAN-GOT, L. TAVORA, R. TERLIZZI, G. VANNINI, P. VAZ, A. VENTURA, D. VILLAMARIN, M.C.<br />

VINCENTE, V. VLACHOUDIS, R. VLASTOU, F. VOSS, S. WALTER, H. WENDLER, M. WIESCHER,<br />

K.WISSHAK (The n_TOF Collaboration): Measurement of the 90,91,92,94,96 Zr neutron capture cross sections<br />

at n_TOF<br />

9 th Inter. Symposium on Nuclei in the Cosmos (NIC-IX), CERN (Geneva), June 25-30, 2006, SISSA<br />

Proceedings of Science (http://pos.sissa.it/), PoS (NIC-IX) 227<br />

C. GUERRERO R. CAPOTE, A. MENGONI et al. (The n_TOF Collaboration): Measurement at n_TOF of the<br />

237 Np(n, γ) and 240 Pu(n,γ) cross sections for the transmutation of nuclear waste<br />

ANS Topical Meeting on Reactor Physics (PHYSOR-2006), Vancouver (Canada), September 10-14, 2006<br />

W. DRIDI ET AL. (The n_TOF Collaboration): Measurement of the neutron capture cross section of 234U in<br />

n_TOF at CERN<br />

ANS Topical Meeting on Reactor Physics (PHYSOR-2006), Vancouver (Canada), September 10-14, 2006<br />

F. GUNSING et al. (The n_TOF Collaboration): Measurement of the neutron capture cross section of 236 U<br />

ANS Topical Meeting on Reactor Physics (PHYSOR-2006), Vancouver (Canada), September 10-14, 2006<br />

A. ANDRIGHETTO, C. ANTONUCCI, M. BARBUI, S. CARTURAN, F. CERVELLERA, S. CEVOLANI, M.<br />

CINAUSERO, P. COLOMBO, A. DAINELLI, P. DI BERNARDO, F. GRAMEGNA, G. MAGGIONI, G.<br />

MENEGHETTI, C. PETROVICH, L. PIGA, G. PRETE, V. RIZZI, M. TONEZZER, D. ZAFIROPOULOS, P.<br />

ZANONATO: The SPES direct UCx target<br />

7 th Inter. Conference on Radioactive Nuclear Beams (RNB-7), Cortina d’Ampezzo (Italy), July 3-7, 2006<br />

A. ANDRIGHETTO, C. ANTONUCCI, M. BARBUI, S. CARTURAN, F. CERVELLERA, S. CEVOLANI, M.<br />

CINAUSERO, P. COLOMBO, A. DAINELLI, P. DI BERNARDO, F. GRAMEGNA, G. MAGGIONI, G.<br />

MENEGHETTI, C. PETROVICH, L. PIGA, G. PRETE, V. RIZZI, M. TONEZZER, D. ZAFIROPOULOS, P.<br />

ZANONATO: The SPES direct UCx target<br />

IX Inter. Conference on Nucleus-Nucleus Collisions, Rio de Janeiro (Brazil), August 28-September 1, 2006<br />

Progress Report 2006<br />

138


F. GRAMEGNA, A. ANDRIGHETTO, C. ANTONUCCI, M. BARBUI, L. BIASETTO, G. BISOFFI, S. CARTURAN, L.<br />

CELONA, F. CERVELLERA, S. CEVOLANI, F. CHINES, M. CINAUSERO, P. COLOMBO, M. COMUNIAN, G.<br />

CUTTONE, A. DAINELLI, P. DI BERNARDO, E. FAGOTTI, M. GIACCHINI, M. LOLLO, G. MAGGIONI, M.<br />

MANZOLATO, G. MENEGHETTI, G.E. MESSINA, A. PALMIERI, C. PETROVICH, A. PISENT, L. PIGA, G. PRETE,<br />

M. TONEZZER, M. RE, V. RIZZI, D. RIZZO, D. ZAFIROPOULOS, P. ZANONATO: The SPES direct target project at<br />

LNL<br />

Zakopane Conference on Nuclear Physics, Zakopane (Poland), September 4-10, 2006<br />

Medical, Energetic and Environmental Applications<br />

K. W. BURN, L. CASALINI, S. MARTINI, D. MONDINI, E. NAVA, G. ROSI, R. TINTI: Final design and construction<br />

issues of the TAPIRO epithermal column<br />

12 th Inter. Congress on Neutron Capture Therapy (ISNCT-12), Takamatsu (Japan), October 9-13, 2006, ISNCT<br />

Proceedings, p. 564 (2006)<br />

G. GAMBARINI, S. AGOSTEO, S. ALTIERI, S. BORTOLUSSI, M. CARRARA, S. GAY, M. MARIANI, C. PETROVICH,<br />

G. ROSI, E. VANOSSI: Dose imaging with gel dosimeters in phantoms exposed in reactor thermal columns<br />

designed for BNCT<br />

12 th Inter. Congress on Neutron Capture Therapy (ISNCT-12), Takamatsu (Japan), October 9-13, 2006, ISNCT<br />

Proceedings, p. 417 (2006)<br />

P. FERRARI, G. GUALDRINI, E. NAVA, K. W. BURN: Preliminary evaluations of the undesirable patient dose from<br />

a BNCT treatment at the <strong>ENEA</strong>-TAPIRO reactor<br />

10 th Symposium on Neutron Dosimetry, Uppsala (Sweden), June 12-16, 2006<br />

G. GAMBARINI, S. AGOSTEO, S. ALTIERI, S. BORTOLUSSI, M. CARRARA, S. GAY, E. NAVA, C. PETROVICH, G.<br />

ROSI, M. VALENTE: Dose distributions in phantoms irradiated in thermal columns of two different nuclear reactors<br />

10 th Symposium on Neutron Dosimetry, Uppsala (Sweden), June 12-16, 2006<br />

J. ESPOSITO, G. ROSI, S. AGOSTEO: The new hybrid thermal neutron facility at TAPIRO reactor for BNCT<br />

radiobiological experiments<br />

10 th Symposium on Neutron Dosimetry, Uppsala (Sweden), June 12-16, 2006<br />

K.W. BURN, L. CASALINI, E. NAVA, G. ROSI, R. TINTI: The epithermal column for BNCT at the TAPIRO reactor<br />

Workshop on Innovative Treatment Concepts for Liver Metastases, University Hospital Essen (Germany),<br />

December 7-9, 2006<br />

139<br />

Progress Report 2006


C1 Radioactive Waste Management and<br />

Advanced Nuclear Fuel Cycle Technologies<br />

C Nuclear Protection<br />

In 2006 <strong>ENEA</strong>’s Department of Nuclear Fusion and Fission, and Related Technologies (Dipartimento <strong>Fusione</strong>,<br />

Tecnologie e Presidio Nucleare [FPN]) acted according to national policy and to the role assigned to <strong>ENEA</strong><br />

FPN by Law 257/2003 with regard to radioactive waste management and advanced nuclear fuel cycle<br />

technologies.<br />

C1.2 Entrustment of <strong>ENEA</strong>’s Fuel Cycle Facilities and<br />

Personnel to Sogin<br />

The management of <strong>ENEA</strong>’s fuel cycle facilities (EUREX Saluggia - spent fuel reprocessing; ITREC<br />

Trisaia - spent fuel reprocessing; IPU Casaccia - fuel element fabrication; OPEC Casaccia - postirradiation<br />

analysis) has been assigned to the Società Gestione Impianti Nucleari SpA (Sogin)<br />

through the “Entrustment of Management Act” and integrating annexes, signed by the <strong>ENEA</strong><br />

Director General and the Sogin Executive Manager on 23 December 2005. <strong>ENEA</strong> has seconded its<br />

expert personnel to Sogin to enable full operability of the facilities and to ensure that all the technical<br />

prescriptions be achieved and that the activities concerning site decommissioning be fully exploited.<br />

C1.3 Characterisation, Treatment and Conditioning of<br />

Nuclear Materials and Radioactive Waste<br />

The Laboratory for the Characterisation of Nuclear Materials at <strong>ENEA</strong> Casaccia, in collaboration with<br />

the universities, carries out nuclear and radioactive material analyses, R&D on reprocessing fuel<br />

used in new-generation reactors (e.g., PYREL project, see sect. B1.1) and is the reference lab for<br />

characterisation of conditioned/non-conditioned radioactive waste. Above all the laboratory has to<br />

guarantee Italy the functions of radioactive-material characterisation and process qualification. The<br />

laboratory manages four operative areas: two classified areas (C-43 Radiochemical Laboratory and<br />

C-25 Technological Hall - Zone A) and two cold areas (CETRA Laboratory and C-25 Technological<br />

Hall - Zone B).<br />

The C-43 Radiochemical Laboratory is authorised through a Category A decree to carry out nondestructive<br />

measurements of radioactive waste and materials by means of gamma spectrometry<br />

systems. Table C1.I briefly describes the available techniques.<br />

The first two techniques, implemented on the SEA radioactive-waste gamma analyser<br />

Progress Report 2006<br />

140


Table C1.I - Techniques used for nondestructive measurements of radioactive wastes & materials<br />

Measurement technique Field of application Input Output<br />

Emission & transmission Characterisation of 220–and - Volume of the drum Total Activity and relative<br />

axial scan segmented 400–litre drums containing - Collimation axial distribution for each<br />

gamma scanner (SGS) gamma emitter radionuclides - Radionuclide library radionuclide identified<br />

- Quantitative analysis reports<br />

Software: Segment 2.1<br />

given by the spectroscopy<br />

software Genie 2k<br />

Angular scanning (AS) Characterisation of 220–and - Detection efficiency curve Number, position and<br />

400–litre drums containing for point source activity of each identified<br />

Software: Ascanio 1.1 gamma emitter radionuclides - Linear attenuation factor radionuclide<br />

- Radionuclide library<br />

- Quantitative analysis reports<br />

given by the spectroscopy<br />

software Genie 2k<br />

Low–resolution Characterisation of 220 and - Detection efficiency curve - Spatial attenuation<br />

emisssion & transmission 400 litre drums containing for point source factor distribution<br />

tomography ((ECT/TCT) gamma emitter radionuclides - Linear attenuation factor - Spatial activity distribu-<br />

- Radionuclide library tion for each<br />

Software Plinius 1.1 - Quantitative analysis reports radionuclide identified<br />

given by the spectroscopy - Total activity for each<br />

software Genie 2k<br />

radionuclide identified<br />

In-situ object counting Characterisation of various - Accurate description of - Total activity for each<br />

system (ISOCS) objects containing gamma measurement configura- radionuclide identified<br />

emitter radionuclides<br />

tion<br />

Software: Genie2k<br />

- Radionuclide library<br />

ISOXSW<br />

(SRWGA, fig. C1.1), have the same field of application but are characterised by different levels of<br />

accuracy according to activity and density distribution of the matrix, while for the electrical capacitance<br />

tomography/transmission computer tomography (ECT/TCT) techniques these characteristics have no<br />

influence on the reliability of results. The weakness of ECT/TCT is only the measuring time (typically<br />

18 h/drum). It is also worth noting that when the segmented gamma scanner (SGS) is used, variations in<br />

matrix density and in the activity distribution inside the matrix could lead to overestimation or<br />

underestimation of the real activity up to a factor of 10.<br />

The ISOCS (fig. C1.2) is used in a wide variety of measurement applications. The most important<br />

characteristic of the ISOCS is its capability to obtain radionuclide activity by applying pre-defined geometry<br />

templates in the analysis software: defining the<br />

template, the user obtains an evaluation of the<br />

overall efficiency curve without needing<br />

experimental calibration. However, the<br />

measurement configuration has to be defined and<br />

reproduced by the user with good accuracy, even<br />

though this is not always allowed because of<br />

practical problems.<br />

In 2006 experimental measurement campaigns<br />

were carried out to validate the ISOCS and assess<br />

Fig. C1.1 - SRWGA gamma system<br />

141<br />

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C1 Radioactive Waste Management<br />

Fig. C1.2 - ISOCS detector<br />

C Nuclear Protection<br />

its performance. Measurements were performed on several<br />

220-litre drums (with differing matrix density and distribution)<br />

equipped with various configurations of certified gammaemitting<br />

sources placed at different positions. The aim was to<br />

illustrate the problems that can compromise the application<br />

of this measurement technique and to simulate the following<br />

real situations:<br />

• characterisation of 220-litre raw waste drums and<br />

conditioned waste drums;<br />

• localisation and quantification of buried and covered<br />

activity;<br />

• quantification of activity in sealed containers.<br />

The results obtained have clearly defined the field of application of ISOCS (for small samples or, with<br />

appropriate measurements and analysis procedures, for large samples and buried activity) and will<br />

be the basis for future research activities and for setting up the technical procedure to be accredited<br />

according to ISO-17025 in autumn 2007. The same activity was foreseen for 400-litre drums, but it<br />

was put forward to 2007 because of mechanical problems with the SRWGA.<br />

The CETRA Laboratory is specialised in the formulation and characterisation of matrices for<br />

conditioning toxic and/or radioactive wastes. In accordance with the Technical Guide 26 of the<br />

Italian Agency for Environmental Protection and Technical Services (APAT) for the management of<br />

radioactive waste, the laboratory studies, qualifies and sets up processes for treating and<br />

conditioning radioactive wastes and performs the chemical and physical-mechanical<br />

characterisation of the conditioned products, obtained via the employment of chemical elements<br />

simulating real waste.<br />

Fig. C1.3 - Tensile strength tester<br />

C1.4 Radioprotection and Human Health<br />

The qualification of the conditioning<br />

processes consists of a series of activities<br />

aimed at demonstrating that the matrix<br />

resulting from the conditioning process<br />

complies with the minimum requirements for<br />

interim storage, transport and clearance of<br />

waste. The major tests performed are tensile<br />

strength (fig. C1.3); cyclic temperature<br />

gradient resistance; radiation damage<br />

resistance; fire resistance; leaching test; free<br />

liquid absence; bio-degradation resistance<br />

and immersion resistance. Some tests (biodegradation<br />

resistance, leaching test and<br />

radiation damage resistance) are performed<br />

in cooperation with other <strong>ENEA</strong> laboratories.<br />

Methodological proposal for the evaluation of a physiological comfort index in<br />

indoor environments<br />

Carried out in the framework of a research activity supported by the National Institute of<br />

Occupational Safety, Health and Prevention (ISPESL), the aim is to propose a physiological comfort<br />

Progress Report 2006<br />

142


and Advanced Nuclear Fuel Cycle Technologies<br />

index for workers wearing personal protective equipment. Many attempts have been made to combine<br />

environmental with physiological parameters in order to develop a single index. Currently there are many<br />

indices, but none of them is widely accepted. The main reason lies in the great complexity and plurality of<br />

interactions among the main factors to take into account when defining the index. A survey on<br />

physiological comfort indices showed that the Physiological Strain Index (PSI) is the most appreciated as<br />

individual reactions to it are only based on core temperature and heart rate. Moreover, the PSI can assess<br />

in real time physiological responses both to heat and heat strain between any combination of climate,<br />

clothing and work rate. The PSI does not consider sweat rate because of the intrinsic difficulty in<br />

performing an on-line measurement: nevertheless this term should be taken into account, especially in the<br />

case of short and repeated operations.<br />

The work, carried out with La Sapienza University of Rome, proposes the use of two physiological comfort<br />

indices: the first concerns long-lasting operations; the second, short and repeated operations. In the first<br />

case the suggested index is like the PSI index; it is possible to take into account the effects of cooling<br />

devices operating with personal protective equipment by reducing the index value. In the second case<br />

another term linked to sweat rate can be introduced. To calculate the value of coefficients in the new<br />

physiological comfort index, it is necessary to carry out a measurement campaign on a sufficiently wide<br />

population. These measurements should lead to a quantitative evaluation of the importance of the term<br />

considering the presence of cooling systems in personal protective equipment.<br />

LCA of strippable coating and the principal competing technology used for nuclear<br />

decontamination<br />

Life cycle assessment (LCA) is a systematic way to evaluate the environmental impact of products or<br />

activities throughout their entire life cycle by following a “cradle to grave” approach. This approach implies<br />

the identification and quantification of emissions, materials and energy consumption, which affect the<br />

environment at all stages of the entire life cycle of the product. The application of strippable coatings is an<br />

innovative technology for decontamination of nuclear plants and for any decontamination project where the<br />

purpose is to remove surface contamination (such as polychlorobiphenyls (PCBs), asbestos particles, etc).<br />

It effectively reduces hazardous residuals, at low cost. An adhesive plastic coating is applied on the<br />

contaminated surface. The strippable coating is allowed to cure for up to 24 h, after which it can be easily<br />

peeled. The coating traps the contaminants in the polymer matrix. Strippable coatings are non-toxic and<br />

do not contain volatile compounds or heavy metals. Since the coating constitutes solid waste, disposal is<br />

easier than treating contaminated liquid wastes produced by the baseline technology.<br />

The competing baseline technology is the steam vacuum cleaning technology based on superheated<br />

pressurised water, used to remove contaminants from floors and walls. The LCA was carried out to<br />

compare the strippable coating with the steam vacuum technology. The functional unit of the study is<br />

represented by a surface of 1 m 2 to be decontaminated. The results of LCA achieved using Sima<br />

Pro 5.0 ® software confirmed the good environmental performance of strippable coatings. The storage<br />

phase is the phase showing the most important differences between the two technologies. For this reason<br />

this phase was studied in detail, even from the economic point of view. A simplified economic analysis of<br />

only the storage phase showed higher costs for the steam vacuum technology. In a further development<br />

of the work, the cost of all the phases could be examined in order to confirm or not the best behaviour of<br />

the strippable coating, also from the economic point of view.<br />

C1.5 Integrated Service for Non-Energy Radwaste<br />

Radioactive waste is generated in a broad range of activities involving the use of radioactive material in<br />

different conventional fields, such as medicine, industry, agriculture, research and education. In general the<br />

waste generated in these fields is often limited in volume and activity; however it has to be managed like<br />

the other radwaste from nuclear power plants.<br />

143<br />

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C1 Radioactive Waste Management<br />

C Nuclear Protection<br />

Italy has no radwaste national repository, so Government has entrusted <strong>ENEA</strong> with the management<br />

of radioactive waste coming from small producers (collection, transport, characterisation, treatment,<br />

conditioning, interim storage, or release for waste with short life radio-nuclides, after their<br />

radioactivity decay). <strong>ENEA</strong> has organised a special technical-operative service, called “Integrated<br />

Service”, and is responsible for the guidance, supervision and control of the whole cycle of waste<br />

management. <strong>ENEA</strong> has entrusted NUCLECO SpA with the operative and commercial tasks, and<br />

offered the company access to specific facilities and infrastructures, located at the Casaccia<br />

Research Centre. The two parties drew up a special agreement laying out mutual duties and<br />

responsibilities.<br />

Integrated Service has also collected thirty disused sealed radioactive sources with Cs-137 and<br />

Co–60 and about seventy grams of Ra-226 no longer used in medical therapy. Except for this last<br />

type of waste, <strong>ENEA</strong> becomes the owner of all the radwaste collected and deals with the final<br />

release, leaving the waste producers free of any juridical responsibility. Integrated Service is available<br />

to private companies operating in this sector. The companies supply collecting services and<br />

temporary storage. <strong>ENEA</strong> provides qualification for the companies and gives them specific<br />

technical-operational procedures.<br />

C1.6 Transport of Nuclear Material<br />

Packaging for transport of radioactive material<br />

The Laboratory for Characterisation of Nuclear Materials is a permanent member of the European<br />

Network of Testing Facilities for the Quality Checking of Radioactive Waste Packages. (EN-TRAP:<br />

created in 1992 on the initiative of the European Commission.) The objectives are to promote<br />

collaboration on the development, application and standardisation of quality checking for waste<br />

packages. The network involves the reference laboratories of the European Union member states<br />

that verify the regulatory issues on waste packages. In this framework the laboratory participates in<br />

steering committee meetings and in technical-scientific activities regarding the characterisation of<br />

the radioactive wastes, promoted by the working groups. In 2006 one meeting of the steering<br />

committee took place in April at Winfrith (UK) and one meeting of working group D (Quality<br />

Checking of ILW/HLW), in September in Brussels.<br />

As <strong>ENEA</strong>-NUCLECO (see sect. C1.5) has to store, transport and dispose of radio needles and some<br />

large radioactive sources, the following activities have been carried out:<br />

• Preparation of a management system for quality assurance. This is fundamental for the approval<br />

process of a package model by the competent authority (APAT) and the emission of the<br />

corresponding certificate.<br />

• Design of a new dual-purpose (storage and transport) package using the scale factors already<br />

developed in the past for the CF66. The first instance will contain only the radium needles. The<br />

objective is to improve warehouse safety. Once the certificate of approval type B(U) is released<br />

by APAT, the transport modality will be studied, with the inclusion of cobalt and caesium sources.<br />

• Obtaining authorisation to dismount the irradiation heads and their packing according to the IAEA<br />

radioactive sources catalogue.<br />

• Once the management system for quality assurance is set up, application will be made to renew<br />

the certificate of approval for CF6 and CF66 packaging.<br />

• Qualification of industrial packaging (IP) of type A for transport of radioactive material.<br />

• Contributions to the updating and revision of national and international transport regulations.<br />

• Participation in the IAEA group for “Regulations for the Safe Transport of Radioactive Material”<br />

(Transport Safety Standards Committee).<br />

Progress Report 2006<br />

144


and Advanced Nuclear Fuel Cycle Technologies<br />

C1.7 Disposal of Radioactive Waste<br />

Artificial barriers for disposal units<br />

The research regarded mainly cementitious materials and was carried out in collaboration with the<br />

Departments of Structural Engineering and of Chemistry-Physics of Milan Polytechnic, EN.CO. Srl a wellknown<br />

laboratory working with concrete and the Experimental Testing Laboratory of CESI-ISMES SpA.<br />

The work was divided into three steps: identifying the optimal characteristics for structural concrete and<br />

grout; investigating their properties through artificial aging tests; testing their efficiency in module<br />

prototypes.<br />

A systematic study was performed to establish a reference mix-design, taking into account all possible<br />

environmental attacks in Italy for a period of 300 years. A series of tests simulating the chemical and<br />

physical attacks forecasted was then carried out on several specimens compounded with aggregates from<br />

four different Italian regions. In addition a suitable concrete mix-design was obtained through the<br />

ANSI/ANS 16.1.1986 leakage tests, carried out on a 300x300-mm-wide concrete slab. Four full-scale<br />

module prototypes were then built, within the framework of the project on designing a final repository for<br />

low-activity radioactive waste, from the same concrete mix and submitted to a waterproofing test at the<br />

Ismes Laboratory. The main object of the study was leaching, i.e., the selective transport of particles<br />

occurring in a material once water seepage is established, which can be activated by weathering of the<br />

material in the longer term. One prototype was also submitted to a seismic test of 1 g.<br />

All the trials and tests confirmed the adequacy of the design and the materials chosen, and analysis of the<br />

achievements indicated ways to improve the module performance, e.g., by using fibre-reinforced concrete<br />

with new-generation additives and considering minor strength requirements under dynamics stresses.<br />

The theoretical studies were completed by using a Monte Carlo simulation method based on the theory of<br />

branching stochastic processes. Also addressed was the issue of radionuclide transport through the<br />

artificial porous matrices constituting the engineered barriers: the complexity of the phenomena involved,<br />

augmented by the heterogeneity and stochasticity of the media in which transport occurs, renders classical<br />

analytical-numerical approaches scarcely adequate for a realistic representation of the system of interest.<br />

This approach, applied in the artificial porous matrices hosting the waste (near field), can certainly be<br />

usefully extended to study the phenomena of advection and dispersion of radionuclides in the natural rock<br />

matrix of the host geosphere (far field).<br />

145<br />

Progress Report 2006


D1 Advances in the IGNITOR Programme<br />

D Miscellaneous<br />

The IGNITOR project has continued to progress both in the machine engineering design and related<br />

auxiliary systems and in the definition of the physics programme. The validity of the objectives of the<br />

IGNITOR programme and of its design solutions were reaffirmed by PH. Rebut at the latest EPS<br />

meeting in Rome: i) in order to prove the scientific feasibility of relevant fusion reactors, burning<br />

plasmas with Q > 50 should be produced and studied; ii) copper magnets are the most convenient<br />

solution for machines capable of reaching this objective; iii) experiments that do not include a<br />

divertor are the most efficient at producing the highest plasma currents with the best confinement<br />

parameters.<br />

While ignition scenarios in IGNITOR have been extensively analysed in the past, plasma regimes and<br />

the physics objectives that can be achieved when operating the machine at lower parameters have<br />

been further explored. In particular, at B T ≅9 T, and I p ≅7 MA in the “extended limiter” configuration or<br />

I p ≅6 MA in the double null configuration, in D-T plasmas, simulations performed with the JETTO<br />

code show that the ideal ignition temperature can be attained. This is the point where the energy<br />

loss by Bremsstrahlung emission is compensated for by α-particle heating, and the density can be<br />

raised further without encountering a radiation barrier. These regimes require a certain amount of ion<br />

cyclotron resonance heating (ICRH) (5-8 MW at ~90 MHz). A parametric study of the power<br />

deposition profiles as a function of minority concentration, minority species, and frequency range<br />

was carried out by solving the 2D full wave equation, which describes the plasma-wave interaction,<br />

in toroidal geometry.<br />

IGNITOR can operate with a double-null configuration at B T ≅13 T, and I p ≅9 MA. On the basis of<br />

recent scalings, the power threshold to access the H-mode regime is considerably lower than<br />

previously estimated. The expected plasma parameters were evaluated by using a 0-D model,<br />

which showed the existence of a relatively broad region of operation corresponding to Q ≅ 10, even<br />

in the pessimistic case of rather flat density profiles. With more peaked profiles (e.g., n 0 / ≅ 1.5),<br />

of the type being observed in some JET experimental data, the attainable plasma parameters are<br />

found to improve considerably and values of Q much larger than 10 can be attained. The<br />

construction of the four-barrel two-stage IGNITOR<br />

pellet injector, in collaboration with the Oak Ridge<br />

National Laboratory (ORNL), is nearly completed<br />

(fig. D1). The development of new, fast pulse<br />

shaping valves will make it possible to reach pellet<br />

velocities of 4 km/s. The propulsion system, built in<br />

Italy, will be shipped to ORNL for final integration<br />

with the ORNL cryogenic and control systems, and<br />

pellet performance characterisation. The possible<br />

application of the injector to JET has been<br />

explored, but other large existing devices are also<br />

being considered.<br />

The design of the full set of electromagnetic<br />

diagnostics for the IGNITOR experiment and their<br />

integration with the plasma chamber has been<br />

completed. Because the estimated neutron flux at<br />

the first wall during high-performance discharges<br />

is expected to cause a sensible, although<br />

Fig. D1 – a) The <strong>ENEA</strong> Frascati sub-system of the Ignitor pellet<br />

injector during testing at Criotec Impianti in Chivasso (Turin, Italy). b)<br />

In-flight picture of a 3-mm D2 pellet, travelling at about 1.2 km/s<br />

Progress Report 2006<br />

146


Fig. D2 – a) Lateral and b) top views of the IGNITOR machine obtained from<br />

integration of the CATIA CAD drawing of the detailed design of all the<br />

components of the machine itself<br />

a)<br />

reversible, degradation of the inorganic insulator surrounding the<br />

conductors, an R&D program aimed at selecting insulator<br />

materials and fabrication procedures has been established. Two<br />

prototype coils made of pre-insulated nickel wire immersed in a<br />

magnesium oxide weakly bonded powder were manufactured in<br />

collaboration with the University of Lecce (Italy) and SALENTEC.<br />

Vacuum tightness is provided by sintered alumina cases or by<br />

oxide ceramic composite wrapping layers.<br />

An alternative diagnostic method for plasma position control has<br />

been proposed: using a multilayer mirror as the dispersing<br />

element for the soft x-ray radiation emitted from the plasma outer<br />

region and a gas electron multiplier detector would allow the<br />

radiation from the lower or upper part regions to be diffracted to<br />

the 2D detector placed outside one of the machine horizontal<br />

ports, not in direct view of the plasma, to minimise the<br />

background radiation noise. This system should measure the<br />

plasma position and detect any movements with sufficient spatial<br />

and time resolution to be used for real-time control of the vertical<br />

position.<br />

b)<br />

The detailed design of the machine was completed during 2006,<br />

taking as reference the maximum performance scenario<br />

(11 MA/13 T/extended limiter). This design will be checked,<br />

referring to the double-null configuration at B T ≅13 T, and<br />

I p ≅9 MA.<br />

The machine integration was also completed during the reporting<br />

year, starting from the CATIA CAD of each component of the<br />

machine. As far as known, this is the first time that a detailed CAD-based integration has been performed<br />

for such a complex apparatus. Figure D2 shows an example of the integration results.<br />

D2 Ultra-Pure Hydrogen Production<br />

Project (FIRB RBAU01K4HJ) funded by the Italian Ministry of Education, University and<br />

Research. Long-term tests (more than one year) of thin-wall Pd-Ag permeator tubes produced at <strong>ENEA</strong><br />

Frascati laboratories were carried out and the capability to produce ultra-pure hydrogen as well as the<br />

durability of the permeators were demonstrated [D1].<br />

A membrane process for producing hydrogen from hydrocarbon and alcohol reforming was developed<br />

[D2–D4] and a Pd-Ag multi-tube membrane reactor capable of producing 6 L/min of pure hydrogen was<br />

[D1] S. Tosti et al., Long-term tests of Pd–Ag thin wall permeator tube, J. Membrane Sci. 284, 393–397 (2006)<br />

[D2] S. Tosti et al., Procedimento a membrana per la produzione di idrogeno da reforming di composti organici, in particolare idrocarburi o<br />

alcoli, Domanda di brevetto per invenzione industriale n. RM2006A000102 del 01.03.2006<br />

[D3] S. Tosti et al., Design and characterization of membrane reactors for producing hydrogen via ethanol reforming, <strong>ENEA</strong> Internal Report<br />

FUS TN BB-R015 (2006)<br />

[D4] S. Tosti et al., Pd membrane reactor design, Desalination 200, 676-678 (2006)<br />

References<br />

147<br />

Progress Report 2006


Miscellaneous<br />

Fig. D3 – The multi-tube membrane reactor<br />

Fig. D4 – Particulars of<br />

the flange supporting<br />

the Pd–Ag permeator<br />

tubes<br />

built (figs. D3 and D4). A lot of<br />

experimental work concerning the<br />

methanol and ethanol steam reforming<br />

reactions in Pd-Ag membrane reactors<br />

was performed [D5–D7] and it was<br />

demonstrated that the membrane is able<br />

to promote the reaction conversion<br />

beyond the thermodynamic limit. In<br />

particular, at 450°C a high hydrogen yield<br />

was attained via the ethanol steam<br />

reforming on a Ru–based catalyst.<br />

Figure D5 reports the hydrogen yield<br />

measured in the shell side of the Pd–Ag<br />

membrane reactor.<br />

Shell side<br />

hydrogen yield (%)<br />

100<br />

80<br />

60<br />

40<br />

200k Pa<br />

150k Pa<br />

20<br />

0<br />

0 5 10 15 20 25<br />

Feed flow rate (g h -1 )<br />

Fig. D5 – Shell-side hydrogen percent yield at 450°C and<br />

feed molar ratio H 2 O/EtOH=13<br />

D3 Non-ITER Activities<br />

Cryogenic testing of superconductive current leads for CERN. Since September 2004 <strong>ENEA</strong><br />

has been responsible for the cryogenic tests of the complete series of 6000 A and 13000 A Large<br />

Hadron Collider (LHC) HTS current leads, consisting of 333 units.The whole job also included, as a<br />

first step, testing of the pre-series lead production, manufactured and assembled at CERN.<br />

The main campaign of tests involving the current leads produced by the BINP laboratory, Russian<br />

Federation (6 kA) and by CECOM, Italy (13 kA), started in the second half of 2005, and proceeded<br />

throughout 2006, thereby meeting the tight time schedule requested by CERN.<br />

Thanks to <strong>ENEA</strong>’s dedicated measurement facility, characterised by a high-precision signal<br />

acquisition system, the results showed very good reproducibility of both the electrical and the<br />

thermo-hydraulic performances of the leads in LHC-relevant operating conditions and all the tested<br />

samples fully met the requirements of the CERN technical specifications.<br />

The measurement campaign is foreseen to be completed within the first months of 2007.<br />

Progress Report 2006<br />

148


D4 Condensed Matter Nuclear Science<br />

Material science and calorimetry. Cold fusion matter, now more properly renamed “condensed matter<br />

nuclear science”, has been debated over for the last two decades [D8]. Prestigious institutions have been<br />

working in this field and some have cooperated successfully. It was discovered [D9, D10] that the<br />

phenomenon of excess power production was a threshold effect occurring only if the average deuterium<br />

concentration in the palladium lattice was not less than 0.9 (atomic fraction). Studies performed at <strong>ENEA</strong><br />

Frascati highlighted the fact that the high loading of deuterium in the lattice was not reproducible when<br />

using commercial palladium. Hence, a wide material-science study was carried out to produce a metal with<br />

a proper metallurgical structure, capable of giving a very high deuterium concentration during<br />

electrochemical loading.<br />

Under contract agreements <strong>ENEA</strong> delivered cathodes prepared with such a particular palladium to SRI<br />

International (California USA) and Energetics Ltd. (US company with a research centre in Israel). A<br />

reasonable level of transferred reproducibility was achieved by the three groups and this was one of the<br />

reasons for promoting a two-phase research project with government funding in the USA to revisit the<br />

“cold fusion effect”. <strong>ENEA</strong> was involved in the programme as <strong>ENEA</strong> cathodes were selected for the<br />

research. During the first phase SRI International was charged with replicating the results obtained with<br />

<strong>ENEA</strong>’s cathodes and with the calorimeters used by Energetics Ltd. Phase 1 was concluded at the<br />

beginning of 2007 with results well above the objectives defined by the US Government referees, and<br />

continuation of the project towards Phase 2 was approved. In the second phase, the US Naval Research<br />

Laboratory is also involved in replicating the experiments.<br />

The Italian Ministry of Economic Development (MSE) supported a two-year project (Produzione di Eccesso<br />

di Potenza in Metalli Deuterati) to improve the material science study and to gain an enhanced signal/noise<br />

ratio. Material science studies have been extended to<br />

surface physics aspects and to interphase physics, with the<br />

involvement of the University of Rome La Sapienza. The<br />

Italian project began in January 2006 and overlapped Phase<br />

1, so the two projects have been developed in parallel.<br />

During this period both <strong>ENEA</strong> and SRI International gained a<br />

reproducibility not less than 60% with a signal/noise ratio well<br />

above the measurement uncertainty. Figure D6 shows the<br />

<strong>ENEA</strong> flow calorimeters; figure D7 the excess power<br />

observed during the experimental campaign performed at<br />

<strong>ENEA</strong> (experiment L17) and figure D8 the increase in the<br />

electrolyte temperature associated with the excess.<br />

The power gain was 500% with an input and an output<br />

power of 0.1 W and 0.6 W, respectively (measurement<br />

Fig. D6 – Calorimeter room at <strong>ENEA</strong> Frascati<br />

[D5] F. Gallucci et al., Methanol and ethanol steam reforming in membrane reactors: An experimental study, Int. J. Hydrogen Energy (2006),<br />

doi: 10.1016/j.ijhydene.2006.11.019<br />

[D6] A. Basile et al., Co-current and counter-current modes for methanol steam reforming membrane reactor: Experimental study, Catalysis<br />

Today 118, 237–245 (2006)<br />

[D7] A. Basile et al., The pressure effect on ethanol steam reforming in membrane reactor: experimental study, Desalination 200, 671–672<br />

(2006)<br />

[D8] M. Fleishmann and S. Pons, J. Electroanal. Chem. 261, 301 (1989).<br />

[D9] M. McKubre et al., Excess power observation in electrochemical studies of the D/Pd system; the influence of loading, Proc. 3 rd Inter.<br />

Conference on Cold Fusion (Nagoya 1992) p. 5<br />

[D10] K. Kunimatsu et al., Deuterium loading ratio and excess heat generation during electrolysis of heavy water by a palladium cathode in a<br />

closed cell using a partially immersed fuel cell anode, Proc. 3 rd Inter. Conference on Cold Fusion (Nagoya 1992), p. 31<br />

References<br />

149<br />

Progress Report 2006


Miscellaneous<br />

0.6<br />

Fig. D7 – Input and output (upper curve) power evolution in<br />

the experiment L17<br />

W out<br />

W in<br />

Power (W)<br />

0.4<br />

0.2<br />

uncertainty ±20 mW). Of the many experiments<br />

performed with hydrogen, not one has produced<br />

excess power.<br />

Temperature (°C)<br />

0<br />

200000 240000 280000<br />

Time (s)<br />

30.0<br />

T cell<br />

29.0<br />

28.0<br />

27.0<br />

T box<br />

26.0<br />

25.0<br />

200000 240000 280000<br />

Time (s)<br />

Fig. D8 – Electrolyte temperature evolution:<br />

temperature increase is well correlated with the<br />

excess of power<br />

Figure D7 shows that during the excess the input<br />

power decreases due to the power supply<br />

operating mode (galvanostat) because the strong<br />

excess of power (up to 620 mW) caused the<br />

temperature of the electrolyte to increase<br />

(fig. D8), which was responsible for reduced<br />

electrolyte resistivity and also of the cathode<br />

interfacial impedence, so a lower voltage was<br />

required to maintain the set point current. The<br />

consequence was a reduction in input power<br />

during the burst. The conclusion was 620 mW of<br />

output with an input of 125 mW, hence an output<br />

gain of 500%.<br />

Similar results were observed with <strong>ENEA</strong>’s<br />

cathodes at SRI International. The statistics<br />

revealed that the cathode lots producing excess<br />

power at <strong>ENEA</strong> had, in general, the same<br />

behaviour at SRI. On the contrary, any lot that did<br />

not produce excess power at <strong>ENEA</strong> did not<br />

produce it at SRI International either.<br />

Despite the very high excess of power observed, the most relevant point is the energy gain<br />

associated with power gain. Energy gains up to some MJ have been observed in <strong>ENEA</strong>’s cathodes<br />

(6.25 keV per atom into the electrode). Energy gain is a crucial point because a large amount of the<br />

energy produced cannot be simply justified as a chemical effect if sharing the energy between all<br />

the atoms embedded in the electrode produces, as already reported, an energy per atom well above<br />

a few eV. A possible explanation is that there is a mechanism accumulating energy in the system at<br />

a very slow rate so that no negative power gain is detected by the calorimeter because outside the<br />

detection limits. In the case of a fast energy release, as in the Wigner effect, an apparent excess of<br />

power would be revealed by the calorimeter; however, such an energy gain would have to be of the<br />

order of a few eV/atom in order to be ascribed to a chemical effect, which is in contrast with the<br />

experimental observations.<br />

The amount of energy gain and the occurrence of the effect with deuterium and not with hydrogen<br />

point in the direction of a nuclear fusion reaction between two deuterons producing, in the lattice,<br />

4 He and heat. This is in agreement with preliminary measurements of 4 He [D11-D14], which reveal<br />

an increase in the concentration above the ambient level, consistent with the energy gain.<br />

In 2005 a very positive co-operation was started in the field of materials science with the Materials<br />

Branch of the Naval Research Institute of Washington DC. This ongoing research activity is funded<br />

by the Office of Naval Research Global (ONRG), London UK, and an important experiment has<br />

already been carried out at the Brookhaven National Laboratory, USA. X-ray diffraction was<br />

performed during electrochemical loading of cathodes prepared at <strong>ENEA</strong> in order to study the<br />

palladium hydride (deuteride) in the so far unexplored region of loading above H(D)/Pd>1. The<br />

experiment was concluded successfully by collecting more that 240 spectra.<br />

Progress Report 2006<br />

150


The support received by MSE has made it possible to extend<br />

the material science study by performing a systematic<br />

characterisation of the surface of cathodes on the basis of<br />

the atomic force microscopy (AFM) and scanning electron<br />

microscopy (SEM) analyses.<br />

Microscopic characterisation of finished electrodes<br />

before electrolysis. Microscopic characterisation of the<br />

electrodes was performed in order to correlate the<br />

characteristics of the cathodes before loading and the<br />

excess power production during electrochemical deuterium<br />

loading.<br />

Three cathodes produced from three different lots of rough<br />

materials, but with similar rolling, thermal annealing and<br />

chemical etching processes were analysed and showed<br />

different behaviour in heat production. The deuterium loading<br />

was fairly similar in all three samples and above the threshold<br />

(D/Pd>0.9). The nominal purity of the rough foils is 99.95 for<br />

L25b and L35 and 99.98 for L40.<br />

L25b<br />

100 µm EHT=20.00 kV Signal A=CZ BSD<br />

WD=9.5 mm Mag=200x<br />

L35<br />

a)<br />

b)<br />

SEM analysis. SEM analysis showed different<br />

characteristics in grain size distribution, grain boundary<br />

shape and surface morphology. Figure D9 reports a<br />

comparison of the SEM images of the three samples. Sample<br />

L40 shows an average grain size smaller than the other two<br />

samples; sample L25, the larger dimensions of the grains.<br />

Furthermore, in L40 some of the grain boundaries have a<br />

particular “crest-like” shape, while in L25b and L35 the<br />

boundaries have the more usual “valley-like“ shape. These<br />

characteristics were checked by AFM recording of the<br />

surface profile as it is well known that SEM images can be<br />

misleading in identifying peak or kink features.<br />

EHT=20.00 kV<br />

WD=10.0 mm<br />

Signal A=SE1<br />

Mag=200x<br />

Fig. D9 – SEM images of samples L25b a), L35 b)<br />

The SEM and AFM analyses revealed some differences in the and L40 c)<br />

samples. A specific work devoted to identifying the<br />

correlation between excess of heat and the characteristics of the samples, now in progress, should lead<br />

to identification of the characteristics of the rough material capable of producing Pd cathodes with a<br />

further increasing of the reproducibility of excess power production.<br />

100 µm<br />

L40<br />

100 µm EHT = 20.00 kV Signal A=SE1<br />

WD = 10.0 mm Mag=200x<br />

c)<br />

[D11] V. Violante et al., Some recent results at <strong>ENEA</strong>, Proc. XII Inter. Conference on Cold Fusion (Yokohama 2005), p. 117<br />

[D12] D. Gozzi et al., J. Electroanal. Chem. 452, 253 (1998)<br />

[D13] M. McKubre et al., The emergence of a coherent explanation for anomalies observed in D/Pd and H/Pd systems: evidences for 4 He and<br />

3 H production, Proc. VIII Inter. Conference on Cold Fusion (Lerici 2000), p 3<br />

[D14] M. Miles et al., J. Electroanal. Chem. 346, 99 (1993)<br />

References<br />

151<br />

Progress Report 2006


December 2006<br />

Organisation Chart<br />

Coordinamento Trasferimento<br />

Tecnologico<br />

Francesco De Marco<br />

Nucleo di Agenzia<br />

Paola Batistoni<br />

Unità Supporto Tecnico Gestionale FUS<br />

Nicola Manganiello<br />

DIREZIONE<br />

Alberto Renieri<br />

*<br />

*<br />

*<br />

Coordinamento Funzionale<br />

Giovanni Coccoluto<br />

Unità Supporto Tecnico Gestionale RAD<br />

Pasquale Di Giamberardino<br />

*EURATOM - <strong>ENEA</strong> Association<br />

Progress Report 2006<br />

152


Sezione Fisica della <strong>Fusione</strong> a Confinamento<br />

Magnetico<br />

Alberto Renieri a.i.<br />

Sezione Tecnologie della <strong>Fusione</strong><br />

Aldo Pizzuto<br />

Sezione Ingegneria Elettrica ed Elettronica<br />

Alberto Coletti<br />

Sezione Gestione Grandi Impianti Sperimentali<br />

Giuseppe Mazzitelli<br />

Sezione Superconduttività<br />

Antonio della Corte<br />

Gruppo Fisica e Tecnologie del Confinamento<br />

Inerziale<br />

Carmela Strangio<br />

Sezione Ingegneria Sperimentale<br />

Gianluca Benamati<br />

*<br />

*<br />

*<br />

*<br />

*<br />

*<br />

*<br />

Sezione Esercizio Impianti - Casaccia<br />

Corrado Kropp a.i.<br />

Sezione Esercizio Impianti - Trisaia<br />

Corrado Kropp a.i.<br />

Sezione Esercizio Impianti - Saluggia<br />

Corrado Kropp a.i.<br />

Sezione Sorgenti Radiazioni e Applicazioni di<br />

Radiazioni Ionizzanti<br />

Armando Festinesi<br />

Sezione Sistemi Nucleari Innovativi e Chiusura Ciclo<br />

Nucleare<br />

Renato Tinti<br />

Laboratorio Caratterizzazione Rifiuti Radioattivi<br />

Natale Sparacino<br />

153<br />

Progress Report 2006


Abbreviations and Acronyms<br />

ACP<br />

AFM<br />

ALE<br />

ALISIA<br />

APSA<br />

AS<br />

ASDEX<br />

ASDEX-U<br />

ASTEX<br />

BA<br />

BAE<br />

BNCT<br />

BOC<br />

CD<br />

CDP<br />

CEA<br />

CERN<br />

CFC<br />

CHF<br />

CICC<br />

CIRTEN<br />

CMS<br />

CNR<br />

COMPASS-D<br />

CODAS<br />

CPS<br />

CPS<br />

CRPP<br />

CS<br />

CSU<br />

CT/CAT<br />

Cyric<br />

CVD<br />

DAS<br />

DEMO<br />

DCLL<br />

DIS<br />

DISCORAP<br />

DL<br />

DRP<br />

DIII-D<br />

DTL<br />

DVT<br />

DW<br />

activated corrosion product<br />

atomic force microscopy<br />

abrupt large-amplitude event<br />

Assessment of Liquid Salts for Innovative Applications<br />

ageing probabilistic safety assessment<br />

angular scanning<br />

Axisymmetric Divertor Experiment - Garching - Germany<br />

Axisymmetric Divertor Experiment Upgrade - Garching - Germany<br />

Advanced Stability Experiment<br />

Broader Approach<br />

beta-induced Alfvén eigenmode<br />

boron neutron capture therapy<br />

beginning of cycle<br />

current drive<br />

collector depressed potential<br />

Commissariat à l’Energie Atomique - France<br />

Organisation Europeénne pour la Recherche Nucléaire- Geneva<br />

carbon fibre composite<br />

critical heat flux<br />

cable-in-conduit conductor<br />

Consortium for Research in Nuclear Technologies<br />

common manipulator system<br />

Consiglio Nazionale delle Ricerche - Italy<br />

is a highly flexible, medium-sized tokamak - Culham<br />

control and data acquisition system<br />

coolant purification system<br />

capillary porous system<br />

Centre de Recherches en Physique des Plasmas - Villigen - Switzerland<br />

central solenoid<br />

Close Support Unit<br />

computerized (axial) tomography<br />

Cyclotron and Radioisotope Centre - Tohoku University - Japan<br />

chemical vapour deposition<br />

data acquisition system<br />

demonstration/prototype reactor<br />

dual coolant lithium-lead<br />

data one-step<br />

Dipoli Super Conduttori Rapidamente Pulsati (INFN) - Frascati<br />

dome liner<br />

Divertor Refurbishment Platform - <strong>ENEA</strong> - Brasimone<br />

Doublet III - D-shape. Tokamak at General Atomics - San Diego - USA<br />

drift tube linac<br />

divertor vertical target<br />

drift waves<br />

EAF<br />

EBSD<br />

EC<br />

ECCD<br />

European Activation File<br />

electron backscattering diffraction<br />

electron cyclotron<br />

electron cyclotron current drive<br />

Progress Report 2006<br />

154


ECH<br />

ECR<br />

ECRH<br />

EC WGB<br />

ECT/TCT<br />

ECT/TCT<br />

EDA<br />

EDS<br />

EFDA<br />

EFIT<br />

EFF<br />

EISOFAR<br />

ELD<br />

ELM<br />

ELSY<br />

em<br />

EN-TRAP<br />

EOC<br />

EOL<br />

EP<br />

EPM<br />

ETD<br />

EUROPART<br />

EUROTRANS<br />

electron cyclotron heating<br />

electron cyclotron resonance<br />

electron cyclotron resonance heating<br />

electron cyclotron wave Gaussian beam<br />

emission & transmission tomography<br />

electrical capacitance tomography/transmission computer tomography<br />

Engineering Design Activities<br />

electron dispersion spectroscopy<br />

European Fusion Development Agreement<br />

European facility on an industrial-scale transmuter<br />

European fusion file<br />

European Innovative Sodium-Cooled Fast Reactor<br />

electron Landau damping<br />

edge localised modes<br />

European lead-cooled system<br />

electromagnetic<br />

European Network of Testing Facilities for the Quality Checking of Radioactive Waste Packages<br />

end of cycle<br />

end of life<br />

Enhanced Programme (JET)<br />

energetic particle mode<br />

European Transmutation Demonstrator<br />

European Research Programme for the Partitioning of Minor Actinides<br />

European Transmutation<br />

FC<br />

FCS<br />

FDB<br />

FEB<br />

FEM<br />

FIGEX<br />

FMEA<br />

FMECA<br />

FNG<br />

FNS<br />

FPS<br />

FRTC<br />

FTU<br />

FWHM<br />

FWP<br />

FZK<br />

fission chamber<br />

flux-core spheromak<br />

fuel dissolution basket<br />

fast electron bremsstrahlung<br />

finite-element method/model<br />

Fast Ion Generation Experiment<br />

failure mode and effect analaysis<br />

Failure Mode, Effects, and Criticality Analysis<br />

Frascati neutron generator - <strong>ENEA</strong><br />

Fusion Neutronics Source - JAERI - Japan<br />

fuel pin simulator<br />

fast ray tracing code<br />

Frascati Tokamak Upgrade - <strong>ENEA</strong><br />

full width at half maximum<br />

first-wall panel<br />

Forschungszeuntrum - Karlsruhe - Germany<br />

GAM<br />

GNEP<br />

GRTN<br />

GSI<br />

GSSR<br />

geodesic acoustic mode<br />

Global Nuclear Energy Partnership<br />

National Grid Regulator<br />

Gesellschaft fuer Schwerionenforschung - Darmstadt, Germany<br />

Generic-Site Specific Safety Report<br />

HCLL<br />

HCPB<br />

HEBT<br />

HHFT<br />

HLM<br />

helium-cooled lithium-lead<br />

helium-cooled pebble bed<br />

high-energy beam transport<br />

high heat flux testing<br />

heavy liquid meta<br />

155<br />

Progress Report 2006


Abbreviations and<br />

HL-1Ml<br />

HRP<br />

HRTS<br />

HS<br />

HTS<br />

HX<br />

Circular cross section tokamak modified from HL-1 - Centre for Fusion Science - China<br />

hot radial pressing<br />

high-resolution Thomson scattering<br />

heat source<br />

high-temperature superconductor<br />

heat exchanger<br />

IAEA<br />

I&D<br />

IBW<br />

ICE<br />

ICRH<br />

IDM<br />

IE<br />

IEA<br />

IFE<br />

IFMIF<br />

IMF<br />

INFN-LNL<br />

INTD<br />

IP<br />

IRIS<br />

ISPESL<br />

ISOCS<br />

ITASE<br />

ITB<br />

ITER<br />

ITG<br />

IVT<br />

IVVS<br />

International Atomic Energy Agency - Vienna - Austria<br />

instrumentation and control<br />

ion Bernstein wave<br />

Integral Circulation Experiment<br />

ion cyclotron resonance heating<br />

ITER Documentation Management<br />

Institute for Energy - Petten - the Netherlands<br />

International Energy Agency<br />

inertial fusion energy<br />

International Fusion Materials Irradiation Facility<br />

inert matrix fuel<br />

Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro<br />

International Near-Term Deployment<br />

industrial packaging<br />

International Reactor Innovative and Secure<br />

Institute of Occupational Safety, Health and Prevention<br />

In-situ object counting system<br />

International Trans Antarctic Scientific Expedition<br />

internal transport barrier<br />

International Thermonuclear Experimental Reactor<br />

ion temperature gradient<br />

inner vertical target<br />

in-vessel viewing and ranging system<br />

JAEA<br />

JET<br />

JIPPT-IIU<br />

JRAs<br />

JRC<br />

JT-60U<br />

Japan Atomic Energy Agency - Japan<br />

Joint European Torus - Abingdon - U.K.<br />

Japanese Institute of Plasma Physics Torus-II Upgrade<br />

Joint Research Activities<br />

Joint Research Centre - Ispra - Italy<br />

JAERI Tokamak 60 Upgrade, Naka, Japan<br />

KH<br />

KIZ<br />

Kelvin Helmholtz<br />

Karlsruhe Isochronous Cyclotron<br />

LANL<br />

LBC<br />

LBE<br />

LCA<br />

LED<br />

LFR<br />

LH<br />

LHC<br />

LHCD<br />

LHW<br />

LIDAR-TS<br />

LLL<br />

Los Alamos National Laboratory<br />

liquid bismuth cathode<br />

lead bismith eutectic<br />

life cycle assessment<br />

light emitting diode<br />

Lead-Cooled Fast Reactor<br />

lower hybrid<br />

Large Hadran Collider (CERN)<br />

lower hybrid current drive<br />

lower hybrid wave<br />

laser imaging detection and ranging - Thomson scattering<br />

liquid lithium limiter<br />

Progress Report 2006<br />

156


Acronyms<br />

LLRN<br />

LNL<br />

LOFT<br />

LWR<br />

long-lived radionuclides<br />

Legnano National Laboratory<br />

loss-of fluid test<br />

light-water reactor<br />

MA<br />

MARFE<br />

MAST<br />

MHD<br />

MIUR<br />

MOD<br />

MSE<br />

MSE<br />

minor actinides<br />

multifaceted asymmetric radiation from the edge<br />

Mega Ampère Spherical Tokamak<br />

magnetohydrodynamic<br />

Italian Ministry of Higher Education and Research<br />

metal-organic deposition<br />

motional Stark effect<br />

Italian Ministry of Economic Development<br />

NAR<br />

Nuclear Analysis Report<br />

NAs<br />

Networking Activities<br />

NBI<br />

neutral beam injection<br />

NEA<br />

Nuclear Energy Agency (Paris, France)<br />

NEA<br />

standing committees (NSC - Nuclear Science; NDC - Nuclear Development; CSNI - Safety of Nuclear Installation; RWMC<br />

- - Radioactive Waste Management; CRPPH - Radiation Protection and Public Health)<br />

NETL<br />

Nuclear Engineering Teaching Laboratory - Texas - U.S.A.<br />

NNB<br />

negative neutral beam<br />

NTA<br />

neutron test area<br />

NTM<br />

neoclassial tearing mode<br />

NRG<br />

Nuclear Research Counsultancy Group - Petten - The Netherlands<br />

OCS<br />

ODE<br />

ONRG<br />

ORE<br />

ORNL<br />

OVT<br />

oxygen control system<br />

ordinary differential equation<br />

Office of Naval Research Global<br />

occupational radiation exposure<br />

Oak Ridge National Laboratory - Tennessee - U.S.A.<br />

outer vertical target<br />

PATEROS<br />

PCB<br />

PBC<br />

PD<br />

PDE<br />

PDI<br />

PET<br />

PF<br />

PFC<br />

PFCT<br />

PFW<br />

PIE<br />

PIT<br />

PLD<br />

PMT<br />

PPCS<br />

PRA<br />

PRF<br />

PRHH<br />

PSI<br />

PWR<br />

Partitioning and Transmutation European Roadmap for Sustainable Nuclear Energy<br />

polychlorobiphenyls<br />

pre-brazed casting<br />

power density<br />

partial differential equation<br />

parametric decay instability<br />

pin expansion tool<br />

poloidal field<br />

plasma-facing component<br />

plasma-facing component transporter<br />

primary first-wall<br />

postulated initiating event<br />

powder-in-tube<br />

pulsed-laser deposition<br />

photomultiplier tube<br />

Power Plant Conceptual Studies<br />

probabilistic risk assessment<br />

permeation reduction factor<br />

preliminary remote handling handbook<br />

Physiological Strain Index<br />

pressurised water reactor<br />

157<br />

Progress Report 2006


Abbreviations and<br />

QA<br />

quality assurance<br />

RABiTS<br />

RACE<br />

RAPHAEL<br />

RD<br />

rf<br />

RFQ<br />

RFX<br />

RH<br />

RO<br />

RT<br />

rolling-assisted biaxially texture of substrate<br />

Reactor-Accelerator Coupling Experiments<br />

Reactor for Process Heat, Hydrogen and Electricity Generation<br />

rolling direction<br />

radiofrequency<br />

radiofrequency quadrupole<br />

Reversed Field Pinch Experiment - Padua - Italy (Association EURATOM-<strong>ENEA</strong>)<br />

remote handling<br />

responsible officer<br />

room temperature<br />

S/A<br />

SCD<br />

SEM<br />

SFE<br />

SGS<br />

SOL<br />

SP<br />

SPES<br />

SRWGA<br />

SSC<br />

SSQLFP<br />

ST<br />

subassembly<br />

single crystal diamond<br />

scanning electron microscopy<br />

stacking fault energy<br />

segmented gamma scanner<br />

scrape-off layer<br />

screw pinch<br />

Study for the Production of Exotic Species<br />

SEA radioactive-waste gamma analyser<br />

solid steel cathode<br />

steady-state quasi-linear Fokker-Planck<br />

spherical torus<br />

TAa<br />

TAE<br />

TALDICE<br />

TBM<br />

TES<br />

TEPC<br />

Transnational Access Activities<br />

toroidicity-induced Alfvén eigenmode<br />

Talos Dome Ice<br />

test blanket module<br />

tritium extraction system<br />

tissue-equivalent proportional counters<br />

TEXTOR Torus Experiment for Technology Oriented Research. Tokamak at Jülich Germany (Association EURATOM –<br />

FZJ)<br />

TFA<br />

trifluoroacetate<br />

TFAS<br />

toroidal field advaced strands<br />

TFC<br />

toroidal field power<br />

TIG<br />

tungsten inert gas<br />

TITG<br />

trapped ion ITG<br />

TOFOR<br />

time-of-flight neutron spectrometer optimized for high counting rate<br />

TPR<br />

tritium permeation rate<br />

TRADE<br />

TRIGA Accelerator-Driven Experiment - <strong>ENEA</strong>- Casaccia<br />

TS<br />

Thomson scattering<br />

TUCN<br />

Technical Universitry of Cluj-Naoica - Romania<br />

TUD<br />

Technical University of Dresden - Germany<br />

UCI<br />

UKAEA<br />

UT<br />

University of California at Irvine - Usa<br />

United Kingdom Atomic Energy Agency<br />

University of Texas - USA<br />

VELLA<br />

VDS<br />

VHTR<br />

Virtual European Lead Initiative<br />

vent detritiation system<br />

Very High Temperature Reactor<br />

Progress Report 2006<br />

158


Acronyms<br />

VMS<br />

VSM<br />

VTA<br />

vertical module segmentation<br />

vibrating sample magnetometer<br />

vertical target assembly<br />

WKB<br />

Wenzel, Kramer, Brillouin code<br />

XRD<br />

ZF<br />

ZFC<br />

x-ray diffraction<br />

zonal flow<br />

zero field cooling<br />

159<br />

Progress Report 2006


2006<br />

<strong>PROGRESS</strong> <strong>REPORT</strong>

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