PROGRESS REPORT - ENEA - Fusione
PROGRESS REPORT - ENEA - Fusione
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 />
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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 />
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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 />
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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 />
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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 />
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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>