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nucmag.com<br />

<strong>2018</strong><br />

2<br />

81<br />

Gas Cooled<br />

Reactor Development<br />

in China<br />

85 ı Environment and Safety<br />

Severe Accident Safety Research for Reactor Buildings<br />

95 ı Operation and New Build<br />

Knowledge Management and TRIZ for Safe Shutdown Capability<br />

ISSN · 1431-5254<br />

24.– €<br />

104 ı Decommissioning and Waste Management<br />

Corrosion Processes of Alloyed Steels in Salt Solutions<br />

134 ı Nuclear Today<br />

Playing Politics with Nuclear is all Part of the Game


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

Some Questions and Answers<br />

About Energy<br />

Dear Reader, The question is always on the agenda whether people are really aware about facts on energy.<br />

The following energy quiz with 12 questions should point out some interesting facts. The answers are given on page 132<br />

of this issue of <strong>atw</strong>.<br />

1. True or false:<br />

The global energy demand will<br />

decrease in the next decades!<br />

a. True<br />

b. False<br />

2. True or false:<br />

The global electricity demand will<br />

decrease in the next decades!<br />

a. True<br />

b. False<br />

3. True or false:<br />

The global coal production<br />

is always decreasing!<br />

a. True<br />

b. False<br />

4. What percentage of world’s electricity<br />

production was produced from nuclear<br />

in 2017?<br />

a. 1 %<br />

b. 6 %<br />

c. 11 %<br />

d. 20 %<br />

8. Which technology has the lowest<br />

CO 2 footprint?<br />

a. Photovoltaics<br />

b. Wind<br />

c. Nuclear<br />

d. Hydropower<br />

9. What energy source has Bill Gates<br />

invested in, and championed, over the<br />

last few years?<br />

a. Nuclear power<br />

b. Photovoltaics<br />

c. Wind energy<br />

d. Tidal energy<br />

10. What energy source has the smallest<br />

number of lost lifetime-days<br />

(due to health hazards and accidents)<br />

per kilowatt-hour produced?<br />

a. Coal<br />

b. Natural gas<br />

c. Wind<br />

d. Nuclear power<br />

11. What subjects someone<br />

to the most radiation?<br />

71<br />

EDITORIAL<br />

5. What percentage of world’s electricity<br />

production was produced from wind plus<br />

solar in 2017?<br />

a. 1 %<br />

b. 5 %<br />

c. 10 %<br />

d. 20 %<br />

6. Which country has the most<br />

fossil fuel resources?<br />

a. Saudi Arabia<br />

b. Russia<br />

c. United States of America<br />

d. China<br />

e. EU<br />

7. What country/region will emit the most<br />

carbon dioxide in <strong>2018</strong>?<br />

a. Living next to a nuclear power plant.<br />

b. Flying from Europe to other continents<br />

c. Eating a 250 g bag of potato chips<br />

every day<br />

d. Living in Guarapari, Brazil<br />

12. True or false:<br />

The number of nuclear power plants<br />

worldwide will decrease in the future.<br />

a. True<br />

b. False<br />

Christopher Weßelmann<br />

– Editor in Chief –<br />

a. United States of America<br />

b. Nigeria<br />

c. EU<br />

d. China<br />

Editorial<br />

Some Questions and Answers About Energy


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

72<br />

EDITORIAL<br />

Einige Fragen und Antworten<br />

zum Thema Energie<br />

Liebe Leserin, lieber Leser, Diskussion über das Thema Energie wird häufig die Frage aufgeworfen, inwieweit<br />

diese von Fakten bestimmt wird bzw. die Fakten überhaupt bekannt sind. Das folgende Energiequiz soll mit seinen<br />

12 Fragen einige interessante Fakten aufzeigen. Die Antworten finden Sie auf Seite 132 dieser Ausgabe der <strong>atw</strong>.<br />

1. Richtig oder falsch:<br />

Der globale Energiebedarf wird<br />

in den nächsten Jahrzehnten sinken!<br />

a. Wahr<br />

b. Falsch<br />

2. Richtig oder falsch:<br />

Der weltweite Strombedarf wird<br />

in den nächsten Jahrzehnten sinken!<br />

a. Wahr<br />

b. Falsch<br />

3. Richtig oder falsch:<br />

Die weltweite Kohleförderung nimmt ab!<br />

8. Welche Technologie hat den niedrigsten<br />

CO 2 -Fußabdruck?<br />

a. Photovoltaik<br />

b. Wind<br />

c. Kernenergie<br />

d. Wasserkraft<br />

9. In welche Energiequelle hat Bill Gates<br />

in den letzten Jahren investiert und sich<br />

dafür öffentlich eingesetzt?<br />

a. Kernkraft<br />

b. Photovoltaik<br />

c. Windenergie<br />

d. Gezeitenenergie<br />

a. Wahr<br />

b. Falsch<br />

4. Welchen Anteil hatte die Kernenergie<br />

an der weltweiten Stromproduktion<br />

im Jahr 2017?<br />

a. 1 %<br />

b. 6 %<br />

c. 11 %<br />

d. 20 %<br />

5. Welchen Anteil hatten Wind und Sonne<br />

an der weltweiten Stromproduktion<br />

im Jahr 2017?<br />

a. 1 %<br />

b. 5 %<br />

c. 10 %<br />

d. 20 %<br />

6. Welches Land verfügt über die größten<br />

fossilen Energieressourcen?<br />

a. Saudi-Arabien<br />

b. Russland<br />

c. Vereinigte Staaten von Amerika<br />

d. China<br />

e. EU<br />

7. Welches Land bzw. welche Region<br />

wird <strong>2018</strong> die höchsten Kohlendioxidemissionen<br />

verzeichnen?<br />

a. Vereinigte Staaten von Amerika<br />

b. Nigeria<br />

c. EU<br />

d. China<br />

10. Welche Energiequelle verzeichnet die<br />

geringste Anzahl an Ausfalltagen<br />

(aufgrund von Gesundheitsgefahren<br />

und Unfällen) pro produzierter Kilowattstunde?<br />

a. Kohle<br />

b. Erdgas<br />

c. Wind<br />

d. Kernkraft<br />

11. Was verursacht die höchste<br />

Strahlenbelastung?<br />

a. Wohnen neben einem Kernkraftwerk.<br />

b. Fliegen von Europa<br />

zu anderen Kontinenten<br />

c. Täglich 250 g Chips essen<br />

d. Leben in Guarapari, Brasilien<br />

12. Richtig oder falsch:<br />

Die Zahl der Kernkraftwerke weltweit<br />

wird in Zukunft abnehmen.<br />

a. Wahr<br />

b. Falsch<br />

Christopher Weßelmann<br />

– Chefredakteur –<br />

Editorial<br />

Einige Fragen und Antworten zum Thema Energie


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<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

74<br />

Issue 2<br />

February<br />

CONTENTS<br />

81<br />

Gas Cooled<br />

Reactor Development<br />

in China<br />

| | Outside view of the two boiling water reactors at the Olkiluoto site in Finland. The reactors with a gross electric output of 910 MWe each<br />

are successfully operated by Teollisuuden Voima Oyj – TVO. Ever since the early 1990s, the OL1 and OL2 capacity factors have remained<br />

between 93 and 97 percent. (Courtesy: TVO)<br />

Editorial<br />

Some Questions and Answers<br />

About Energy 71<br />

Einige Fragen und Antworten<br />

zum Thema Energie 72<br />

Abstracts | English 76<br />

Abstracts | German 77<br />

Calendar . . . . . . . . . . . . . . . . . . . . . . . .80<br />

Energy Policy, Economy and Law<br />

Development of High Temperature<br />

Gas Cooled Reactor in China 81<br />

Wentao Guo and Michael Schorer<br />

Spotlight on Nuclear Law<br />

The Liability According to § 26 of the<br />

German Atomic Energy Act – A Wallflower? 84<br />

Die Haftung nach § 26 AtG –<br />

ein Mauerblümchen? 84<br />

Christian Raetzke<br />

81<br />

| | The construction of Shidao Bay HTGR.<br />

Inside Nuclear with NucNet<br />

WANO to Increase Focus on New Nuclear as<br />

Industry’s Centre of Gravity Shifts Towards Asia 78<br />

85<br />

NucNet<br />

| | COCOSYS nodalisation scheme.<br />

DAtF Notes. . . . . . . . . . . . . . . . . . . . . . 79<br />

Contents


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

Environment and Safety<br />

Investigation of Conditions Inside the Reactor<br />

Building Annulus of a PWR Plant of KONVOI<br />

Type in Case of Severe Accidents with Increased<br />

Containment Leakages 85<br />

Ivan Bakalov and Martin Sonnenkalb<br />

Sensitivity Analysis of MIDAS Tests<br />

Using SPACE Code: Effect of Nodalization 90<br />

Shin Eom, Seung-Jong Oh and Aya Diab<br />

75<br />

CONTENTS<br />

90<br />

Operation and New Build<br />

The Application of Knowledge Management<br />

and TRIZ for solving the Safe Shutdown Capability<br />

in Case of Fire Alarms in Nuclear Power Plants 95<br />

Chia-Nan Wang, Hsin-Po Chen, Ming-Hsien Hsueh and Fong-Li Chin<br />

95<br />

| | Isometric View of the MIDAS Facility.<br />

| | Application of knowledge management and TRIZ.<br />

Decommissioning and Waste Management<br />

Corrosion Processes of Alloyed Steels<br />

in Salt Solutions 104<br />

Bernhard Kienzler<br />

Research and Innovation<br />

Design and Development of a Radio eco logical<br />

Domestic User Friendly Code for Calculation<br />

of Radiation Doses and Concentration<br />

due to Airborn Radio nuclides Release During<br />

the Accidental and Normal Operation<br />

in Nuclear Installations 111<br />

|104<br />

111<br />

| | Localized corrosion phenomena of steel 1.4306.<br />

Events<br />

Event Report:<br />

Nuklearforum Schweiz – Future Management<br />

– Key Solutions for Nuclear Facilities 121<br />

Event Report:<br />

Nuklearforum Schweiz – Zukunftsmanagement<br />

– zentrale Lösungsansätze für Kernanlagen 121<br />

Matthias Rey<br />

KTG Inside . . . . . . . . . . . . . . . . . . . . . . 123<br />

News . . . . . . . . . . . . . . . . . . . . . . . . . 129<br />

Nuclear Today<br />

Playing Politics with Nuclear<br />

is All Part of the Game 134<br />

John Shepherd<br />

Imprint 110<br />

| Summary of Code Algorithms.<br />

A. Haghighi Shad, D. Masti, M. Athari Allaf, K. Sepanloo, S.A.H. Feghhi<br />

and R. Khodadadi<br />

AMNT <strong>2018</strong>: Registration Form . . . . . . . . . . . Insert<br />

Contents


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

76<br />

ABSTRACTS | ENGLISH<br />

WANO to Increase Focus on New Nuclear<br />

as Industry’s Centre of Gravity Shifts<br />

Towards Asia<br />

NucNet | Page 78<br />

The World Association of Nuclear Operators<br />

(WANO) intends to focus more on new nuclear units<br />

coming into operation around the world as the<br />

“ centre of gravity” in the industry shifts from the US<br />

and Europe to the Middle East and Asia. The<br />

organisation’s chief executive officer, Peter Prozesky,<br />

told NucNet that new-build projects in China, India,<br />

Turkey and the United Arab Emirates are giving<br />

WANO the opportunity to make sure those countries<br />

start the operational life of their new units “in a very<br />

positive way”. In supporting countries with new<br />

units beginning operation, WANO is working more<br />

closely with the International Atomic Energy Agency<br />

(IAEA). One of the IAEA’s tasks is to help emerging<br />

nuclear countries develop the infrastructure and<br />

capability they need to have nuclear power as part of<br />

their energy mix.<br />

Development of High Temperature Gas<br />

Cooled Reactor in China<br />

Wentao Guo and Michael Schorer | Page 81<br />

High temperature gas cooled reactor (HTGR) is one<br />

of the six Generation IV reactor types put forward<br />

by Generation IV International Forum (GIF) in<br />

20<strong>02</strong>. This type of reactor has high outlet temperature.<br />

It uses Helium as coolant and graphite as<br />

moderator. Pebble fuel and ceramic reactor core are<br />

adopted. Inherit safety, good economy, high generating<br />

efficiency are the advantages of HTGR.<br />

According to the comprehensive evaluation from<br />

the international nuclear community, HTGR has<br />

already been given the priority to the research and<br />

development for commercial use. A demonstration<br />

project of the High Temperature Reactor-Pebblebed<br />

Modules (HTR-PM) in Shidao Bay nuclear<br />

power plant in China is under construction. In this<br />

paper, the development history of HTGR in China<br />

and the current situation of HTR-PM will be introduced.<br />

The experiences from China may be taken as<br />

a reference by the international nuclear community.<br />

The Liability According to § 26 of the<br />

German Atomic Energy Act – A Wallflower?<br />

Christian Raetzke | Page 84<br />

According to German law, liability for damage<br />

caused by radioactivity can arise from several<br />

regulation. In most cases, liability under the Paris<br />

Convention on Third Party Liability in the Field of<br />

Nuclear Energy, which applies in the field of nuclear<br />

power, is at the forefront of discussion. According to<br />

§ 26 of the German Atomic Energy Act, liability is<br />

somewhat in the shadow of the Paris Convention. It<br />

applies to the handling of radioactivity in medicine,<br />

research and industry (e. g. for test emitters) as well<br />

as activities involving natural and depleted uranium<br />

and nuclear fusion. The article outlines the basic<br />

elements of liability under Section 26 of the German<br />

Atomic Energy Act, which may become increasingly<br />

important in future due to recent developments<br />

such as the phasing out of nuclear power in<br />

Germany.<br />

Investigation of Conditions Inside the<br />

Reactor Building Annulus of a PWR Plant of<br />

KONVOI Type in Case of Severe Accidents<br />

with Increased Containment Leakages<br />

Ivan Bakalov and Martin Sonnenkalb | Page 85<br />

Improvements of the implemented severe accident<br />

management (SAM) concepts have been done in all<br />

operating German NPPs after the Fukushima Daiichi<br />

accidents following recommendations of the<br />

German Reactor Safety Commission (RSK) and as a<br />

result of the stress test being performed. The<br />

efficiency of newly developed severe accident<br />

management guidelines (SAMG) for a PWR KONVOI<br />

reference plant related to the mitigation of challenging<br />

conditions inside the reactor building (RB)<br />

annulus due to increased containment leakages<br />

during severe accidents have been assessed. Based<br />

on two representative severe accident scenarios the<br />

releases of both hydrogen and radionuclides into the<br />

RB annulus have been predicted with different<br />

boundary conditions. The accident scenarios have<br />

been analysed without and with the impact of<br />

several SAM measures (already planned or proposed<br />

in addition), which turned out to be efficient to<br />

mitigate the consequences. The work was done<br />

within the frame of a research project financially<br />

supported by the Federal Ministry BMUB.<br />

Sensitivity Analysis of MIDAS Tests Using<br />

SPACE Code: Effect of Nodalization<br />

Shin Eom, Seung-Jong Oh and Aya Diab | Page 90<br />

The nodalization sensitivity analysis for the ECCS<br />

(Emergency Core Cooling System) bypass phenomena<br />

was performed using the SPACE (Safety<br />

and Performance Analysis CodE) thermal hydraulic<br />

analysis computer code. The results of MIDAS<br />

(Multi- dimensional Investigation in Downcomer<br />

Annulus Simulation) test were used. The MIDAS<br />

test was conducted by the KAERI (Korea Atomic<br />

Energy Research Institute) for the performance<br />

evaluation of the ECC (Emergency Core Cooling)<br />

bypass phenomenon in the DVI (Direct Vessel<br />

Injection) system. The main aim of this study is to<br />

examine the sensitivity of the SPACE code results<br />

to the number of thermal hydraulic channels<br />

used to model the annulus region in the MIDAS<br />

experiment. The numerical model involves three<br />

nodalization cases (4, 6, and 12 channels) and<br />

the result show that the effect of nodalization<br />

on the bypass fraction for the high steam flow rate<br />

MIDAS tests is minimal. For computational<br />

efficiency, a 4 channel representation is recommended<br />

for the SPACE code nodalization. For the<br />

low steam flow rate tests, the SPACE code overpredicts<br />

the bypass fraction irrespective of the<br />

nodalization finesse. The over- prediction at low<br />

steam flow may be attributed to the difficulty<br />

to accurately represent the flow regime in the<br />

vicinity of the broken cold leg.<br />

The Application of Knowledge<br />

Management and TRIZ for solving<br />

the Safe Shutdown Capability in Case of<br />

Fire Alarms in Nuclear Power Plants<br />

Chia-Nan Wang, Hsin-Po Chen,<br />

Ming-Hsien Hsueh and Fong-Li Chin | Page 95<br />

The Fukushima nuclear disaster in 2011 has raised<br />

widespread concern over the safety of nuclear<br />

power plants. This study employed knowledge<br />

management in conjunction with the Teoriya<br />

Resheniya Izobreatatelskih Zadatch (TRIZ) method<br />

in the formulation of a database to facilitate the<br />

evaluation of post-fire safe shutdown capability<br />

with the aim of safeguarding nuclear facilities in the<br />

event of fire. The proposed approach is meant to<br />

bring facilities in line with US Nuclear Regulatory<br />

Commission (NRC) standards. When implemented<br />

in a case study of an Asian nuclear power plant, our<br />

method proved highly effective in the detection of<br />

22 cables that fell short of regulatory requirements,<br />

thereby reducing 850,000 paths to 0. This study<br />

could serve as reference for industry and academia<br />

in the development of systematic approaches to the<br />

upgrading of nuclear power plants.<br />

Corrosion Processes of Alloyed Steels<br />

in Salt Solutions<br />

Bernhard Kienzler | Page 104<br />

A summary is given of the corrosion experiments<br />

with alloyed Cr-Ni steels in salt solutions performed<br />

at Research Centre Karlsruhe (today KIT), Institute<br />

for Nuclear Waste Disposal (INE) in the period<br />

between 1980 and 2004. Alloyed steels show<br />

significantly lower general corrosion in comparison<br />

to carbon steels. However, especially in salt brines<br />

the protective Cr oxide layers on the surfaces of<br />

these steels are disturbed and localized corrosion<br />

takes place. Data on general corrosion rates, and<br />

findings of pitting, crevice and stress corrosion<br />

cracking are presented.<br />

Design and Development of a Radioecological<br />

Domestic User Friendly Code for<br />

Calculation of Radiation Doses and Concentration<br />

due to Airborn Radionuclides<br />

Release During the Accidental and Normal<br />

Operation in Nuclear Installations<br />

A. Haghighi Shad, D. Masti,<br />

M. Athari Allaf, K. Sepanloo,<br />

S.A.H. Feghhi and R. Khodadadi | Page 111<br />

A domestic user friendly dynamic radiological dose<br />

and model has been developed to estimate radiation<br />

doses and stochastic risks due to atmospheric and<br />

liquid discharges of radionuclides in the case of a<br />

nuclear reactor accident and normal operation. In<br />

addition to individual doses from different pathways<br />

for different age groups, collective doses and<br />

stochastic risks can be calculated by the developed<br />

domestic user friendly KIANA Advance Computational<br />

Computer Code and model. The current Code<br />

can be coupled to any long-range atmospheric<br />

dispersion/short term model which can calculate<br />

radionuclide concentrations in air and on the<br />

ground and in the water surfaces predetermined<br />

time intervals or measurement data.<br />

Event Report: Future Management –<br />

Key Solutions for Nuclear Facilities<br />

Matthias Rey | Page 121<br />

Future management requires careful planning and<br />

knowledge of what options are available, how far<br />

optimizations make sense and which measures and<br />

process changes have already proven themselves<br />

elsewhere. The 2017 advanced course of the Swiss<br />

Nuclear Forum took up this topic. On the first day<br />

of the course, the focus was on solutions for<br />

optimizing system operation and maintenance. The<br />

second day focused on the employees in their<br />

changing environment. As a novelty this year, the<br />

topics of the morning input presentations were<br />

discussed in depth in workshops on both afternoons.<br />

Playing Politics with Nuclear is all Part<br />

of the Game<br />

John Shepherd | Page 134<br />

If a week is a long time in politics – a statement<br />

attributed to former British prime minister Harold<br />

Wilson – then what about a month, or several<br />

months – a period relevant for the use of nuclear<br />

power? The nuclear industry has long accepted that<br />

it can be used as a political football, to be kicked into<br />

goal or off the pitch completely depending on the<br />

situation at hand. Our industry therefore has power<br />

in the political sense too, but with power comes<br />

responsibility – nuclear leaders know that only too<br />

well and now is as good as time as ever to lead by<br />

example.<br />

Abstracts | English


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

WANO wird sich mit der Verlagerung der<br />

Aktivitäten nach Asien verstärkt auf den<br />

Kernkraftwerksneubau konzentrieren<br />

NucNet | Seite 78<br />

Die World Association of Nuclear Operators<br />

( WANO) will sich verstärkt auf Kernkraftwerksneubauten<br />

konzentrieren, da sich der „Schwerpunkt“<br />

der Branche von den USA und Europa in den Nahen<br />

Osten und nach Asien verlagert. Peter Prozesky,<br />

Chief Executive Officer von WANO, erläuterte, dass<br />

Neubauprojekte in China, Indien, der Türkei und<br />

den Vereinigten Arabischen Emiraten WANO die<br />

Möglichkeit geben, dass diese Länder mit den<br />

Erfahrungen von WANO in die Kernenergie einsteigen.<br />

Bei der Unterstützung von Ländern, in<br />

denen neue Anlagen in Betrieb genommen werden,<br />

arbeitet WANO eng mit der Internationalen Atomenergie-Organisation<br />

(IAEO) zusammen. Eine der<br />

Aufgaben der IAEO besteht darin, die zuküftigen<br />

Nuklearstaaten darin zu unterstützen, die Infrastruktur<br />

und das Know-how zu entwickeln, das<br />

sie benötigen, um die Kernenergie als Teil ihres<br />

Energiemixes zu nutzen.<br />

Entwicklung des gasgekühlten<br />

Hochtemperaturreaktors in China<br />

Wentao Guo und Michael Schorer | Seite 81<br />

Der gasgekühlte Hochtemperaturreaktor (HTGR) ist<br />

einer von sechs Reaktortypen der Generation IV, die<br />

20<strong>02</strong> vom Generation IV International Forum (GIF)<br />

vorgestellt wurde. Charakteristisch für diesen Reaktortyp<br />

sind die hohe Kühlmittelaustrittstem peratur<br />

aus dem Reaktor, Helium als Kühlmittel, Graphit<br />

als Moderator, kugelförmige Brenn elemente sowie<br />

keramischer Reaktorkernein bauten. Vorteile von<br />

HTGR sind inhärente Sicherheit, Wirtschaftlichkeit<br />

sowie hohe Effizienz der Brennstoffnutzung. Nach<br />

einer umfassenden Eva luierung durch hat die Entwicklung<br />

von HTGR bis hin zur kommerziellen<br />

Nutzung Priorität. Ein Demonstrationsprojekt für<br />

einen HTR-Modul reaktor befindet sich am Standort<br />

Shidao Bay in China in Bau. In diesem Beitrag<br />

werden die Entwicklungsgeschichte von HTGR in<br />

China und die aktuelle Situation der HTR-PM-<br />

Projekte vor gestellt. Die Erfahrungen aus China sind<br />

eine international nutzbare Referenz.<br />

Die Haftung nach § 26 AtG –<br />

ein Mauerblümchen?<br />

Christian Raetzke | Seite 84<br />

Die Haftung für Schäden aus Radioaktivität kann<br />

sich nach deutschem Recht aus mehreren Quellen<br />

ergeben. In der Diskussion steht meist die Haftung<br />

nach dem Pariser Übereinkommen (PÜ) im Vordergrund,<br />

die im Bereich der Kernenergie gilt. Etwas<br />

im Schatten des PÜ steht die Haftung nach § 26 AtG.<br />

Sie gilt für den Umgang mit Radioaktivität im<br />

Bereich der Medizin, Forschung und Industrie<br />

( etwa bei Prüfstrahlern) sowie für Aktivitäten rund<br />

um natürliches und abgereichertes Uran und für die<br />

Kernfusion. Der Artikel skizziert die Grund elemente<br />

der Haftung nach § 26 AtG, die aufgrund jüngerer<br />

Entwicklungen wie dem Kernenergieausstieg in<br />

Deutschland möglicherweise künftig an Bedeutung<br />

gewinnen wird.<br />

Untersuchungen zu den Zuständen im<br />

Ringraum des Reaktorgebäudes eine DWR<br />

vom Typ KONVOI im Falle von schweren<br />

Störfällen mit erhöhten Leckagen aus dem<br />

Containment<br />

Ivan Bakalov and Martin Sonnenkalb | Seite 85<br />

Die anlageninternen Notfallschutzkonzepte der in<br />

Betrieb befindlichen KKW in Deutschland wurden<br />

nach den Unfällen in Fukushima Daiichi verbessert<br />

und damit Empfehlungen der Reaktorsicherheitskommission<br />

(RSK) und neue Erkenntnisse aus den<br />

Stress Tests umgesetzt. Die Wirksamkeit von neu<br />

entwickelten Maßnahmen des mitigativen Notfallschutzes<br />

für eine DWR-Referenzanlage vom Typ<br />

KONVOI hinsichtlich der Zustände im Ringraum<br />

des Reaktorgebäudes bei erhöhten Leckagen aus<br />

dem Containment während schwerer Störfälle<br />

wurde analysiert. Die Freisetzung von Wasserstoff<br />

und Radionukliden in den Ringraum des Reaktorgebäudes<br />

wurde an Hand von zwei repräsentativen<br />

schweren Störfallszenarien unter der Annahme<br />

unterschiedlicher Randbedingungen untersucht.<br />

Die Analysen wurden ohne und mit mitigativen<br />

Notfallmaßnahmen (bereits umgesetzte oder<br />

zusätzliche Maßnahmen) durchgeführt, und die<br />

Ergebnisse bestätigten die Wirksamkeit aller Maßnahmen.<br />

Die Arbeiten wurden im Rahmen eines<br />

Forschungsprojektes der GRS finanziell unterstützt<br />

vom BMUB durchgeführt.<br />

Sensitivitätsanalyse von MIDAS-Tests mit<br />

SPACE-Code: Auswirkung der Nodalisierung<br />

Shin Eom, Seung-Jong Oh und Aya Diab | Seite 90<br />

Die Sensitivitätsanalyse zur Nodalisierung für die<br />

Bypass-Phänomene des ECCS (Emergency Core<br />

Cooling System) wurde mit Hilfe des thermo hydraulischen<br />

Analyse-Computercodes SPACE ( Safety and<br />

Performance Analysis CodE) durchgeführt. Dazu<br />

wurden die Ergebnisse des MIDAS-Tests (Multidimensional<br />

Investigation in Downcomer Annulus<br />

Simulation) verwendet. Der MIDAS-Test wurde vom<br />

KAERI (Korea Atomic Energy Research Institute) zur<br />

Leistungsbewertung des ECC ( Emergency Core<br />

Cooling) Bypass-Phänomens im DVI (Direct Vessel<br />

Injection) System durchgeführt. Das Hauptziel dieser<br />

Studie ist es, die Sensitivität der SPACE-Code-Ergebnisse<br />

für die thermo hydrau lischen Unterkanäle zu<br />

untersuchen, die zur Modellierung des Ringraums im<br />

MIDAS- Experiment verwendet werden. Aus Gründen<br />

der Rechen effizienz wird für die SPACE-Code-<br />

Nodalisierung eine 4-Kanal-Darstellung empfohlen.<br />

Knowledge Management und TRIZ<br />

für die Sicherstellung der Abschaltfähigkeit<br />

bei Feueralarmen in Kernkraftwerken<br />

Chia-Nan Wang, Hsin-Po Chen,<br />

Ming-Hsien Hsueh und Fong-Li Chin | Seite 95<br />

Die Katastrophe von Fukushima im Jahr 2011 hat<br />

die Frage nach der Sicherheit von Kernkraftwerken<br />

erneut gestellt. In dieser Studie wurde Wissensmanagement<br />

in Verbindung mit der Teoriya Resheniya<br />

Izobreatatelskih Zadatch (TRIZ) Methode bei der<br />

Formulierung einer Datenbank eingesetzt, um die<br />

Bewertung der Fähigkeit zur sicheren Abschaltung<br />

nach einem Brand in einem Kernkraftwerk zu<br />

ermöglichen. Der vorgeschlagene Ansatz zielt<br />

darauf ab, die Anlagen mit den Standards der<br />

US Nuclear Regulatory Commission (NRC) in<br />

Einklang zu bringen. Bei der Implementierung in<br />

einer Fallstudie eines asiatischen Kernkraftwerks<br />

erwies sich die Methode als sehr effektiv bei der<br />

Feststellung von 22 Kabeln, die nicht den vorgegebenen<br />

Anforderungen entsprachen, wodurch<br />

850.000 mögliche Ereignispfade auf 0 reduziert<br />

wurden. Diese Studie kann auch als Referenz<br />

dienen für die Entwicklung systematischer Ansätze<br />

zur weiteren Modernisierung von Kernkraftwerken.<br />

Korrosionprozesse legierter Stähle<br />

in Salzlösungen<br />

Bernhard Kienzler | Seite 104<br />

Es wird eine Zusammenfassung der Experimente<br />

zur Korrosion von legierten Cr-Ni Stählen in<br />

Salzlösungen vorgestellt. Die Experimente wurden<br />

Im Forschungszentrum Karlsruhe (heute KIT),<br />

Institut für Nukleare Entsorgung (INE) im Zeitraum<br />

zwischen 1980 und 2004 durchgeführt. Legierte<br />

Stähle zeigten eine deutlich geringere Flächenkorrosion<br />

im Vergleich zu den ebenfalls untersuchten<br />

Kohlenstoffstählen. Jedoch findet in den<br />

Salzlösungen eine Störung der Korrosionsschutzschichten<br />

aus Cr-Oxiden auf den Stahloberflächen<br />

statt, die zu lokalen Korrosionsprozessen führt.<br />

Flächenkorrosionsraten und die Beobachtungen<br />

hinsichtlich Lochfrass-, Spalt- und Spannungsrißkorrosion<br />

werden aufgezeigt.<br />

Entwicklung eines Codes zur Berechnung<br />

der Strahlendosis und -konzentration bei<br />

Freisetzung von luftgetragenen Radionukliden<br />

während des unfallbedingten<br />

und normalen Betriebes kerntechnischer<br />

Anlagen<br />

A. Haghighi Shad, D. Masti,<br />

M. Athari Allaf, K. Sepanloo,<br />

S.A.H. Feghhi und R. Khodadadi | Seite 111<br />

Zur Abschätzung von Strahlendosen und stochastischen<br />

Risiken durch atmosphärische und flüssige<br />

Radionuklidemissionen bei einem Reaktorunfall<br />

und im Normalbetrieb wurde ein benutzerfreundliches<br />

dynamisches radiologisches Freisetzungs- und<br />

Dosismodell entwickelt. Zusätzlich zu den Einzeldosen<br />

aus verschiedenen Pfaden für verschiedene<br />

Nuklide können Kollektivdosen und stochastische<br />

Risiken mit Hilfe des entwickelten benutzerfreundlichen<br />

KIANA Advance Computational Computer<br />

Codes und Modells berechnet werden. Der aktuelle<br />

Code kann mit jedem weiträumigen atmosphärischen<br />

Ausbreitungs-/Kurzzeitmodell gekoppelt<br />

werden, mit dem Radionuklidkonzentrationen<br />

in der Luft und am Boden und in Gewässern<br />

berechnet werden können.<br />

Tagungsbericht: Zukunftsmanagement –<br />

zentrale Lösungsansätze für Kernanlagen<br />

Matthias Rey | Seite 121<br />

Zukunftsmanagement erfordert sorgfältige Planung<br />

und Wissen darüber, welche Optionen zur Verfügung<br />

stehen, wieweit Optimierungen sinnvoll<br />

sind und welche Maßnahmen und Prozessänderungen<br />

sich allenfalls bereits anderswo<br />

bewährt haben. Der Vertiefungskurs 2017 des<br />

Nuklearforums Schweiz nahm diese Thematik auf.<br />

Im Zentrum standen Lösungsansätze zum Optimieren<br />

von Systembetrieb und Instandhaltung<br />

sowie die Mitarbeitenden in ihrer sich verändernden<br />

Umwelt. Als Novum wurden die Themen<br />

der Inputreferate des Vormittags in Workshops<br />

vertieft diskutiert.<br />

Mit der Kernenergie zu spielen<br />

ist Teil der Politik<br />

John Shepherd | Seite 134<br />

Eine Woche ist in der Politik eine lange Zeit! Dieser<br />

Satz wird dem ehemaligen britischen Premierminister<br />

Harold Wilson zugeschrieben. Was ist<br />

dann mit einem Monat oder mehreren Monaten,<br />

wie sie für eine langfristige Technologie wie der<br />

Kernenergie bestimmend sind? Die kerntechnische<br />

Industrie hat längst akzeptiert, dass sie als politischer<br />

Spielball genutzt werden kann, um je nach<br />

Situation ins Tor oder vom Spielfeld geschossen zu<br />

werden. „Nuklearpolitiker“ wissen, dass Entscheidungen<br />

zur Kernenergie nicht nur „Macht“<br />

bedeuten, sondern auch Verantwortung. Heute<br />

geht es deshalb darum hier mit gutem Beispiel<br />

voranzugehen.<br />

77<br />

ABSTRACTS | GERMAN<br />

Abstracts | German


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

78<br />

INSIDE NUCLEAR WITH NUCNET<br />

WANO to Increase Focus on New<br />

Nuclear as Industry’s Centre of Gravity<br />

Shifts Towards Asia<br />

NucNet<br />

The World Association of Nuclear Operators (WANO) intends to focus more on new nuclear units coming<br />

into operation around the world as the “centre of gravity” in the industry shifts from the US and Europe to<br />

the Middle East and Asia.<br />

The organisation’s chief executive officer, Peter Prozesky,<br />

told NucNet that new-build projects in China, India, Turkey<br />

and the United Arab Emirates are giving WANO the<br />

opportunity to make sure those countries start the<br />

operational life of their new units “in a very positive way”.<br />

He said the rate of new-build in these new nuclear<br />

markets means there could be challenges, even for existing<br />

companies, related to rapid expansion. There could be<br />

challenges to the ability of some expanding companies<br />

to provide experienced and qualified people to staff their<br />

new units, he said.<br />

In supporting countries with new units beginning<br />

operation, WANO is working more closely with the<br />

International Atomic Energy Agency (IAEA). One of the<br />

IAEA’s tasks is to help emerging nuclear countries develop<br />

the infrastructure and capability they need to have nuclear<br />

power as part of their energy mix.<br />

Mr Prozesky said WANO, whose members operate some<br />

440 nuclear reactor units in more than 30 countries, has<br />

developed a strong relationship between its London office<br />

and IAEA headquarters in Vienna to ensure that experience<br />

is regularly shared. He said: “The IAEA gets involved with<br />

new entrants a lot earlier than we do. They are focusing on<br />

member countries and setting up infrastructure, while<br />

WANO needs to engage when new-build contracts get<br />

signed. The aim is now to have WANO involved as early as<br />

possible.”<br />

WANO is developing training modules and support<br />

missions for new nuclear countries. Modules cover the<br />

period from the start of contractual work to commercial<br />

operation, and aim to help utilities and companies during<br />

the construction and commissioning phases. Early engagement<br />

with the IAEA is part of WANO’s Compass plan, which<br />

was conceived in 2015 and updated at this year’s biennial<br />

general meeting, in Gyeongju, South Korea.<br />

The revised schedule for Compass, which also includes<br />

plans to make WANO more effective in areas such as<br />

life-extensions and decommissioning of plants, is 2<strong>02</strong>2.<br />

The original Compass ran until 2019, but that target has<br />

now been revised, Mr Prozesky said.<br />

Earlier this year the IAEA and WANO agreed to increase<br />

their cooperation to strengthen operational safety and to<br />

support countries that are planning or considering<br />

launching nuclear power programmes. They said they<br />

can maximise safety benefits, increase efficiency and<br />

avoid conflicting advice by increasing cooperation on<br />

safety peer review services.<br />

Increasing the efficiency of the reviews will be particularly<br />

important in anticipation of the increasing number of<br />

nuclear facilities worldwide in coming decades, WANO<br />

chairman Jacques Regaldo said at the time. “By 2030, half<br />

of the nuclear power reactors will be based in Asia, and we<br />

will have many newcomers to nuclear power,” he said.<br />

“There is real value for WANO to work together with the<br />

IAEA and others to help maximise the safety and reliability<br />

of nuclear power plants.”<br />

In an August 2017 report the IAEA said it foresees a<br />

significant decline in nuclear expansion in North America<br />

and in northern, western and southern Europe, with only<br />

slight increases in Africa and western Asia.<br />

But significant growth is projected in central and<br />

eastern Asia, where nuclear power capacity is expected to<br />

undergo an increase of 43 % by 2050.<br />

WANO has been discussing plans for a new regional<br />

centre in Asia to meet demand for expertise and missions<br />

from companies operating new units. The organisation<br />

already has regional centres in Atlanta, Moscow, Paris and<br />

Tokyo, with a head office in London.<br />

WANO has decided to look into the possibility of setting<br />

up a new regional centre, starting with a proposal to open<br />

a branch of the London office in Shanghai. The main aim of<br />

this office will be to develop local expertise.<br />

The second phase of opening a new regional centre<br />

would then include converting the branch office into a<br />

support centre which would provide support services to<br />

other regions. These initial preparations depend on a vote<br />

by WANO members, probably in <strong>2018</strong>. When the support<br />

centre is operating as it should, it would become a fully<br />

operational regional centre.<br />

Mr Prozesky said WANO is holding discussions with<br />

its Chinese members about “the sharing of financial<br />

responsibility” for funding the Shanghai office through the<br />

first two phases.<br />

At its biennial general meeting, WANO discussed the<br />

implications of financial and market pressures. Corporate<br />

organisations “have huge responsibilities” to ensure that<br />

operating nuclear plants are carefully managed and<br />

adequately resourced in these difficult times, Mr Prozesky<br />

said.<br />

The organisation also started a discussion on how it<br />

should be supporting units when they approach the end of<br />

their designed lifetime.<br />

Members spoke about the need to increase cooperation<br />

amongst like-minded organisations such as the IAEA and<br />

the Paris-based Nuclear Energy Agency.<br />

WANO recently announced the signing of a cooperation<br />

agreement with the International Youth Nuclear Congress<br />

(IYNC), recognition of the fact that WANO needs to find<br />

ways to transfer knowledge from people who have been in<br />

the industry for the past 40 years to those who are entering<br />

it today.<br />

Mr Prozesky said it was “quite sobering” to talk to young<br />

operators in control rooms today and find that some of<br />

them weren’t born when the Chernobyl accident happened<br />

in 1986. He said: “It is essential that transfer all the<br />

accumulated knowledge and the industry’s experience to<br />

Inside Nuclear with NucNet<br />

WANO to Increase Focus on New Nuclear as Industry’s Centre of Gravity Shifts Towards Asia ı NucNet


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

the new generation. We must find out how to make the<br />

industry attractive to the younger generation.”<br />

Mr Prozesky said members have asked WANO “to do a<br />

little bit more” on providing support as opposed to just<br />

carrying out assessments of their businesses. He said<br />

another point in the updated Compass document is<br />

associated with putting more energy into leadership<br />

development. “We find in our assessment process across<br />

the world, when looking at corporate organisations and<br />

power plants, that there is a need for WANO to develop<br />

products and services aimed at creating leaders for the<br />

nuclear industry.<br />

“So, we will be putting some energy into that over the<br />

next four years. Particularly again, the focus and emphasis<br />

will be on new entrants and new units, but there is an<br />

overall need for developing leadership in the rest of the<br />

world as well.”<br />

Author<br />

NucNet<br />

The Independent Global Nuclear News Agency<br />

Editor responsible for this story: Kamen Kraev<br />

Avenue des Arts 56<br />

1000 Brussels, Belgium<br />

www.nucnet.org<br />

DATF EDITORIAL NOTES<br />

79<br />

Notes<br />

New Explanatory Video: Multi-Talented Nuclear Technology<br />

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Our explanatory video presents various applications and<br />

shows by the examples of medicine and industry, why nuclear<br />

technology not only enriches our life but also can make it safer,<br />

healthier and longer.<br />

You get brief informations on these and more topics in this<br />

explanatory video from DAtF (in German).<br />

3 The complete video can be watched at www.kernenergie.de<br />

or at the DAtF YouTube channel.<br />

3 A more comprehensive brochure of DAtF on nuclear technology<br />

and additional information (all in German) are available on<br />

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For further details<br />

please contact:<br />

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E-mail: presse@<br />

kernenergie.de<br />

www.kernenergie.de<br />

DAtF Notes


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

80<br />

CALENDAR<br />

Calendar<br />

<strong>2018</strong><br />

05.<strong>02</strong>.-07.<strong>02</strong>.<strong>2018</strong><br />

Components and Structures under Severe<br />

Accident Loading Cossal (COSSAL).<br />

Cologne, Germany. OECD/NEA, GRS,<br />

www.grs.de, www.oecd-nea-org<br />

07.<strong>02</strong>.-08.<strong>02</strong>.<strong>2018</strong><br />

8. Symposium Stilllegung und Abbau<br />

kerntechnischer Anlagen. Hanover, Germany.<br />

TÜV Nord, www.tuev.nord.de<br />

26.<strong>02</strong>.-01.03.<strong>2018</strong><br />

Nuclear and Emerging Technologies for Space<br />

<strong>2018</strong>. Las Vegas, NV, USA. American Nuclear Society<br />

(ANS), www.ans.org<br />

01.03.<strong>2018</strong><br />

7. Fachgespräch Endlagerbergbau. Essen,<br />

Germany, DMT, GNS, www.dmt-goup.com<br />

04.03.-09.03.<strong>2018</strong><br />

82. Jahrestagung der DPG. Erlangen, Germany,<br />

Deutsche Physikalische Gesellschaft (DPG),<br />

www.dpg-physik.de<br />

11.03.-17.03.<strong>2018</strong><br />

International Youth Nuclear Congress (IYNC).<br />

Bariloche, Argentina, IYNC and WiN Global,<br />

www.iync.org/category/iync<strong>2018</strong>/<br />

26.03.-27.03.<strong>2018</strong><br />

Fusion energy using tokamaks: can development<br />

be accelerated? London, United Kingdom,<br />

The Royal Society, royalsociety.org<br />

08.04.-11.04.<strong>2018</strong><br />

International Congress on Advances in Nuclear<br />

Power Plants – ICAPP 18. Charlotte, NC, USA,<br />

American Nuclear Society (ANS), www.ans.org<br />

08.04.-13.04.<strong>2018</strong><br />

11 th International Conference on Methods and<br />

Applications of Radioanalytical Chemistry –<br />

MARC XI. Kailua-Kona, HI, USA, American Nuclear<br />

Society (ANS), www.ans.org<br />

17.04.-19.04.<strong>2018</strong><br />

World Nuclear Fuel Cycle <strong>2018</strong>. Madrid, Spain,<br />

World Nuclear Association (WNA),<br />

www.world-nuclear.org<br />

18.04.-19.04.<strong>2018</strong><br />

9. Symposium zur Endlagerung radioaktiver Abfälle.<br />

Vorbereitung auf KONRAD – Wege zum G2-<br />

Gebinde. Hanover, Germany, TÜV NORD Akademie,<br />

www.tuev-nord.de/tk-era<br />

22.04.-26.04.<strong>2018</strong><br />

Reactor Physics Paving the Way Towards More<br />

Efficient Systems – PHYSOR <strong>2018</strong>. Cancun, Mexico,<br />

www.physor<strong>2018</strong>.mx<br />

08.05.-10.05.<strong>2018</strong><br />

29 th Conference of the Nuclear Societies in Israel.<br />

Herzliya, Israel. Israel Nuclear Society and Israel<br />

Society for Radiation Protection, ins-conference.com<br />

13.05.-19.05.<strong>2018</strong><br />

BEPU-<strong>2018</strong> – ANS International Conference on<br />

Best-Estimate Plus Uncertainties Methods. Lucca,<br />

Italy, NINE – Nuclear and INdustrial Engineering S.r.l.,<br />

ANS, IAEA, NEA, www.nineeng.com/bepu/<br />

13.05.-18.05.<strong>2018</strong><br />

RadChem <strong>2018</strong> – 18 th Radiochemical Conference.<br />

Marianske Lazne, Czech Republic,<br />

www.radchem.cz<br />

14.05.-16.05.<strong>2018</strong><br />

ATOMEXPO <strong>2018</strong>. Sochi, Russia,<br />

atomexpo.ru<br />

15.05.-17.05.<strong>2018</strong><br />

11 th International Conference on the Transport,<br />

Storage, and Disposal of Radioactive Materials.<br />

London, United Kingdom, Nuclear Institute,<br />

www.nuclearinst.com<br />

20.05.-23.05.<strong>2018</strong><br />

5 th Asian and Oceanic IRPA Regional Congress on<br />

Radiation Protection – AOCRP5. Melbourne,<br />

Australia, Australian Radiation Protection Society<br />

(ARPS) and International Radiation Protection<br />

Association (IRPA), www.aocrp-5.org<br />

29.05.-30.05.<strong>2018</strong><br />

49 th Annual Meeting on Nuclear Technology<br />

AMNT <strong>2018</strong> | 49. Jahrestagung Kerntechnik.<br />

Berlin, Germany, DAtF and KTG,<br />

www.nucleartech-meeting.com<br />

03.06.-07.06.<strong>2018</strong><br />

38 th CNS Annual Conference and 42 nd CNS-CNA<br />

Student Conference. Saskotoon, SK, Canada,<br />

Candian Nuclear Society CNS, www.cns-snc.ca<br />

03.06.-06.06.<strong>2018</strong><br />

HND<strong>2018</strong> 12 th International Conference of the<br />

Croatian Nuclear Society. Zadar, Croatia, Croatian<br />

Nuclear Society, www.nuklearno-drustvo.hr<br />

04.06.-07.06.<strong>2018</strong><br />

10 th Symposium on CBRNE Threats. Rovaniemi,<br />

Finland, Finnish Nuclear Society, ats-fns.fi<br />

04.06.-08.06.<strong>2018</strong><br />

5 th European IRPA Congress – Encouraging<br />

Sustainability in Radiation Protection.<br />

The Hague, The Netherlands, Dutch Society for<br />

Radiation Protection (NVS), local organiser,<br />

irpa<strong>2018</strong>europe.com<br />

06.06.-08.06.<strong>2018</strong><br />

2 nd Workshop on Safety of Extended Dry Storage<br />

of Spent Nuclear Fuel. Garching near Munich,<br />

German, GRS, www.grs.de<br />

17.06.-21.06.<strong>2018</strong><br />

ANS Annual Meeting “Future of Nuclear in the<br />

Shifting Energy Landscape: Safety, Sustainability,<br />

and Flexibility”. Philadelphia, PA, USA, American<br />

Nuclear Society (ANS), www.ans.org<br />

25.06.-26.06.<strong>2018</strong><br />

index<strong>2018</strong> – International Nuclear Digital<br />

Experience. Paris, France, Société Française<br />

d’Energie Nucléaire,<br />

www.sfen.org, www.sfen-index<strong>2018</strong>.org<br />

27.06.-29.06.<strong>2018</strong><br />

EEM – <strong>2018</strong> 15 th International Conference<br />

on the European Energy Market. Lodz, Poland,<br />

Lodz University of Technology, Institute of Electrical<br />

Power Engineering, Association of Polish Electrical<br />

Engineers (SEP), www.eem18.eu<br />

29.07.-<strong>02</strong>.08.<strong>2018</strong><br />

International Nuclear Physics Conference 2019.<br />

Glasgow, United Kingdom, www.iop.org<br />

05.08.-08.08.<strong>2018</strong><br />

Utility Working Conference and Vendor<br />

Technology Expo. Amelia Island, FL, USA,<br />

American Nuclear Society (ANS), www.ans.org<br />

22.08.-31.08.<strong>2018</strong><br />

Frédéric Joliot/Otto Hahn (FJOH) Summer School<br />

FJOH-<strong>2018</strong> – Maximizing the Benefits of<br />

Experiments for the Simulation, Design and<br />

Analysis of Reactors. Aix-en-Provence, France,<br />

Nuclear Energy Division of Commissariat à l’énergie<br />

atomique et aux énergies alternatives (CEA) and<br />

Karlsruher Institut für Technologie (KIT),<br />

www.fjohss.eu<br />

28.08.-31.08.<strong>2018</strong><br />

TINCE <strong>2018</strong> – Technological Innovations in<br />

Nuclear Civil Engineering. Paris Saclay, France,<br />

Société Française d’Energie Nucléaire,<br />

www.sfen.org, www.sfen-tince<strong>2018</strong>.org<br />

05.09.-07.09.<strong>2018</strong><br />

World Nuclear Association Symposium <strong>2018</strong>.<br />

London, United Kingdom, World Nuclear Association<br />

(WNA), www.world-nuclear.org<br />

09.09.-14.09.<strong>2018</strong><br />

21 st International Conference on Water<br />

Chemistry in Nuclear Reactor Systems.<br />

EPRI – Electric Power Research Institute,<br />

San Francisco, CA, USA, www.epri.com<br />

09.09.-14.09.<strong>2018</strong><br />

Plutonium Futures – The Science <strong>2018</strong>. San Diego,<br />

United States, American Nuclear Society (ANS),<br />

www.ans.org<br />

10.09.-13.09.<strong>2018</strong><br />

Nuclear Energy in New Europe – NENE <strong>2018</strong>.<br />

Portoroz, Slovenia, Nuclear Society of Slovenia,<br />

www.nss.si/nene<strong>2018</strong>/<br />

17.09.-21.09.<strong>2018</strong><br />

62 nd IAEA General Conference. Vienna, Austria.<br />

International Atomic Energy Agency (IAEA),<br />

www.iaea.org<br />

17.09.-20.09.<strong>2018</strong><br />

FONTEVRAUD 9. Avignon, France,<br />

Société Française d’Energie Nucléaire (SFEN),<br />

www.sfen-fontevraud9.org<br />

17.09.-19.09.<strong>2018</strong><br />

4 th International Conference on Physics and<br />

Technology of Reactors and Applications –<br />

PHYTRA4. Marrakech, Morocco, Moroccan<br />

Association for Nuclear Engineering and Reactor<br />

Technology (GMTR), National Center for Energy,<br />

Sciences and Nuclear Techniques (CNESTEN) and<br />

Moroccan Agency for Nuclear and Radiological<br />

Safety and Security (AMSSNuR), phytra4.gmtr.ma<br />

30.09.-04.10.<strong>2018</strong><br />

TopFuel <strong>2018</strong>. Prague, Czwech Republic,<br />

European Nuclear Society (ENS), American Nuclear<br />

Society (ANS). Atomic Energy Society of Japan,<br />

Chinese Nuclear Society and Korean Nuclear Society,<br />

www.euronuclear.org<br />

30.09.-05.10.<strong>2018</strong><br />

Pacific Nuclear Basin Conferences – PBNC <strong>2018</strong>.<br />

San Francisco, CA, USA, American Nuclear Society<br />

(ANS), www.ans.org<br />

<strong>02</strong>.10.-04.10.<strong>2018</strong><br />

7 th EU Nuclear Power Plant Simulation ENPPS<br />

Forum. Birmingham, United Kingdom, Nuclear<br />

Training & Simulation Group, www.enpps.tech<br />

14.10.-18.10.<strong>2018</strong><br />

12 th International Topical Meeting on Nuclear<br />

Reactor Thermal-Hydraulics, Operation and<br />

Safety – NUTHOS-12. Qingdao, China, Elsevier,<br />

www.nuthos-12.org<br />

14.10.-18.10.<strong>2018</strong><br />

NuMat <strong>2018</strong>. Seattle, United States,<br />

www.elsevier.com<br />

16.10.-17.10.<strong>2018</strong><br />

4 th GIF Symposium at the 8 th edition of Atoms for<br />

the Future. Paris, France, www.gen-4.org<br />

22.10.-24.10.<strong>2018</strong><br />

DEM <strong>2018</strong> Dismantling Challenges: Industrial<br />

Reality, Prospects and Feedback Experience. Paris<br />

Saclay, France, Société Française d’Energie Nucléaire,<br />

www.sfen.org, www.sfen-dem<strong>2018</strong>.org<br />

22.10.-26.10.<strong>2018</strong><br />

NUWCEM <strong>2018</strong> Cement-based Materials for<br />

Nuclear Waste. Avignon, France, French<br />

Commission for Atomic and Alternative Energies<br />

and Société Française d’Energie Nucléaire,<br />

www.sfen-nuwcem<strong>2018</strong>.org<br />

24.10.-25.10.<strong>2018</strong><br />

Chemistry in Power Plant. Magdeburg, Germany,<br />

VGB PowerTech e.V., www.vgb.org<br />

11.11.-15.11.<strong>2018</strong><br />

ANS Winter Meeting. Orlando, FL, USA,<br />

American Nuclear Society (ANS), www.ans.org<br />

Calendar


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

Development of High Temperature<br />

Gas Cooled Reactor in China<br />

Wentao Guo and Michael Schorer<br />

1 Introduction of HTGR Recent developments in High Temperature Gas Cooled Reactor (HTGR) attracted<br />

widespread attention. China, Japan, South Africa, USA, Russia and France are all actively initiating the development<br />

work of HTGR. Some developing countries expressed great interest in this type of reactor [1].<br />

| | Fig. 1.<br />

The 10 MWt High Temperature<br />

Gas-cooled Reactor (HTGR)<br />

| | Fig. 2.<br />

The Pebble fuel element<br />

of the HTGR<br />

HTGR is one of the six Generation IV reactors put forward<br />

by Generation IV International Forum (GIF) in 20<strong>02</strong>.<br />

This type of reactor has high outlet temperature. It uses<br />

Helium as coolant and graphite as moderator. The helium<br />

temperature at the reactor core inlet/outlet is 250/750 °C.<br />

Pebble fuel and ceramic reactor core are adopted. At the<br />

center of each poppy seed-size fuel particle is a uranium<br />

kernel. Layers of carbon and silicon carbide contain the<br />

radioactive material [2]. Figure 1 shows the overall<br />

structure of the HTR-10 MW Test Module constructed by<br />

Institute of Nuclear and New Energy Technology, Tsinghua<br />

University (INET). Figure 2 shows the pebble fuel element<br />

structure of HTGR.<br />

The most important feature of modular high temperature<br />

gas cooled reactor is that under any accident conditions,<br />

including large loss of coolant accident (LLOCA),<br />

the reactor can keep in safe state without any human or<br />

machine intervention.<br />

Modular HTGR also has other advantages such as:<br />

1. High generating efficiency: Its efficiency is 25 % higher<br />

than pressurized water reactor (PWR) nuclear power<br />

plants because of the high outlet temperature.<br />

2. 2. Short construction period: 100 MWe HTGR adopts<br />

modular construction approach. Construction period<br />

can be reduced to two years. Compared to PWR power<br />

plants which have 5 to 6 years of construction, the<br />

interest payment during construction is reduced and<br />

the construction investment can be reduced by 20 %.<br />

3. 3. Simple system: The HTGR has passive safety features<br />

which greatly simplify the system. Engineering safety<br />

facilities like emergency core cooling system and full<br />

grade containment don’t need to be installed, which<br />

can reduce the construction investment.<br />

2 The development history of China’s HTR<br />

and its current situation<br />

The HTGR research and development work in China started<br />

in 1970s. By implementing the National High-Technology<br />

Project (863), Tsinghua University designed and<br />

built HTR-10 MW Test Module under the support<br />

of China National Nuclear Corporation (CNNC). It<br />

realized the first power generation on January 7,<br />

2003 [3].<br />

In 2006, Tsinghua University in Beijing, China<br />

Nuclear Engineering Group Corporation (CNEC)<br />

and China Huaneng Group co-financed the<br />

construction of the HTR demonstration project,<br />

after which a complete industrial chain is formed.<br />

In this system, Institute of Nuclear and New Energy<br />

Technology, Tsinghua University is the liability<br />

subject of R&D in charge of technology R&D,<br />

providing design and technical support; CNEC<br />

is the major special project implementation<br />

body, responsible for designing, purchasing and<br />

constructing the demonstration project of<br />

nuclear island and its auxiliary system; Huaneng Shandong<br />

Shidao Bay Nuclear Power CO., LTD. takes charge of the<br />

investment operations of the demonstration project [4].<br />

The High Temperature Reactor-Pebble-bed Modules<br />

(HTR-PM) under construction has two reactors and<br />

one turbine. On December 9, 2012, the construction of<br />

Shandong Rongcheng Shidao Bay HTR demonstration<br />

project started. On April 20, 2015, civil construction of the<br />

basements came to an end and turned to the intensive<br />

equipment installation stage. The key point for construction<br />

was shifted from civil construction to installation<br />

construction. On June the 24 th , after two months of<br />

arduous struggle, the Shidao Bay Nuclear Power Project<br />

completed the pouring task of the reactor building<br />

walls for the first modular High Temperature Gas-cooled<br />

Demonstration Reactor in the world [5]. The reactor<br />

building walls were poured to 41.30 meters, marking<br />

the HTGR project meeting the requirement of heavy<br />

equipment lifting. On June the 27 th , capping of the Shidao<br />

Bay HTGR conventional island is finished [6]. This is<br />

another major project after the pouring task on June 24 th .<br />

On March 3, 2016, the construction of the reactor<br />

pressure vessel (RPV) and metal components inside the<br />

reactor was finished and they were transported to the site.<br />

On September 14, 2016, they finished installing the RPV<br />

for the first and second reactor as well as the internal metal<br />

components of RPV for the first reactor. The cylindrical<br />

vessel, 25 meters high and weighing 610 tons, is the<br />

biggest, heaviest and most complicated pressure vessel for<br />

a nuclear reactor, according to a statement from Huaneng<br />

Shandong Shidao Bay Nuclear Power Co. (HSNPC), the<br />

plant’s builder and operator. On October 14, 2016, the<br />

demonstration project finished all the tests of inverse<br />

power transmission successfully. On December 29, 2016,<br />

the main control room in Shidao Bay nuclear power plant<br />

is ready to be used. On January 21, 2017, the installation of<br />

the reactor core vessel was finished. The reactor core vessel<br />

is the key component of the metal structures inside the<br />

81<br />

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<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

ENERGY POLICY, ECONOMY AND LAW 82<br />

reactor core. It is used to support the reactor core and<br />

locate the reactor core components. On June 8, 2017, the<br />

installation of the ceramic components inside the second<br />

reactor core was finished, which means half of the<br />

installation progress of the main facilities in the nuclear<br />

island has been done. Before August 11, 2017, the fuel<br />

production line has produced 250,000 pebbles, which met<br />

the requirement of connecting to the grid for HTR-PM.<br />

The project is planned to be completed and put into operation<br />

at the end of 2017/beginning of <strong>2018</strong>, but probably<br />

it will be delayed (Figure 3). The design lifetime of<br />

HTR-PM is 40 years.<br />

| | Fig. 3.<br />

The construction of Shidao Bay HTGR conventional island was finished<br />

on June 27, 2015 (photo credits: Shidao Bay NPP).<br />

3 Safety features of HTGR<br />

One of the most important safety issues for nuclear power<br />

plant is decay heat removal. In the Three Mile Island and<br />

Fukushima Daiichi nuclear accidents, the reactor cores are<br />

overheated and melt down due to the failure of decay heat<br />

removal. In Chernobyl accident, the failure of decay heat<br />

removal system caused the resulting sequences after the<br />

initial exploration due to the fission power increment.<br />

So developing a highly reliable emergency core cooling<br />

system with reliable water and electricity supply is very<br />

important for a light water reactor (LWR).<br />

But for HTGR, inherent safety can be achieved based<br />

on three physical ideas: 1. using silicon carbide (SiC),<br />

which has very good heat-resistance, as the fuel cladding;<br />

2. lowering the volumetric power density of the reactor<br />

core significantly; 3. using identical small reactor modules<br />

to replace a large reactor in order to make sure that the<br />

reactor core won’t be heated to the temperature limit [7].<br />

Besides physical ideas, the safety of HTGR can be<br />

protected from three engineering designs:<br />

1. Multiple barriers to prevent the release of<br />

radioactivity<br />

The HTGR has three safety barriers to prevent the release<br />

of radioactivity. The first barrier is the fuel particles coated<br />

with SiC. The maximum temperature of the fuel particles<br />

is designed to be limited to 1,600 °C under any operation<br />

or accident conditions. Less than 1,600 °C, the coat of the<br />

particles can maintain integrated [8]. The second barrier<br />

is the pressure boundary of the primary circuit, which<br />

contains the reactor pressure vessel, the steam generator<br />

pressure vessel and the hot gas duct pressure vessel which<br />

connects the previous two vessels. The likelihood for<br />

these three vessels to have ruptures can be neglected. The<br />

third barrier is the bounding volume, which contains the<br />

primary circuit cabin, Helium purification cabin as well as<br />

fuel loading and unloading cabin. They can prevent the<br />

radioactive gas to be released into the atmosphere.<br />

2 Passive decay heat removal system<br />

The thermal design of HTGR has already considered that<br />

in case of any accidents, the cooling of the reactor core<br />

doesn’t need any active decay heat removal system. The<br />

decay heat in the reactor core can be removed from the<br />

core to the surface cooler outside of the reactor pressure<br />

vessel passively through heat conduction and radiation.<br />

Then the heat can be passed to the atmosphere from the<br />

surface cooler by nature convection. If the primary circuit<br />

lost pressure and the main and the auxiliary decay heat<br />

removal system are out of work, the decay heat can still be<br />

removed from the core to the outside. The reactor core<br />

meltdown can be avoided. Under accident conditions,<br />

because the decay heat cannot be removed by the main<br />

decay heat removal system, the temperature of the pebbles<br />

will be increased. In order to make sure the maximum<br />

temperature of the pebbles will not exceed 1,600 °C, some<br />

restrictions to the power density and geometry of the<br />

reactor core are necessary. That’s the reason why the<br />

capacity of the HTGR is usually small.<br />

3 Negative temperature coefficient has good reactivity<br />

compensation<br />

The reactor has a relatively high negative temperature<br />

coefficient for the fuel and moderator and if it is under<br />

normal condition, the margin between the maximum<br />

temperature of the pebbles and its limit is large. The<br />

negative temperature coefficient can give a good reactivity<br />

compensation. When a positive reactivity is introduced<br />

into the reactor, it can be automatically shut down thanks<br />

to the reactivity compensation from the negative temperature<br />

coefficient [9].<br />

The long term operation of HTR-10 and different<br />

safety experiments have proved the inherent safety of<br />

HTGR, which improved the public acceptance of nuclear<br />

reactors.<br />

4 Fuel technology<br />

In 2005, INET built a prototyping fuel-production facility<br />

with a capacity of 100,000 fuel elements per year. In order<br />

to solidify the fabrication level, INET started to construct<br />

HTGR fuel-production factory in Baotou, Northern China<br />

in 2013. The fuel-production equipment was installed in<br />

2014. In 2015, they started the commissioning and trial<br />

production. Some experiments have been done in Petten,<br />

the Netherlands. The irradiation test of five fuel spheres of<br />

the HTR-PM started in October 2012 in the high flux<br />

reactor (HFR) and finished on December 30, 2014. The<br />

fuel sphere quality, which is one of the key technologies in<br />

HTR-PM project, has been proved to meet the requirements<br />

[7].<br />

On August 15, 2016, the construction of the fuel<br />

production line in Baotou was finished and the fuel pebble<br />

production started. By July 17, 2017, the fuel production<br />

line has already produced 200,000 pebbles. It means<br />

that the fuel production of HTGR has shifted from trial<br />

production to industrial production. It also means that the<br />

fuel production technology of HTGR in China is leading<br />

the world, which has great significance for achieving<br />

commercialization and export of HTGR [10].<br />

When a fuel element is discharged from the bottom<br />

of the RPV to the fuel handling system, its burn-up is<br />

measured immediately. If its burn-up does not reach the<br />

design burn-up limit, it will be recharged into the reactor<br />

Energy Policy, Economy and Law<br />

Development of High Temperature Gas Cooled Reactor in China ı Wentao Guo and Michael Schorer


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

core from the top of the RPV. Otherwise it will be identified<br />

as a spent fuel and sent to the spent fuel storage system. In<br />

the spent fuel storage system, spent fuels are put into a<br />

storage canister. Each storage canister contains 40,000<br />

spent fuels. After a storage canister is full with spent<br />

fuels, it is sealed and moved to the ventilated storage well.<br />

Each storage well contains five vertically placed storage<br />

canisters. Spent fuels after ten years of storage will be<br />

moved from the nuclear island to a large intermediate<br />

storage building on the site and stored there during the<br />

rest service time of the plant. As for reprocessing, it is<br />

technically feasible and similar to the technology used in<br />

PWR. At present, China is still developing this reprocessing<br />

technology and tends to apply it in the future.<br />

5 Future expectations of HTGR in China<br />

The HTGR industrialization has shifted from research<br />

toward commercial applications. CNEC announced that<br />

the feasibility study report of the 600 MWe commercial<br />

high temperature reactor project in Ruijin, Jiangxi province<br />

has passed the experts auditing and promises to be the<br />

first commercial Generation IV nuclear power plant in the<br />

world. At present, China has mastered all the technology of<br />

HTGR systematically and takes the lead in the world.<br />

The home manufacture can be realized for 95 % of the<br />

equipment.<br />

Next step, CNEC and Jiangxi Province will combine<br />

together and submit the project proposals to the National<br />

Development and Reform Commission (NDRC), applying to<br />

list the project into National Nuclear Long-and-medium<br />

Term Development Planning. After having the permit, the<br />

feasibility study of the project will be carried out. Land<br />

requisition, “Five-outlet-one Dish” 1<br />

and construction of<br />

auxiliary facilities will be carried on at the same time. After<br />

getting the approval from NDRC and obtaining building<br />

permits from National Nuclear Safety Administration<br />

( NNSA), the commencement of work for the two units in<br />

the first-stage project was planned in 2017 and they would<br />

be combined to the grid around 2<strong>02</strong>1. But due to some<br />

reasons this project is delayed and hasn’t been started yet.<br />

6 HTGR cooperation between China and<br />

other countries<br />

By the way of multi-module combination, the installed<br />

capacity of HTGR nuclear power units can be 200 MWe,<br />

400 MWe, 600 MWe, 800 MWe and 1000 MWe, which can<br />

be operated with flexibility to suit the market and meet<br />

the need of different power grid. It is suitable for being<br />

constructed close to load centers as well as in countries<br />

and regions with small or middle power grids.<br />

Many countries in Southeast Asia, Middle East and<br />

Europe, including some potential users in China, express a<br />

keen interest in the application of HTGR in nuclear electric<br />

power generation, sea water desalination, petrochemical<br />

industry and coal chemical industry. The related business<br />

cooperation is under way.<br />

At present, CNEC starts working on HTGR preliminary<br />

work in Jiangxi, Hunan, Guangdong, Fujian, Shandong,<br />

Hubei and Zhejiang province successively. Meanwhile,<br />

CNEC signs the memorandum of understanding (MOU) on<br />

cooperation with Dubai Nuclear Energy Committee and<br />

provides King Abdulaziz City for Science and Technology<br />

(KACST) with the design scheme of HTGR sea water desalination.<br />

They have also reached a consensus on signing the<br />

memorandum of understanding on cooperation with Saudi<br />

Energy City. On April 21, 2015, they signed the MOU<br />

with South African Nuclear Energy Corporation (NECSA).<br />

CNEC is jointly with other organization concerned to provide<br />

nuclear fuels, spent fuel reclamation, nuclear power<br />

plant operation, technical support, personnel training and<br />

other integration services to the international market.<br />

7 Conclusions<br />

The Generation IV nuclear power system is an advanced<br />

system which has a major revolution in economy, safety,<br />

waste treatment and nuclear nonproliferation. HTGR is<br />

considered to be the most possibly actualized and the most<br />

promising advanced reactor type in the near future by the<br />

international nuclear community [9].<br />

Under the support of the National High-Technology<br />

Project, Institute of Nuclear and New Energy Technology,<br />

Tsinghua University constructed the HTR-10 MW Test<br />

Module successfully, and achieved joining the national<br />

power grid with full power. Long-term operation and<br />

safety tests verified the intrinsic safety of HTGR and<br />

proved the technical feasibility of HTGR. The success of<br />

HTR-10 MW Test Module construction and operation<br />

marks that China has made a breakthrough in the R&D of<br />

HTGR. China has been included among those advanced<br />

countries in the development of HTGR technology. The<br />

construction of the Shidao Bay HTR-PM demonstration<br />

project is close to an end. Hopefully it will start operation<br />

in the near future. At that time, it will be the world’s first<br />

modular HTGR commercial demonstration power plant.<br />

In early 2006, large pressurized water reactor and<br />

HTGR were included in the 16 major scientific and<br />

technological projects by “China’s national policy for<br />

medium and long-term scientific development” in which<br />

they are striving to make breakthroughs in 15 years.<br />

Actualizing the major scientific and technological project<br />

of HTGR marks that the HTGR technology in which China<br />

has self-owned intellectual property takes a crucial step<br />

towards industrialization.<br />

References<br />

[1] Zongxin, Wu: The development of high temperature gas-cooled<br />

reactor in China. Nuclear Power Engineering 21.1 (2000): 39-43.<br />

[2] http://baike.baidu.com/<br />

[3] http://military.china.com/news/568/20150421/19562626.html<br />

[4] http://digitalpaper.stdaily.com/http_www.kjrb.com/kjrb/<br />

html/2014-11/01/content_282325.htm?div=-1<br />

[5] http://www.cet.com.cn/nypd/hn/1576726.shtml<br />

[6] http://paper.people.com.cn/zgnyb/html/2015-07/06/<br />

content_1585012.htm<br />

[7] Zhang, Zuoyi, et al.: The Shandong Shidao Bay 200 MW e High-<br />

Temperature Gas-Cooled Reactor Pebble-Bed Module (HTR-PM)<br />

Demonstration Power Plant: An Engineering and Technological<br />

Innovation. Engineering 2.1 (2016): 112-118.<br />

[8] Tang, Chunhe, et al.: Research and development of fuel element<br />

for Chinese 10 MW high temperature gas-cooled reactor. Journal<br />

of Nuclear Science and Technology 37.9 (2000): 8<strong>02</strong>-806.<br />

[9] Fu Xiaoming, Wangjie, October 2006. Summary of HTGR<br />

Development in China. Modern Electric Power.<br />

[10] http://energy.people.com.cn/n1/2017/0718/<br />

c71661-29412747.html<br />

Authors<br />

Wentao Guo<br />

Paul Scherrer Institute<br />

Department of Nuclear Energy and Safety<br />

5232 Villigen PSI, Switzerland<br />

Michael Schorer<br />

Swiss Nuclear Forum<br />

4600 Olten, Switzerland<br />

1) Five-outlet-one Dish:<br />

In order to construct<br />

rationally and<br />

orderly, some firstphase<br />

preparations<br />

need to be made,<br />

such as electrifying,<br />

communication,<br />

road access, water<br />

access, gas access<br />

and land smoothing.<br />

ENERGY POLICY, ECONOMY AND LAW 83<br />

Energy Policy, Economy and Law<br />

Development of High Temperature Gas Cooled Reactor in China ı Wentao Guo and Michael Schorer


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

Die Haftung nach § 26 AtG – ein Mauerblümchen?<br />

84<br />

SPOTLIGHT ON NUCLEAR LAW<br />

Christian Raetzke<br />

Die Haftung für Schäden aus Radioaktivität kann sich nach deutschem Recht aus drei Quellen ergeben. In der<br />

öffentlichen und juristischen Diskussion ist fast immer nur von der Haftung nach dem Pariser Übereinkommen (PÜ) die<br />

Rede. Das PÜ gilt in Deutschland unmittelbar (siehe auch § 25 AtG – Atomgesetz). Es regelt aber nicht den gesamten<br />

Bereich der Atomhaftung, sondern – grob gesagt – nur die Haftung im Rahmen der Kernenergie; für diesen Bereich<br />

mit „besonderem Gefährdungspotential“ wurde ein internationaler Regelungsbedarf gesehen. Das PÜ gilt für<br />

Kernkraftwerke, im „Front end“ für Anreicherungsanlagen und Brennelementfabriken und im „Back end“ für Aktivitäten<br />

rund um die Abfälle aus Kernkraftwerken, jeweils einschließlich der entsprechenden Beförderungsvorgänge.<br />

Als zweite Rechtsgrundlage regelt § 25a AtG die Haftung<br />

für Reaktorschiffe. Mit der Ausmusterung der Otto Hahn<br />

ist diese Norm aber vor langer Zeit in der Versenkung<br />

verschwunden.<br />

Und dann gibt es schließlich den § 26 AtG. Juristisch ist<br />

die Norm als sog. Auffangtatbestand gestaltet. Sie erfasst<br />

alle Schäden „durch die Wirkung eines Kernspaltungsvorgangs<br />

oder der Strahlen eines radioaktiven Stoffes oder<br />

durch die von einer Anlage zur Erzeugung ionisierender<br />

Strahlen ausgehende Wirkung ionisierender Strahlen“,<br />

die nicht in den Anwendungsbereich des PÜ oder des<br />

§ 25a AtG fallen. Aus dieser Negativdefinition und<br />

gleichsam Subtraktion ergibt sich, dass § 26 vor allem auf<br />

Anlagen und Tätigkeiten außerhalb der Kernenergie (und<br />

außer Reaktorschiffen) Anwendung findet, also hauptsächlich<br />

auf den Umgang mit Radioaktivität im Bereich<br />

der Medizin, Industrie (z. B. Prüfstrahler) und Forschung.<br />

Unter die Haftung nach § 26 fallen aber auch solche<br />

Bereiche der Kernindustrie, die aufgrund ihres geringen<br />

Schadenspotentials vom PÜ ausgeschlossen werden,<br />

insbesondere Aktivitäten rund um Natururan und abgereichertes<br />

Uran. Schließlich ordnet § 26 Abs. 2 AtG eine<br />

entsprechende Geltung für die Kernfusion an.<br />

Die Haftung nach § 26 AtG trifft den Besitzer<br />

radio aktiver Stoffe oder von Anlagen zur Erzeugung<br />

ionisierender Strahlen, weswegen man hier von Besitzerhaftung<br />

spricht (manchmal wird auch der Begriff<br />

Isotopenhaftung verwendet, was aber ungenau ist, da es<br />

eben nicht nur um radioaktive Stoffe geht). Im Falle der<br />

Beförderung radioaktiver Stoffe haftet nach Abs. 6 der<br />

Absender.<br />

Dass § 26 AtG für Aktivitäten gilt, die das PÜ gleichsam<br />

„übrig lässt“ und die mit einem geringeren Gefahrenpotential<br />

assoziiert werden, schmälert keinesfalls die<br />

Bedeutung der Norm. Denn zum einen dürften diese Fälle<br />

des Umgangs mit Radioaktivität zahlenmäßig diejenigen,<br />

die sich aus der Nutzung der Kernenergie ergeben, weit<br />

übersteigen; man denke nur an die vielen Transporte von<br />

Strahlenquellen für Medizin und Industrie, die jeden Tag<br />

stattfinden. Zum anderen können sich auch aus diesen<br />

Anlagen und Tätigkeiten im ungünstigsten Fall zwar kaum<br />

nationale Katastrophen, aber doch erhebliche Schäden<br />

bis hin zum Tod von Personen oder zu komplizierten<br />

Kontaminationen ergeben.<br />

In der Frage, ob die Haftung nach § 26 AtG eine<br />

Verschuldenshaftung wie die allgemeine Haftung des<br />

Bürgerlichen Gesetzbuches (setzt Vorsatz oder Fahrlässigkeit<br />

voraus) oder eine verschuldensunabhängige<br />

Gefährdungshaftung (wie im PÜ) sein sollte, hat der<br />

Gesetzgeber eine mittlere Lösung gewählt, die sog. modifizierte<br />

Gefährdungshaftung. Im Grundsatz ist es eine<br />

Gefährdungshaftung: der Geschädigte muss im Prozess<br />

nicht behaupten und beweisen, dass den Besitzer/ Absender<br />

ein Verschulden trifft. Vielmehr ist es am Besitzer/<br />

Absender, einen Entlastungsbeweis zu führen, wenn er<br />

kann; immerhin hat er – im Gegensatz zur reinen Ge fährdungs<br />

haftung – diese Option. § 26 Abs. 1 Satz 2 AtG gibt<br />

hierfür allerdings qualifizierte (erschwerte) Bedingungen<br />

vor; fehlendes Verschulden reicht nicht, es müssen weitere<br />

Umstände wie etwa die nachweisbare „Anwendung jeder<br />

nach den Umständen gebotenen Sorgfalt“ hinzukommen.<br />

Das ist eine hohe Hürde.<br />

Ein zweiter interessanter Aspekt betrifft die Frage<br />

einer möglichen Kanalisierung. Im PÜ ist die Haftung<br />

bekanntlich ausschließlich auf den Inhaber (Betreiber)<br />

einer Kernanlage konzentriert. Zulieferer, Dienstleister<br />

etc. sind freigestellt; Anspruchsgrundlagen außerhalb des<br />

PÜ werden ausgeschlossen. Für den Bereich des § 26 AtG<br />

hat der Gesetzgeber diese Lösung nicht übernommen.<br />

Dem Geschädigten stehen also neben § 26 AtG auch alle<br />

anderen Anspruchsgrundlagen des Haftungsrechts zur<br />

Verfügung und er kann, wenn die Voraussetzungen<br />

vorliegen, auch andere Beteiligte als den Besitzer/<br />

Absender in Anspruch nehmen. Als „Ausgleich“ für diese<br />

anderen Beteiligten ist in § 4 der Atomrechtlichen<br />

Deckungsvorsorge-Verordnung (AtDeckV) geregelt, dass<br />

der Besitzer/Absender sie in bestimmtem Umfang in seine<br />

eigene Haftpflichtversicherung einbeziehen muss (sog.<br />

wirtschaftliche Kanalisierung).<br />

Damit ist auch schon ein dritter Aspekt angesprochen:<br />

für Tätigkeiten im Bereich des § 26 AtG, die einer<br />

Genehmigung bedürfen, muss im Genehmigungs verfahren<br />

eine Deckungsvorsorge (§ 13 AtG) nachgewiesen werden,<br />

also in der Regel eine Haftpflichtversicherung. Der Betrag<br />

wird auf der Grundlage der AtDeckV im Genehmigungsverfahren<br />

festgesetzt. Die Haftung selber ist unbegrenzt;<br />

übersteigt ein Schaden also den Betrag der Deckungsvorsorge,<br />

muss der Haftende sein Vermögen einsetzen.<br />

§ 26 trifft schließlich einige Sonderregelungen für die<br />

Anwendung von radioaktiven Stoffen oder ionisierender<br />

Strahlen am Menschen in der medizinischen Forschung<br />

(da wird die Haftung verschärft) oder bei der Ausübung<br />

der Heilkunde (dort gilt unter bestimmten Voraussetzungen<br />

statt § 26 die normale Arzthaftung).<br />

Soweit ersichtlich, gab es bisher keine Schadensfälle<br />

im Bereich des § 26, die Anlass zu einschlägiger Rechtsprechung<br />

geboten hätten; das soll auch möglichst<br />

so bleiben. Angesichts des Kernenergieausstiegs, der<br />

juristischen Aufwertung des Strahlenschutzes durch<br />

das neue Strahlenschutzgesetz und der zunehmenden<br />

Bedeutung der Fusionsforschung wird § 26 AtG aber<br />

möglicherweise dennoch etwas aus dem Schatten<br />

des PÜ heraustreten und vielleicht sein unverdientes<br />

„ Mauerblümchendasein“ abstreifen.<br />

Author<br />

Rechtsanwalt Dr. Christian Raetzke<br />

CONLAR Consulting on Nuclear Law and Regulation<br />

Beethovenstr. 19<br />

04107 Leipzig, Germany<br />

Spotlight on Nuclear Law<br />

The Liability According to § 26 of the German Atomic Energy Act – A Wallflower? ı Christian Raetzke


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

Investigation of Conditions Inside the<br />

Reactor Building Annulus of a PWR<br />

Plant of KONVOI Type in Case of Severe<br />

Accidents with Increased Containment<br />

Leakages<br />

Ivan Bakalov and Martin Sonnenkalb<br />

1 Introduction and analysis method The severe accident at Fukushima Daiichi NPP resulted in<br />

severe core damage and significant releases of hydrogen and radioactive materials from primary containment boundary<br />

into or through the reactor buildings of three out of the six reactors (units 1 to 3). Based on analyses of the accident<br />

progression it was realized that accidentally increased leaks from the inertized containment contributed to the<br />

radionuclide and hydrogen release into the reactor building, thus leading to hydrogen explosions, severely damaging<br />

the reactor building constructions.<br />

The Fukushima Daiichi accident triggered<br />

worldwide stress tests and<br />

re-assessments of the NPP plant<br />

safety. In Germany the process<br />

resulted in an improvement and<br />

extension of the existing severe accident<br />

management (SAM) concept<br />

by both additional preventive and<br />

mitigative measures. The main improvements<br />

in the mitigative domain<br />

is a new concept of severe accident<br />

management guidelines (SAMG) with<br />

strategies and procedures intended to<br />

be used by the plant crisis team for<br />

mitigation of the consequences of<br />

severe accidents. The SAMG concept<br />

follows relevant recommendations<br />

of the German Reactor Safety Commission<br />

RSK [1].<br />

Analyses of the hydrogen as well<br />

as aerosol and noble gas behaviour<br />

in case of increased containment<br />

leakages into the reactor building<br />

annulus of a German PWR KONVOI<br />

reference plant under severe accident<br />

conditions have been performed using<br />

the GRS lumped parameter code<br />

COCOSYS. The investigation carriedout<br />

focusses on the assessment of the<br />

efficiency of newly developed SAM<br />

measures as described in the new<br />

SAMG handbook or some measures<br />

proposed in addition for a PWR<br />

reference plant of KONVOI type. The<br />

assessed strategies are related to the<br />

mitigation of challenging conditions<br />

inside the reactor building (RB)<br />

annulus due to design based and<br />

increased containment leakages<br />

during severe accidents.<br />

The analyses are based on previous<br />

GRS investigations of the hydrogen<br />

mitigation concept with passive autocatalytic<br />

recombiners (PAR) inside<br />

the PWR KONVOI containment [2] as<br />

well as the reassessment of the effectiveness<br />

of the filtered containment<br />

venting concept of PWR KONVOI [3].<br />

The main findings contribute to<br />

further improvement of the planned<br />

mitigative SAM measures in case of<br />

enhanced containment leakages into<br />

the reactor building annulus under<br />

severe accident conditions.<br />

1.1 COCOSYS plant model<br />

The COCOSYS nodalisation scheme<br />

of the PWR KONVOI plant with focus<br />

on the RB annulus is presented in<br />

Figure 1. The nodalisation of the<br />

containment and the RB annulus is<br />

developed in such a way that thermal<br />

and gas stratification processes<br />

expected under accident conditions,<br />

local and global convection flows<br />

between the compartments, and longterm<br />

convection processes inside<br />

the containment could be simulated<br />

appropriately. Therefore, a refined<br />

subdivision of the containment compartments<br />

and RB annulus rooms and<br />

free space was chosen. The model<br />

considers all relevant gaseous and<br />

liquid flows through different compartment<br />

connections such as free<br />

openings, fire protection doors, burst<br />

membranes, drainages, etc. For the<br />

purpose of heat and mass transfer<br />

modelling inside the containment<br />

and the RB annulus heat structures<br />

representing the walls, floors, ceilings<br />

and metal internals are introduced<br />

into the model. With all these features<br />

the model adequately represents all<br />

relevant design specific features of the<br />

PWR KONVOI reference plant – both<br />

inside the containment as well as the<br />

RB annulus.<br />

The containment has a total free<br />

volume of 70,000 m 3 . It is subdivided<br />

into four areas which can have<br />

different convection flow regimes<br />

depending on the initial event of a<br />

sequence and the break/discharge<br />

location. The first area represents the<br />

containment compartments, in which<br />

the reactor pressure vessel and the<br />

steam generators are located. The<br />

| | Fig. 1.<br />

COCOSYS nodalisation scheme of the RB annulus and location of containment penetrations through the containment steel shell.<br />

85<br />

ENVIRONMENT AND SAFETY<br />

Environment and Safety<br />

Investigation of Conditions Inside the Reactor Building Annulus of a PWR Plant of KONVOI Type in Case of Severe Accidents with Increased Containment Leakages ı Ivan Bakalov and Martin Sonnenkalb


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

ENVIRONMENT AND SAFETY 86<br />

second and third area comprises the<br />

operating containment compartments<br />

and the containment dome. The<br />

fourth area includes all the compartments<br />

outside the missile protection<br />

cylinder, the periphery of the containment.<br />

The volume of the RB annulus is<br />

subdivided into four areas with a total<br />

volume of 50,000 m 3 . The first area is<br />

the annular gap, located above elevation<br />

21.5 m, which has a total volume<br />

of 14,900 m 3 . This area, in turn, is<br />

divided into six axial levels along the<br />

height of the gap. It is connected to<br />

the lower part of the annular gap<br />

( second area) below elevation 21.5 m<br />

and has a free volume of 4,300 m 3 . In<br />

this area vertical fire protection walls<br />

with metal sheets are located, which<br />

do not allow atmospheric flow in<br />

azimuthal direction. The third area<br />

comprises several separate annulus<br />

rooms located on building floors at<br />

elevation 6 m to 21.5 m. The annulus<br />

rooms at elevation 6 m to 9 m are<br />

separated from the annular gap by<br />

ventilation systems. The connections<br />

between these separate rooms are<br />

provided with fire protection doors<br />

and fire protection flaps, which automatically<br />

close, if the room temperature<br />

exceed ~70° C. The fourth area<br />

represents all annulus rooms below<br />

elevation 6 m with a total volume of<br />

23,100 m 3 . Those rooms have only a<br />

negligible atmosphere exchange with<br />

the annular gap above.<br />

Moreover, the model consists of<br />

all relevant plant systems used during<br />

accidents (e.g. the RB annulus exhaust<br />

air system) or operational systems<br />

foreseen as SAM measures in the<br />

SAMG handbook (e.g. the annulus<br />

air supply/suction system and the<br />

annulus air recirculation systems).<br />

The filtered containment venting<br />

system and the hydrogen recombination<br />

system with about 65 PARs<br />

installed inside the containment are<br />

introduced in the input deck as well,<br />

using the modelling capabilities of the<br />

engineered safety features, integrated<br />

in the COCOSYS code.<br />

The COCOSYS model also includes<br />

the containment design leakage of<br />

0.25 vol.-%/d into the RB annulus.<br />

For the base case analyses the design<br />

leakage is assumed to be at the most<br />

unfavorable place in the area of the<br />

cable penetrations at elevation 12 m<br />

(Figure 1 right side), e.g. the leakage<br />

is located opposite to the single<br />

suction point of the RB annulus<br />

exhaust air system, operated in case<br />

of an accident. In addition, leakages<br />

are defined from the environment<br />

through the auxiliary building main<br />

gate into the lower annulus rooms<br />

(leakages represented by red arrows<br />

in Figure 1).<br />

1.2 Selected representative<br />

Severe Accident Scenarios<br />

Two representative and different<br />

severe accident scenarios – the base<br />

cases – have been selected for the<br />

analyses. Some characteristics of the<br />

scenarios are summarized here, the<br />

timing of main events is provided in<br />

Table 1:<br />

• MBL – a medium break LOCA with<br />

a failure of the emergency core<br />

cooling system after the emergency<br />

water supply tank inventory is<br />

empty; core degradation starts<br />

delayed; sequence results in a<br />

maximum water inventory in the<br />

containment sump and a late<br />

filtered containment venting.<br />

• ND* – a transient with a failure of<br />

steam generator feedwater supply;<br />

failure of injection of active<br />

emergency core cooling systems;<br />

primary circuit depressurization<br />

procedure to avoid reactor pressure<br />

vessel failure at high-pressure;<br />

core degradation starts early;<br />

sequence results in a minimum<br />

water inventory in the containment<br />

sump and an earlier containment<br />

venting.<br />

The two representative base cases<br />

were already used in earlier analyses<br />

[2], [3] with respect to the reassessment<br />

of other mitigative SAM measures.<br />

In both cases, no melt relocation<br />

from the reactor cavity into the containment<br />

sump after melt penetration<br />

of the biological shield was assumed,<br />

just water ingress into the cavity and<br />

therefore extended steam production.<br />

As melt relocation into the sump with<br />

cooling of the relocated melt amount<br />

seems to be a realistic scenario leading<br />

to reduced production of combustible<br />

gases, two additional variant calculations<br />

were done with melt relocation<br />

into the containment sump. Furthermore,<br />

a series of COCOSYS variant<br />

calculations were carried out in order<br />

to investigate the influence of the<br />

following specific aspects:<br />

• Operation/failure of the RB annulus<br />

exhaust air system installed for<br />

accident conditions.<br />

• Variation of the size of containment<br />

leakages into the reactor<br />

building annulus: design leakage<br />

(base case) and a 10 times larger<br />

leakage.<br />

• Variation of the containment<br />

leakage location in the area of<br />

containment cable penetrations.<br />

Moreover, the efficiency of different<br />

SAM measures for mitigation of the<br />

consequences in the RB annulus,<br />

documented in the SAMG handbook<br />

of the reference plant, was analysed.<br />

These measures are as follows:<br />

• Use of RB annulus air supply/<br />

suction system – provision of a<br />

controlled ventilation to reduce<br />

the hydrogen concentration in the<br />

annulus.<br />

• Use of RB annulus air recirculation<br />

system – mixing of the annulus<br />

atmosphere and elimination of gas<br />

stratification.<br />

• Use of emergency air filtration<br />

system – extraction of air from the<br />

RB annulus through a filtration<br />

system to reduce the release of<br />

radionuclides into the environment.<br />

The following SAM measure was<br />

additionally investigated as a possible<br />

alternative method for hydrogen<br />

reduction in the annulus. It is related<br />

to a optional recommendation of the<br />

RSK [1].<br />

• Implementation of a small number<br />

of PARs in the RB annulus upper<br />

part to prevent combustible gas<br />

mixtures.<br />

2 Results – Quantification<br />

of the effectiveness of<br />

selected AM measures<br />

Selected results are presented in the<br />

following only for one base case<br />

scenario (MBL) with the operation of<br />

RB annulus exhaust air system used in<br />

case of accidents and for some variant<br />

Scenario<br />

Start of steam/water<br />

leak flow into<br />

containment<br />

Start of<br />

core melting<br />

RPV failure and<br />

melt release<br />

into cavity<br />

Water ingression into<br />

cavity and possible<br />

melt release into sump<br />

Start of filtered<br />

containmentventing<br />

ND* 1.4 hr 3.5 hr 6.5 hr 17.1 hr 66.5 hr<br />

MBL 0.0 hr 5.8 hr 8.9 hr 13.5 hr 82.2 hr<br />

| | Tab. 1.<br />

Timing of characteristic events of severe accident progression of base case scenarios.<br />

Environment and Safety<br />

Investigation of Conditions Inside the Reactor Building Annulus of a PWR Plant of KONVOI Type in Case of Severe Accidents with Increased Containment Leakages ı Ivan Bakalov and Martin Sonnenkalb


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

calculations. Moreover, the results of<br />

the two severe accident scenarios<br />

(MBL and ND*) for the base cases<br />

with increased containment leakages<br />

are compared regarding their effect<br />

on the accident consequences.<br />

2.1 Base case with containment<br />

design leakage<br />

The hydrogen concentration in the RB<br />

annulus is presented in Figure 2 (left<br />

side). In the base case no formation of<br />

combustible gas mixtures (> 4 vol.-%<br />

hydrogen) in the RB annulus is<br />

observed during the calculated time<br />

period, and some fire protection<br />

doors and flaps between the separated<br />

rooms of the annulus close automatically<br />

when the atmosphere<br />

temperature reaches 70 °C limiting<br />

the hydrogen and radionuclide inflow<br />

into these areas (Figure 2 right side).<br />

Due to the operation of the RB annulus<br />

exhaust air system, the hydrogen<br />

concentration remains below 1 vol.-%<br />

and decreases further in the long term<br />

when the containment filtered venting<br />

starts reducing the hydrogen leakage<br />

from the containment. Gas stratification<br />

with slightly different gas<br />

concentrations at different elevations<br />

is formed in the annulus gap due to<br />

the operation of the annulus exhaust<br />

air system.<br />

| | Fig. 2.<br />

H 2 concentration in the RB annulus for base case scenario (MBL) with operation of RB annulus exhaust air system;<br />

RB annular gap (left) and RB annulus rooms (right).<br />

| | Fig. 3.<br />

H 2 concentration in the RB annulus for base case (left) and variant case (right) with a 10 times larger containment leakage,<br />

both cases with operation of RB annulus exhaust air system.<br />

ENVIRONMENT AND SAFETY 87<br />

2.2 Variant calculation with a<br />

10 times larger containment<br />

leakage<br />

As already mentioned, one of the<br />

goals is to investigate the conditions in<br />

the RB annulus in case of increased<br />

containment leakages. For this purpose,<br />

a COCOSYS variant calculation<br />

was performed assuming a 10 times<br />

larger containment leakage. The RB<br />

annulus exhaust air system was<br />

assumed to be in operation as in the<br />

base case. It sucks steam-air mixture<br />

from one selected location of the RB<br />

annulus at about 12 m level. Figure 3<br />

compares the hydrogen concentration<br />

and Figure 4 the aerosol concentration<br />

in the base case and the variant<br />

calculation. The overall behaviour in<br />

the RB annulus is the same, but the<br />

variant with 10 times larger containment<br />

leakage leads to the formation of<br />

combustible gas mixtures (> 4 vol.-%<br />

hydrogen) in the upper annulus area<br />

and a higher aerosol concentration<br />

especially in the early accident phase<br />

with large releases from the reactor<br />

circuit during core melting. The<br />

results show that the RB annulus<br />

exhaust air system is not efficient<br />

enough to keep the H 2 concentration<br />

below the lower combustible limit of<br />

| | Fig. 4.<br />

Aerosol concentration in the RB annulus for base case (left) and variant case (right) with a 10 times larger containment leakage,<br />

both cases with operation of RB annulus exhaust air system.<br />

| | Fig. 5.<br />

Comparison of pressure in the containment (left) and MCCI gas generation (right) for the cases with and without melt relocation.<br />

4 vol.-% H2 in all RB annulus areas.<br />

The following three gas concentration<br />

zones are established (Figure 3 right):<br />

• RB annulus above 16 m with<br />

hydrogen concentrations up to<br />

~ 5 vol.-%.<br />

• RB annulus at ~12 m (leak location)<br />

with low hydrogen concentrations<br />

up to ~ 2 vol.-%.<br />

• RB annulus at ~ 6 m and below<br />

with very low hydrogen concentrations<br />

< 0.1 vol.-%.<br />

Environment and Safety<br />

Investigation of Conditions Inside the Reactor Building Annulus of a PWR Plant of KONVOI Type in Case of Severe Accidents with Increased Containment Leakages ı Ivan Bakalov and Martin Sonnenkalb


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

ENVIRONMENT AND SAFETY 88<br />

2.3 Variant calculation with a<br />

10 times larger containment<br />

leakage and consideration<br />

of a potential melt relocation<br />

into containment sump<br />

As already noted, all previous analyses<br />

conducted by GRS have been performed<br />

assuming no melt relocation<br />

from the reactor cavity into the containment<br />

sump after melt penetration<br />

of the biological shield. Since the melt<br />

is very likely to melt-through the biological<br />

shield, a variant calculation<br />

with a 10 times larger containment<br />

leakage and a failure of the RB annulus<br />

exhaust air system was performed<br />

assuming melt relocation into the<br />

containment sump.<br />

After penetration of the biological<br />

shield, the corium spreads into the<br />

containment sump and comes into<br />

contact with the sump water. This<br />

results in a higher steam generation,<br />

which in turn leads to a faster longterm<br />

containment pressurization<br />

compared to the case without melt<br />

relocation (Figure 5). Because of the<br />

higher steam production, the filtered<br />

containment venting starts significantly<br />

earlier than in the case without<br />

melt relocation.<br />

Shortly after the melt relocation<br />

into the sump, the corium solidifies<br />

within a very short time period and<br />

the generation of combustible gases<br />

(H 2 and CO) is terminated. Due to the<br />

overall lower gas production, the H 2<br />

concentrations in the containment,<br />

and thus also in the RB annulus, are<br />

significantly lower compared to those<br />

| | Fig. 6.<br />

Comparison of H 2 concentration in the containment (left) and H 2 concentration in the RB annulus (right) for the cases with and<br />

without melt relocation.<br />

| | Fig. 7.<br />

Comparison of containment pressure (left) and H2 mass generated during MCCI (right) for the MBL and ND* base cases.<br />

in the calculations without melt<br />

relocation (Figure 6) and the lower<br />

combustible limit is no longer reached<br />

in the RB annulus.<br />

2.4 Effect of the selected severe<br />

accident scenarios on the<br />

accident consequences<br />

In order to investigate the effect on<br />

the accident consequences, the results<br />

of the two analyzed severe accident<br />

scenarios (MBL and ND*) have been<br />

compared for the base cases with<br />

increased containment leakages.<br />

A comparison of the containment<br />

pressure response calculated for<br />

the two base cases with increased<br />

containment leakages is shown in<br />

Figure 7 (left). The comparison<br />

demonstrate that in the ND* base<br />

case, the filtered containment venting<br />

starts about 16 hours earlier than in<br />

the MBL base case. Figure 7 (right)<br />

depicts a comparison of the hydrogen<br />

mass generated during the MCCI for<br />

the two accident scenarios. Because of<br />

the earlier venting in the ND* base<br />

case, less hydrogen is generated until<br />

the start of containment depressurization.<br />

This is due to the fact that in the<br />

ND* base case the MCCI duration is<br />

shorter than that in the MBL base<br />

case. Hence, for the ND* case, a total<br />

amount of hydrogen of about 3,700 kg<br />

is generated, while for the MBL case,<br />

the total hydrogen mass, generated<br />

until the start time of filtered containment<br />

venting, is about 4,000 kg. The<br />

hydrogen concentrations in the RB<br />

annulus calculated for the two base<br />

case scenarios are compared in<br />

Figure 8. Due to the earlier start of<br />

containment venting in the ND* base<br />

case the maximum hydrogen concentration<br />

in the RB annulus is lower than<br />

that in the MBL base case. From the<br />

comparison it is evident that the<br />

hydrogen lower combustible limit of<br />

4 vol.% is not exceeded until the<br />

beginning of the containment depressurization.<br />

| | Fig. 8.<br />

Comparison of H 2 concentration in the RB annulus ring (left) and H 2 concentration in the RB annulus rooms (right) for the MBL and<br />

ND* base cases.<br />

2.5 Variant calculations with a<br />

10 times larger containment<br />

leakage and AM measures<br />

As part of the assessment of potential<br />

mitigative AM measures the efficiency<br />

of the RB annulus air supply/suction<br />

system to reduce the hydrogen concentration<br />

in the RB annulus was<br />

investigated. For this purpose, a<br />

variant calculation with a 10 times<br />

larger design leakage and a failure of<br />

the RB annulus exhaust air system<br />

was carried out (Figure 9 left) and<br />

another one assuming that the RB air<br />

supply/exhaust systems are put into<br />

Environment and Safety<br />

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<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

operation as AM measure at approx.<br />

50 h after the accident onset (Figure 9<br />

right). The results show a significantly<br />

increased hydrogen concentration in<br />

the RB annulus in case of a failure of<br />

the RB annulus exhaust air system<br />

(Figure 9 left).<br />

Further, in this case the use of<br />

the RB annulus air supply/exhaust<br />

systems is efficient to reduce the<br />

hydrogen concentration and prevent<br />

the formation of combustible gas<br />

mixtures in the annulus rooms. With<br />

the operation of the system the hydrogen<br />

is removed from the annulus<br />

quickly and the hydrogen concentration<br />

remains below 1 vol.-% for the<br />

long term. In that case, the use of the<br />

emergency air filtration system of the<br />

plant is needed in addition to limit<br />

the radionuclide releases into the<br />

environment.<br />

In addition, a possible alternative<br />

method for hydrogen reduction in the<br />

annulus was investigated assuming<br />

the installation of a small number of<br />

medium size PARs in the upper RB<br />

annulus (Figure 10 right). The results<br />

are compared with a variant calculation<br />

with a 10 times larger design<br />

leakage and failure of the RB annulus<br />

exhaust air system (Figure 10 left).<br />

The results show that already the<br />

implementation of PARs of medium<br />

size can significantly reduce the<br />

hydrogen concentration in the RB<br />

annulus and keep it well below<br />

lower combustible limits. The hydrogen<br />

depletion starts at approx. 40 h<br />

(150,000 s) after the accident onset<br />

if the concentration exceeds about<br />

1 to 2 vol.-%. Thus, an AM concept<br />

with the installation of some PARs in<br />

the annulus is considered a very<br />

efficient mitigation measure for preventing<br />

formation of combustible gas<br />

mixtures in the RB annulus not just in<br />

the case presented.<br />

3 Conclusions<br />

The behaviour of hydrogen as well as<br />

aerosol and noble gases released into<br />

the reactor building annulus of a<br />

German PWR KONVOI reference plant<br />

resulting from increased containment<br />

leakages under severe accident conditions<br />

was investigated using the<br />

GRS code COCOSYS. Two representative<br />

and different severe accident<br />

scenarios – the base cases – have been<br />

selected for the analyses.<br />

The calculation results show no<br />

formation of combustible gas mixtures<br />

in the RB annulus during the observation<br />

period for the base case with<br />

containment design leakage and<br />

operation of RB annulus exhaust<br />

| | Fig. 9.<br />

H 2 concentration in the RB annulus for variant cases with 10 times larger leakages and failure of RB annulus exhaust air system (left)<br />

and with AM measure “operation of RB annulus air supply/exhaust systems” (right).<br />

| | Fig. 10.<br />

H 2 concentration in the RB annulus for variant cases with 10 times larger leakages and failure of RB annulus exhaust air system (left)<br />

and with AM measure “PARs in the RB annulus” (right).<br />

air system. It was identified that in<br />

this case separate annulus rooms are<br />

isolated at an early stage by the automatic<br />

closing of fire protection doors,<br />

thus preventing a further increase in<br />

the hydrogen concentration in these<br />

rooms.<br />

In contrast, the variant calculation<br />

with a 10 times larger containment<br />

design leakage leads to formation of<br />

combustible mixtures in the upper RB<br />

annulus area. In this case, the RB<br />

annulus exhaust air system is not<br />

efficient enough to prevent formation<br />

of combustible gas mixtures in the<br />

upper RB annulus area.<br />

Further, the variant calculation<br />

assuming melt relocation into the<br />

containment sump demonstrated that<br />

the corium spreading into the sump<br />

results in a higher steam generation,<br />

which leads to a faster long-term<br />

containment pressurization. After the<br />

melt relocation into the sump, the<br />

corium solidifies within a short time<br />

and the generation of combustible<br />

gases (H 2 and CO) coming from<br />

MCCI is terminated. As a result, the<br />

H 2 concentrations in the containment<br />

as well as in the RB annulus are<br />

significantly lower compared to those<br />

in the case without melt relocation. In<br />

this case, the lower combustible limit<br />

of 4 vol.% in the RB annulus is no<br />

longer reached.<br />

Moreover, the results of the two<br />

analyzed severe accident scenarios<br />

(MBL and ND*) were compared in<br />

order to investigate their effect on<br />

the accident consequences. From the<br />

comparison it was identified that in<br />

the ND* base case, the filtered<br />

containment venting starts about<br />

16 hours earlier than in the MBL base<br />

case. As a result, the maximum hydrogen<br />

concentration in the RB annulus,<br />

calculated for the ND* base case, is<br />

lower than that in the MBL base case.<br />

The comparison showed that in the<br />

ND* base case the hydrogen concentration<br />

does not exceed the lower<br />

combustible limit of 4 vol.% until the<br />

beginning of the containment depressurization.<br />

Within the scope of the project, the<br />

efficiency of different AM measures<br />

for mitigation of accident consequences<br />

in the reactor building annulus<br />

was analyzed. The assessment<br />

results show that the operation of RB<br />

annulus air supply/suction system<br />

significantly reduces the hydrogen<br />

concentration and prevents formation<br />

of combustible gas mixtures in RB<br />

annulus. Therefore, the use of these<br />

ventilation systems is considered as a<br />

very promising accident management<br />

measure for reducing the hydrogen<br />

concentration in the reactor building<br />

annulus. However, in that case the<br />

ENVIRONMENT AND SAFETY 89<br />

Environment and Safety<br />

Investigation of Conditions Inside the Reactor Building Annulus of a PWR Plant of KONVOI Type in Case of Severe Accidents with Increased Containment Leakages ı Ivan Bakalov and Martin Sonnenkalb


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

ENVIRONMENT AND SAFETY 90<br />

emergency air filtration system of<br />

the plant is needed in addition to limit<br />

the radionuclide releases into the<br />

environment.<br />

With respect to mitigation of the<br />

hydrogen risk in the annulus it is<br />

demonstrated that the implementation<br />

of a small number of PARs would<br />

be a very efficient and fully passive<br />

mitigation measure without additional<br />

aerosol release into the environment.<br />

Acknowledgments<br />

The authors like to acknowledge the<br />

German Federal Ministry for the<br />

Environment, Nature Conservation,<br />

Building and Nuclear Safety for the<br />

financial support of the project<br />

3615R01345.<br />

References<br />

[1] Recommendation of German Reactor<br />

Safety Commission (RSK): Hydrogen<br />

Release from Containment. Annex of<br />

the Proceedings of 475 th meeting of<br />

RSK, 15.04.2015.<br />

[2] Band, S., Schwarz, S., Sonnenkalb, M.:<br />

Nachweis der Wirksamkeit von<br />

H 2 -Rekombinatoren auf der Basis<br />

ergänzender analytischer Untersuchungen<br />

mit COCOSYS für die<br />

Referenzanlage GKN-2. Final Report<br />

of BMUB project 3609R01375,<br />

GRS-A-3652, March 2012.<br />

[3] Schwarz, S., Sonnenkalb, M.: Analyse<br />

der Belastung von Gleitdruckventuriwäschern<br />

in SHB-Ventingsystemen<br />

von DWR KONVOI und<br />

SWR-72 bei Unfällen. Final Report<br />

of BMUB project 3613R01320,<br />

GRS-A-3820, August 2015.<br />

Authors<br />

Ivan Bakalov<br />

Research Fellow<br />

Gesellschaft für Anlagen- und<br />

Reaktorsicherheit (GRS) gGmbH,<br />

Kurfürstendamm 200<br />

10719 Berlin, Germany<br />

Dr. Martin Sonnenkalb<br />

Department Head<br />

Gesellschaft für Anlagen- und<br />

Reaktorsicherheit (GRS) gGmbH,<br />

Schwertnergasse 1<br />

50667 Cologne, Germany<br />

Sensitivity Analysis of MIDAS Tests Using<br />

SPACE Code: Effect of Nodalization<br />

Shin Eom, Seung-Jong Oh and Aya Diab<br />

1 Introduction The SPACE thermal hydraulic analysis computer code has been developed by KHNP (Korea<br />

Hydro and Nuclear Power) [1]. The SPACE code is based on the three-field governing equations (vapor, continuous<br />

liquid, and droplet). It improves the accuracy by solving the mass, energy, and momentum conservation equations for<br />

each phase and adopts the proven numerical methods as well as the models for various thermal hydraulic phenomena.<br />

With the new code, the best estimate<br />

LOCA (Loss Of Coolant Accident)<br />

methodology needs to be reestablished.<br />

For APR1400 LBLOCA (Large<br />

Break LOCA, APR1000: Advanced<br />

Power Reactor 1000 MWe), KREM [2]<br />

has been developed one of the best<br />

estimate methodology using RELAP5<br />

code [3, 4]. With the new code, one<br />

needs to look at the code performance<br />

to develop best estimate + uncertainty<br />

method. In this paper, as a part of the<br />

development effort, we focus on the<br />

impact of nodalization on the code<br />

predictions, more specifically, on the<br />

ECC bypass phenomenon.<br />

For APR1400 LBLOCA, ECC bypass<br />

phenomenon is one of the important<br />

phenomena which would occur in the<br />

downcomer during the reflood phase<br />

of LOCA [5]. To study the ECC bypass<br />

phenomenon, KAERI carried out the<br />

ECC bypass tests using the MIDAS<br />

facility [6, 7, 8]. MIDAS simulation is a<br />

part of the assessment of the KREM.<br />

One of the important parameters<br />

for the MIDAS test is ECC bypass fraction.<br />

The results for each nodalization<br />

were compared with MIDAS test data.<br />

The main aim of this study is therefore<br />

to examine the sensitivity of the<br />

SPACE code to the number of thermal<br />

hydraulic channels in the downcomer<br />

region.<br />

| | Fig. 1.<br />

Isometric View of the MIDAS Facility [7].<br />

| | Fig. 2.<br />

Top View of the MIDAS Facility Downcomer [7].<br />

2 MIDAS test<br />

The MIDAS test facility is a steamwater<br />

separate effect test facility<br />

which is scaled down from APR1400<br />

[9]. It is focused on the investigation<br />

of the ECC bypass phenomenon in the<br />

downcomer annulus. The test condition<br />

was determined, based on the<br />

analysis of the TRAC (Transient<br />

Reactor Analysis Code) [10]. The<br />

isometric and top view of the MIDAS<br />

facility is depicted in Figure 1 and<br />

Figure 2.<br />

To investigate the effect of the DVI<br />

injection nozzle location on the ECC<br />

bypass fraction, fifteen separate effect<br />

Environment and Safety<br />

Sensitivity Analysis of MIDAS Tests Using SPACE Code: Effect of Nodalization ı Shin Eom, Seung-Jong Oh and Aya Diab


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

tests have been performed with only<br />

DVI-2 (farthest from the broken cold<br />

leg), only DVI-4 (closest to the broken<br />

cold leg), and DVI-2&4 with both<br />

injection nozzles activated. Table 1<br />

provides the experimental conditions<br />

for the 15 tests.<br />

The bypass fractions of the MIDAS<br />

experiment for the test conditions are<br />

presented in the Figure 3. The test<br />

results show that the ECC bypass<br />

fraction is highly dependent on the<br />

injection nozzle location with respect<br />

to the broken leg as well as the injected<br />

steam flow rate.<br />

Injecting through the nozzle closet<br />

to the broken leg (DVI-4 tests)<br />

show that the direct bypass fraction<br />

increases drastically for a steam flow<br />

rate above 0.7 kg/s. This is expected<br />

since at a higher steam flow rate, the<br />

relative speed between the two fluid<br />

streams becomes higher resulting in a<br />

higher shear effect.<br />

On the other hand, injecting<br />

through the nozzle farthest to the<br />

broken leg (DVI-2 test) dramatically<br />

decreases the bypass fraction, and<br />

accordingly most of the injected ECC<br />

water penetrates into the lower downcomer.<br />

This is primarily due to the<br />

lower interfacial interaction between<br />

the two streams. As a result of the<br />

spatial separation, the ECCS stream<br />

becomes more inertially driven.<br />

With both nozzles activated<br />

( DVI-2&4 tests), the bypass ratio<br />

increases with steam flow rate but<br />

at a much slower rate as compared<br />

to that of DVI-4 tests. This may be<br />

attributed to lower interfacial-interaction<br />

between the injected steam and<br />

ECCS stream for the combined case.<br />

Test<br />

No.<br />

Steam<br />

in (kg/s)<br />

ECCS Injection<br />

Nozzle<br />

KM100 1.7924 DVI-2&4<br />

KM101 1.6149 DVI-2&4<br />

KM1<strong>02</strong> 1.3753 DVI-2&4<br />

KM103 1.1711 DVI-2&4<br />

KM104 0.0493 DVI-2&4<br />

KM105 0.9378 DVI-2&4<br />

KM106 0.8592 DVI-2&4<br />

KM107 0.8096 DVI-2&4<br />

KM108 0.7540 DVI-2&4<br />

KM109 1.8086 DVI-2<br />

KM110 1.0555 DVI-4<br />

KM111 0.8995 DVI-4<br />

KM112 0.7991 DVI-4<br />

KM113 0.7360 DVI-4<br />

3 MIDAS Modeling<br />

for the SPACE Code<br />

A SPACE model of the MIDAS facility<br />

is developed with three different<br />

nodalization schemes as shown in<br />

Figure 4 to Figure 6. The downcomer<br />

is modeled as an annulus component<br />

with 4, 6, and 12 circumferential<br />

channels. A nodalization sensitivity<br />

analysis for the ECC bypass phenomenon<br />

was performed using the SPACE<br />

code version 3.0.<br />

For the KREM which has best<br />

estimate LOCA methodology using<br />

RELAP5 code, the downcomer was<br />

represented with 6 channels [4]. The<br />

comparison with MIDAS test results as<br />

a part of the code validation showed<br />

that RELAP5 code over-predicts the<br />

bypass fraction for low steam flow<br />

cases while predicts reasonably for<br />

higher steam flow cases.<br />

The intact cold legs (CL-1, CL-2,<br />

and CL-3) are connected to the<br />

annulus component using a normal<br />

junction with branch components. A<br />

time-dependent volume and a<br />

time-dependent junction were used to<br />

admit the steam flow rate through<br />

each cold leg. The broken cold leg<br />

(CL-4) is connected to the annulus<br />

component using a normal junction<br />

with a branch component.<br />

The DVI nozzle (DVI-4) closest to<br />

the broken leg is connected to the<br />

same hydraulic channel as the break<br />

(CL-4) whereas the DVI nozzle<br />

(DVI-2) farthest from the break shares<br />

the same hydraulic channel as the<br />

intact cold leg (CL-1) as shown in<br />

Figure 4 to Figure 6. The drain valve<br />

was modeled using a trip valve<br />

component which would open if the<br />

water level of the lower downcomer<br />

becomes higher than the set point.<br />

The hot legs, (HL-1 and HL-2)<br />

which are located between CL-1 and<br />

CL-2, and between CL-3 and CL-4,<br />

respectively, are modeled as blunt<br />

bodies that penetrate the downcomer.<br />

The flow areas were calculated by<br />

using the gap width, perimeter, as<br />

well as other geometric parameters at<br />

this section to estimate the equivalent<br />

thermal hydraulic diameter.<br />

The direct ECCS bypass fraction<br />

is calculated based on the flow rates<br />

of ECCS injection, steam injection,<br />

and drain flow rate at the lower downcomer<br />

as follows:<br />

Bypass fraction =<br />

M Water_out<br />

M SI_in +M Condensate<br />

| | Fig. 3.<br />

ECC Bypass Fraction of MIDAS Tests.<br />

M Steam_in is the steam injection mass<br />

flow rate, and M Condensate is the<br />

condensate mass flow rate calculated<br />

as follows:<br />

M Condensate = M Steam_in – M Steam_out<br />

4 Results and Discussion<br />

The model predictions of the bypass<br />

fraction for all three nodalization<br />

cases (4, 6 and 12 channels) were<br />

compared to the experimental data.<br />

The sample standard deviation of the<br />

differences between measured values<br />

and predicted values, RMSE (Root<br />

Mean Square Error), are presented in<br />

Table 2.<br />

For the case with DVI-2 injection<br />

only (KM109), the RMSEs are<br />

relatively small and acceptable for all<br />

three cases with 0.056 for 4 channels<br />

as a representative case. For the<br />

injection through DVI-4 only (KM110<br />

~ KM114), the code over-predicts the<br />

bypass fraction. This is more distinct<br />

at lower steam flow and for finer<br />

nodalization (e.g. 12 channels). For<br />

the cases with injection through both<br />

ENVIRONMENT AND SAFETY 91<br />

KM114 0.6879 DVI-4<br />

| | Tab. 1.<br />

Experimental Conditions of MIDAS Tests [7].<br />

where, M SI_in is the total ECCS injection<br />

mass flow rate, M Water_out is the<br />

discharged liquid mass flow rate,<br />

| | Fig. 4.<br />

MIDAS Nodalization Scheme with 4 Channels.<br />

Environment and Safety<br />

Sensitivity Analysis of MIDAS Tests Using SPACE Code: Effect of Nodalization ı Shin Eom, Seung-Jong Oh and Aya Diab


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

ENVIRONMENT AND SAFETY 92<br />

| | Fig. 5.<br />

MIDAS Nodalization Scheme with 6 Channels.<br />

| | Fig. 6.<br />

MIDAS Nodalization Scheme with 12 Channels.<br />

Test No.<br />

Steam Flow Rate<br />

(kg/s)<br />

| | Tab. 2.<br />

RMSE Calculated Results of Bypass Fraction with Measured Data.<br />

DVI-2 and DVI-4, the steam flow<br />

rate seems to govern the prediction<br />

accuracy. In case of high steam flow<br />

rate tests (≥ 1.1 kg/s), the SPACE<br />

code predicted the bypass fraction<br />

well regardless of the number of<br />

channels chosen. For the low steam<br />

flow rate tests (≤ 1.1 kg/s), the RMSE<br />

is ≥ 0.16 as shown in Table 2. More<br />

detailed examination is presented<br />

below.<br />

4.1 Results of High Steam Flow<br />

Rate Tests<br />

The results for the high steam flow<br />

rate tests (KM100 ~ KM103, and<br />

Number of Channels<br />

4 6 12<br />

KM109 1.8086 0.056 0.078 0.005<br />

KM100 ~ 103 ≥ 1.1 0.017 0.019 0.017<br />

KM104 ~ 108<br />

0.161 0.211 0.287<br />

≤ 1.1<br />

KM110 ~ 114 0.252 0.334 0.462<br />

| | Fig. 7.<br />

Comparison of the Measured and Calculated ECC Bypass Fraction for the<br />

High Steam Flow Cases.<br />

KM109) are presented in Figure 7. For<br />

the high steam flow rate tests, the<br />

SPACE code predicts the bypass<br />

fraction relatively well for all<br />

nodalization cases.<br />

The liquid flow pattern for the<br />

KM100 test (highest steam flow rate<br />

test) of each nodalization case are<br />

presented in Figure 8 to Figure 10.<br />

The liquid flow pattern for the all<br />

nodalization cases are quite similar.<br />

The direct bypass phenomena occurs<br />

in the upper region of the downcomer<br />

as the ECCS flow joins the high<br />

velocity steam from the intact cold leg<br />

and is swept away through the broken<br />

cold leg. In the case of tests with a<br />

high steam flow rate, the result of<br />

the 4 channels nodalization is similar<br />

to that of 6 and 12 channels. Hence,<br />

the 4 channels representation is considered<br />

a reasonable approximation.<br />

4.2 Results of Low Steam Flow<br />

Rate Tests<br />

The results for the low steam flow rate<br />

tests (KM104 ~108 and KM110 ~114)<br />

are presented in Figure 11. Contrary<br />

to the high steam flow rate cases, for<br />

the low steam flow rate tests, the<br />

SPACE code over-predicts the bypass<br />

fraction for the all nodalization cases.<br />

The liquid and vapor flow patterns<br />

of the 6 channels case for the lowest<br />

steam flow rate test (KM114) are<br />

presented in Figure 12 and Figure 13,<br />

respectively. Most of the liquid<br />

injected from the DVI nozzle is swept<br />

with the steam flow through the<br />

break. The test indicated some downward<br />

liquid flow at this steam flow<br />

rate.<br />

In the SPACE code, the interfacial<br />

friction model is dependent on the<br />

flow regime of the control volume.<br />

Thus, for quantitative agreement with<br />

the MIDAS experimental measurements,<br />

the estimation of the flow<br />

regime has to be properly predicted to<br />

accurately estimate the bypass flow in<br />

the upper downcomer. The SPACE<br />

code selects the annular mist flow<br />

regime based on the volume average<br />

conditions, which explains the deviation<br />

between the code prediction and<br />

MIDAS tests in the case of low steam<br />

flow rate.<br />

4.3 Results of Condensation<br />

Fraction<br />

It is worthy to note that for all the<br />

studied cases, the code under-predicts<br />

the condensation fraction as shown in<br />

the Figure 14. The RMSE based on<br />

calculated condensation fraction with<br />

the measured condensation fraction<br />

data are presented in Table 3. The<br />

under-prediction tendency is more<br />

distinct for finer nodalization (e.g. 12<br />

channels) as depicted in Table 3. This<br />

may clearly be tied to the heat transfer<br />

correlation which in turn depends on<br />

the flow regime. Due to mass conservation,<br />

the lower condensation rate<br />

leads to over-estimation of the bypass<br />

Environment and Safety<br />

Sensitivity Analysis of MIDAS Tests Using SPACE Code: Effect of Nodalization ı Shin Eom, Seung-Jong Oh and Aya Diab


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

| | Fig. 8.<br />

Liquid Flow Pattern of KM100 Test Calculation<br />

with 4 Channels Nodalization.<br />

| | Fig. 9.<br />

Liquid Flow Pattern of KM100 Test Calculation<br />

with 6 Channels Nodalization.<br />

| | Fig. 10.<br />

Liquid Flow Pattern of KM100 Test Calculation<br />

with 12 Channels Nodalization.<br />

ENVIRONMENT AND SAFETY 93<br />

| | Fig. 11.<br />

Comparison of the Measured and Calculated ECC Bypass Fraction for Low<br />

Steam Flow Cases.<br />

| | Fig. 12.<br />

Liquid Flow Pattern of KM114 Test Calculation<br />

with 6 Channels Nodalization.<br />

| | Fig. 13.<br />

Vapor Flow Pattern of KM114 Test Calculation<br />

with 6 Channels Nodalization.<br />

fraction. The problem is aggravated<br />

for the lower steam flow rate tests,<br />

since the phase change effect overshadows<br />

the convective effect. It is<br />

hypothesized that the bypass flow<br />

may be influenced by the interplay<br />

between thermal and inertial effects,<br />

particularly at the lower steam flow<br />

rate test conditions.<br />

5 DVI Location Effect for<br />

the Low Steam Flow Rate<br />

Test<br />

As shown in the Figure 4 to Figure 6,<br />

the DVI channels and the broken<br />

channel share the same channel. With<br />

this nodalization, the most of the<br />

injected liquid flows into the control<br />

volume directly connected to broken<br />

cold leg. Since the steam flow for this<br />

volume is very high, the flow regime<br />

becomes co-current annular mist flow.<br />

With co-current annular flow, the<br />

injected water from the DVI swept<br />

away to the break.<br />

To further examine this phenomenon,<br />

we carried out an additional<br />

calculation. We selected the 6 channels<br />

representation. This time, however,<br />

the DVI-4 is connected to a<br />

channel next to the channel where<br />

broken cold leg is connected as shown<br />

in the Figure 15. The DVI channels<br />

were separated from the broken channel<br />

(or cold leg channel), artificially.<br />

The bypass and condensation<br />

fraction results of the existing and new<br />

nodalization cases with 6 channels are<br />

compared with KM114 test conditions<br />

in Table 4. Clearly, the new nodalization<br />

better predicts the bypass and<br />

condensation fraction. While the<br />

existing nodalization predicts a bypass<br />

fraction of 0.714, the new nodalization<br />

predicts a bypass fraction of 0.091<br />

with only about 16 % deviation.<br />

| | Fig. 14.<br />

Comparison of the Measured and Calculated Condensation Fraction.<br />

| | Fig. 15.<br />

New Nodalization Scheme for 6 Channels.<br />

Test No.<br />

Steam Flow Rate<br />

(kg/s)<br />

Number of Channels<br />

4 6 12<br />

Case<br />

Bypass<br />

Fraction<br />

Condensation<br />

Fraction<br />

KM109 1.8086 0.<strong>02</strong>9 0.036 0.052<br />

KM100 ~ 103 ≥ 1.1 0.078 0.094 0.116<br />

KM104 ~ 108<br />

0.090 0.113 0.144<br />

≤ 1.1<br />

KM110 ~ 114 0.082 0.103 0.138<br />

| | Tab. 3.<br />

RMSE Calculated Results of Condensation Fraction with Measured Data.<br />

Measured value 0.109 0.231<br />

Existing nodalization 0.714 0.131<br />

New nodalization 0.091 0.203<br />

| | Tab. 4.<br />

Bypass and Condensation Fraction Results Comparison<br />

in Case of 6 Channels for KM114 Test.<br />

Environment and Safety<br />

Sensitivity Analysis of MIDAS Tests Using SPACE Code: Effect of Nodalization ı Shin Eom, Seung-Jong Oh and Aya Diab


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

ENVIRONMENT AND SAFETY 94<br />

| | Fig. 16.<br />

Liquid Flow Pattern of KM114 Test Calculation<br />

with 6 Channels of New Nodalization.<br />

Similarly, while the existing nodalization<br />

predicts a condensation fraction<br />

of 0.131, the new nodalization predicts<br />

a condensation fraction of 0.203 with<br />

only about 12 % deviation.<br />

The liquid and vapor flow pattern<br />

diagrams of the 6 channels case for<br />

the KM114 test are presented in<br />

Figure 16 and Figure 17 for the new<br />

nodalization, respectively. The liquid<br />

flow issuing from DVI-4 becomes<br />

continuous downward flow as shown<br />

in Figure 16. This shows the importance<br />

of proper representation of the<br />

flow regime. Given that the new<br />

nodalization does not strictly reflect<br />

the actual experimental arrangement,<br />

the proper nodalization scheme needs<br />

to be further developed.<br />

6 Conclusions<br />

In this paper, a nodalization sensitivity<br />

analysis for the MIDAS test was<br />

performed using the SPACE code.<br />

Three cases were modeled: 4, 6, and<br />

12 channels.<br />

In the case of high steam flow rate<br />

with DVI injection from both sides<br />

tests (KM100 ~ KM103) and DVI-2<br />

injection test (KM109), the SPACE<br />

code estimated the bypass fraction<br />

relatively accurately and the nodalization<br />

scheme does not affect<br />

the code results much. From the<br />

efficiency, 4 channel representation<br />

is recommended for SPACE code<br />

nodalization.<br />

Similar to RELAP5 calculation, the<br />

SPACE code was unable to accurately<br />

predict the bypass fraction for the low<br />

steam flow rate MIDAS tests (KM104<br />

~ 108 and KM 110 ~ 114) regardless<br />

of the nodalization used. From a<br />

safety perspective, over-prediction of<br />

the bypass flow is conservative for a<br />

LOCA simulation.<br />

The over-prediction at low steam<br />

flow may be attributed to the difficulty<br />

to correctly represent the flow regime<br />

in the vicinity of the broken cold leg.<br />

This led to under-prediction of<br />

| | Fig. 17.<br />

Vapor Flow Pattern of KM114 Test Calculation<br />

with 6 Channels of New Nodalization.<br />

condensation rate and over-prediction<br />

of interfacial shear. When the DVI<br />

channels were horizontally shifted<br />

with respect to the break channel, the<br />

SPACE better predicted the bypass<br />

fraction for the lowest steam flow rate<br />

MIDAS test (KM114). This fictitious fix<br />

proves the hypothesis but the result<br />

should be treated with discretion.<br />

7 Acknowledgments<br />

This research was supported by the<br />

2017 Research Fund of the KINGS<br />

(KEPCO International Nuclear<br />

Graduate School), Republic of Korea.<br />

References<br />

[1] ***, KHNP, Topical Report on the SPACE<br />

code for Nuclear Power Plant Design,<br />

KHNP/TR-0032/2017, 2017.<br />

[2] S.Y. Lee and C.H. Ban, Code-Accuracy-<br />

Based Uncertainty Estimation (CABUE)<br />

Methodology for Large-Break Loss-of-<br />

Coolant Accidents, Nuclear Technology,<br />

Vol. 148 Issue 3, pp.335-347, 2004.<br />

[3] ***, KHNP, Topical Report for the<br />

LBLOCA Best-Estimate Evaluation<br />

Methodology of the APR1400 Type<br />

Nuclear Power Plant, KHNP/TR-0018/<br />

2010, 2010.<br />

[4] S.W. Lee and S.J. Oh, APR1400 Large<br />

Break Loss of Coolant Accident Analysis<br />

using KREM methodologies, 2003 KNS<br />

Autumn Meeting, KNS, 2003.<br />

[5] S.W. Lee, H.G. Kim, and S.J. Oh,<br />

Assessment of APR1400 ECCS Capability<br />

against Large-Break LOCA Scenario<br />

by RELAP5/MOD3 Code, Nuclear<br />

Technology, Vol. 158 Issue 3,<br />

pp.396-407, 2007.<br />

[6] B.J. Yun, H.K. Cho, T.S. Kwon, C.H. Song,<br />

J.K. Park, and G.C. Park, Experimental<br />

Observation on the Hydraulic<br />

Phenomena in the KNGR Downcomer<br />

during LBLOCA Reflood Phase, 2000<br />

KNS Spring Meeting, KNS, 2000.<br />

[7] ***, KAERI, Direct Vessel Injection Test<br />

Using the MIDAS Test Facility-ECC Direct<br />

Bypass Test, MIDAS-QLR-009, 2001.<br />

[8] W.A. Carbiener and R.A. Cudnik,<br />

Similitude Considerations for Modeling<br />

Nuclear Reactor Blowdowns, Tran. Am.<br />

Nucl. Soc., Vol. 12, pp.361, 1969.<br />

[9] B.J. Yun et al., Direct ECC Bypass<br />

Phenomena in the MIDAS Test Facility<br />

during LBLOCA Reflood Phase,<br />

KNS Vol. 34, pp.421-432, 20<strong>02</strong>.<br />

[10] ***, KAERI, Scaling Analysis of the<br />

Thermal Hydraulic Test Facility for the<br />

Large Break LOCA of KNGR, KAERI/<br />

TR-1878/2001, 2001.<br />

Authors<br />

Shin Eom<br />

Graduate Student<br />

Professor Dr. Seung-Jong Oh<br />

Professor Dr. Aya Diab<br />

Department of NPP Engineering<br />

KEPCO International Nuclear<br />

Graduate School (KINGS)<br />

Ulsan, Korea<br />

Environment and Safety<br />

Sensitivity Analysis of MIDAS Tests Using SPACE Code: Effect of Nodalization ı Shin Eom, Seung-Jong Oh and Aya Diab


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

The Application of Knowledge<br />

Management and TRIZ for solving the<br />

Safe Shutdown Capability in Case of Fire<br />

Alarms in Nuclear Power Plants<br />

Chia-Nan Wang, Hsin-Po Chen, Ming-Hsien Hsueh and Fong-Li Chin<br />

1 Introduction The 2011 the Fukushima nuclear disaster in Japan was caused by a failure in the safe shutdown<br />

system. The severing of power systems incapacitated several of the shutdown devices, thereby hindering the removal of<br />

excess heat from the reactor. Under these conditions, zirconium on the protective cover of the fuel rods reacted with the<br />

cooling water to produce hydrogen gas. The resulting explosion fractured the containment building, thereby allowing<br />

the escape of radioactive materials into the surrounding environment.<br />

Nuclear power plants designed in<br />

the U.S. must conform to regulations<br />

outlined by the Nuclear Regulatory<br />

Commission (NRC). The safe shutdown<br />

capabilities of a facility are<br />

documented in the Final Safety<br />

Analysis Report (FSAR), which must<br />

be submitted to authorities prior to<br />

the licensing of operations. Facility<br />

upgrades are also subject to approval.<br />

Operating specifications include<br />

shut-down procedures to be implemented<br />

in the event of an earthquake<br />

or other environmental disaster. In<br />

1979, the NRC proposed a number of<br />

fire safety measures [10CFR50 App.R];<br />

however, the complexity of nuclear<br />

facilities has greatly hindered implementation<br />

and enforcement. Nuclear<br />

power plants are required to have two<br />

independent safe shutdown systems,<br />

either of which must be able to<br />

manage plant operations during the<br />

transition from operating phase to<br />

cold shutdown. The simultaneous<br />

failure of both of systems would lead<br />

to a catastrophic collapse of the entire<br />

system. This study sought to sought to<br />

improve the safe shutdown performance<br />

of nuclear power plants in the<br />

event of fire. We compiled a wide<br />

range of data pertaining to post-fire<br />

safe shutdown of nuclear power<br />

plants, while dealing with each system<br />

and its components as discrete units.<br />

Our main objectives were as follows:<br />

1. To compile a knowledge base<br />

of issues related to hazards in<br />

nuclear power plants: The<br />

knowledge base defines the safe<br />

shutdown system used in each fire<br />

zone, describes the components<br />

used in each system, and organizes<br />

the shutdown processes in the<br />

form of a flowchart.<br />

2. To assess the components of the<br />

safe shutdown systems using the<br />

Teoriya Resheniya Izobreatatelskih<br />

Zadatch (TRIZ) method:<br />

We defined the attributes and<br />

parameters of various problems<br />

associated with safe shutdown<br />

equipment and developed models<br />

for each individual problem using<br />

TRIZ to identify feasible means of<br />

improvement.<br />

3. Improve the safety regulations<br />

of nuclear power plants based<br />

on case studies and a literature<br />

review: We formulated a novel<br />

approach to the analysis of case<br />

studies with the aim of facilitating<br />

the identification of omissions<br />

and flaws in current evaluation<br />

standards.<br />

2 Literature review<br />

Prior to 1974, there were only two<br />

clauses in the national fire regulations<br />

(U.S.): 10CFR50 Appendix A (fire<br />

protection) General Design Criteria<br />

(GDC) and R.G 1.70.4. In November<br />

1975, after the fire at Browns Ferry<br />

Nuclear Power Plant, the NRC<br />

published the Standard Review Plan<br />

9.5-1. In May 1976, the BTP APCSB<br />

9.5-1App.A (Nuclear Power Plant<br />

Fire Guidelines) came into effect for<br />

nuclear power plants seeking to obtain<br />

building permits after July 1 [NRC,<br />

1976], 1976. In August 1977, the NRC<br />

published the Generic Letter 77-<strong>02</strong><br />

[USNRC, 1977], addressing issues<br />

pertaining to administration, the<br />

regulation of organizations, firefighting<br />

procedures, and quality<br />

control measures. In 1980, the NRC<br />

drew up 10CFR50 Appendix R (fire<br />

protection program), detailing the<br />

requirements of all nuclear power<br />

plants that went into operation prior<br />

to January 1st 1979. In February 1981,<br />

the NRC announced 10CFR50.48<br />

(fire protection) as the standing<br />

regulations for nuclear power plant<br />

fire safety [Information Notice, 1984].<br />

Compliance with 10 CFR 50 App. R<br />

was not mandatory for all nuclear<br />

power plants operating before<br />

January 1, 1979 (pre-1979 plants);<br />

however, they had to follow the<br />

basic design requirements. In contrast,<br />

nuclear power plants operating<br />

since January 1, 1979 (post-1979<br />

plants) have had to comply with BTP<br />

CMEB 9.5-1, Revision 2 [CRF, 1979]<br />

In the case study of this paper, an<br />

operating license was obtained for<br />

reactor 1 on July 27, 1984. It should<br />

therefore have been subject to BTP<br />

CMEB 9.5-1 Rev.2 [July 1981]; however,<br />

Section 9.5.1 of the FSAR from<br />

the later Maanshan Nuclear Power<br />

Plant refers to Appendix A to APCB<br />

9.5-1 [NRC Branch Technical Position,<br />

1981]. As a result, both were used<br />

as references. Taiwan uses the fire<br />

regulations of 10 CFR 50 Appendix R<br />

as the basis for fire inspections;<br />

however, these regulations are somewhat<br />

rudimentary [TPC, 1999].<br />

In U.S. federal regulations 10<br />

CFR 50 Appendix A, General Design<br />

Criterion 3 specifies the basic fire<br />

protection requirements for nuclear<br />

power plants [CFR, 2012]. For<br />

example, the design of the fire protection<br />

system must ensure that even in<br />

the event of damage of improper use,<br />

the safety performance would not be<br />

impaired. Fire protection policy based<br />

on defense-in-depth is used to protect<br />

the shutdown system as follows:<br />

1) preventing the occurrence of fires,<br />

2) ensuring the rapid detection, control,<br />

and extinguishing of fires that<br />

do occur, and<br />

3) ensuring the normal operation<br />

of the safe shutdown system if a<br />

fire cannot be extinguished [NCR,<br />

1975].<br />

95<br />

OPERATION AND NEW BUILD<br />

Operation and New Build<br />

The Application of Knowledge Management and TRIZ for solving the Safe Shutdown Capability in Case of Fire Alarms in Nuclear Power Plants ı Chia-Nan Wang, Hsin-Po Chen, Ming-Hsien Hsueh and Fong-Li Chin


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

OPERATION AND NEW BUILD 96<br />

In 10 CFR 50 Appendix R, Section<br />

III.G.1 are specified the fire protection<br />

requirements for the emergency<br />

shutdown of nuclear power plants:<br />

1. One train of systems necessary to<br />

achieve and maintain hot shutdown<br />

conditions from either<br />

the control room or emergency<br />

control station(s) is free of fire<br />

damage.<br />

2. Systems necessary to achieve and<br />

maintain cold shutdown from<br />

either the control room or emergency<br />

control station(s) can be<br />

repaired within 72 hours [NRC,<br />

2007].<br />

In 10 CFR 50 Appendix R, Section<br />

III.G.2 are outlined specific isolation<br />

requirements for redundant cables<br />

and safe shutdown systems within the<br />

same fire compartment: “Except as<br />

provided for in paragraph G.3 of this<br />

section, where cables or equipment,<br />

including associated non-safety<br />

circuits that could prevent operation<br />

or cause maloperation due to hot<br />

shorts, open circuits, or shorts to<br />

ground, of redundant trains of systems<br />

necessary to achieve and maintain hot<br />

shutdown conditions are located<br />

within the same fire area outside of<br />

primary containment, one of the<br />

following means of ensuring that<br />

one of the redundant trains is free<br />

of fire damage shall be provided.”<br />

10 CFR 50 Appendix R, Section<br />

III.G.3 specifies the situations in<br />

which fire compartments are required<br />

to have dedicated safe shutdown<br />

capabilities involving modification or<br />

replacement of dedicated cables and/<br />

or circuitry.<br />

Cables, systems and components<br />

should be independent of area, room,<br />

zone if the following conditions are<br />

met:<br />

1. Where the protection of systems<br />

whose function is required for hot<br />

shutdown does not satisfy the<br />

requirement of paragraph G.2 of<br />

this section; or<br />

2. Where redundant trains of systems<br />

required for hot shutdown located<br />

in the same fire area may be subject<br />

to damage from fire suppression<br />

activities or from the rupture or<br />

inadvertent operation of fire<br />

suppression systems.<br />

3. Furthermore, fire detection and a<br />

fixed fire suppression system shall<br />

be installed in the area, room, or<br />

zone.”<br />

Guidance IX of the NRC Information<br />

Notice 84-094 lists the minimum safe<br />

shutdown monitoring parameters<br />

accepted by the NRC [NRC Information<br />

Notice, 1984].<br />

NUREG-1852 presents the feasibility<br />

and reliability criteria [NUREG,<br />

2007] accepted by the NRC in the<br />

event that Operator Manual Actions<br />

(OMAs) are used to perform post-fire<br />

safe shutdown.<br />

The above fire protection regulations<br />

provide the parameters relevant<br />

to safe shutdown capabilities and<br />

fire protection. We compared these<br />

parameters with those of the nuclear<br />

power plant in our case study to<br />

identify problems associated with<br />

safe shutdown capabilities and fire protection.<br />

However, this is an enormous<br />

and complex task. Thus, we developed<br />

an innovative approach to achieve this<br />

using knowledge management in<br />

conjunction with TRIZ.<br />

3 Methodology<br />

This study sought to improve the safe<br />

shutdown performance of nuclear<br />

power plants in the event of fire.<br />

Knowledge management was first<br />

used to identify the factors essential<br />

to safe shutdown. We then sought<br />

to identify the factors that are not<br />

adequately addressed in US nuclear<br />

power regulations. Finally, TRIZ was<br />

used to guide the formulation of<br />

recommendations aimed at overcoming<br />

current regulatory shortcomings.<br />

3.1 Knowledge management<br />

and construction of database<br />

Knowledge management was organized<br />

into the following phases to<br />

define core knowledge and construct a<br />

database for research [Rosner et al.,<br />

1998].<br />

Phase 1: Progress from the macroscopic<br />

system level to the microscopic<br />

equipment level.<br />

Phase 2: Identify wiring associated<br />

with post-fire safe-shutdown.<br />

Phase 3: Conduct post-fire safe-shutdown<br />

circuit analysis [Debowski,<br />

2007].<br />

Phase 4: Establish post-fire hot shutdown<br />

path based on APP.R.<br />

Phase 5: Construct a distribution of<br />

post-fire safe hot shutdowns procedures<br />

throughout the plant.<br />

Phase 6: Establish basic fire prevention<br />

database [National Fire Protection<br />

Association, 2001].<br />

3.2 Application of TRIZ to<br />

improve safe shutdown<br />

system<br />

TRIZ is a highly reliable problemsolving<br />

method, which was developed<br />

by Altshuller et al. in his review of over<br />

300,000 patents between 1946 and<br />

1985 [Altshuller, 1999]. TRIZ is based<br />

on the concept of abstraction, taking<br />

an algorithmic approach to the invention<br />

of new systems and the refinement<br />

of old systems [Mann, 2007].<br />

In this study, we combined<br />

knowledge management and TRIZ<br />

in the development of a novel<br />

method by which to improve safe<br />

shutdown procedures, as follows<br />

(comp. Figure 1):<br />

1. Collect data pertaining to<br />

current conditions and existing<br />

designs.<br />

2. Formulate standards and definitions<br />

based on existing regulations<br />

related to post-fire safe<br />

shutdown.<br />

3.1. Define and clarify issues. If<br />

sufficient data is available, proceed<br />

to Step 4; otherwise, proceed<br />

to Step 3.2.<br />

3.2. Search available data and current<br />

regulations for designs that could<br />

be improved through knowledge<br />

management. Compare results<br />

with the safety conditions stipulated<br />

in current regulations, and<br />

then conduct enhancement<br />

analysis based on the following<br />

knowledge management techniques:<br />

(1) establish operating<br />

standards; (2) identify interdependent<br />

relationships between<br />

existing systems; (3) organize<br />

operational procedures; (4) set<br />

safe shutdown function codes;<br />

(5) establish safe shutdown path<br />

combinations; (6) compare results<br />

with regulation requirements;<br />

(7) identify all devices associated<br />

with post-fire safe shutdown<br />

(8) set operating status parameters;<br />

(9) compare results with<br />

corresponding wire/circuit design<br />

data of original equipment;<br />

(10) identify wires/circuits associated<br />

with post-fire safe shutdown;<br />

(11) conduct wire/circuit failure<br />

analysis; (12) compile results of<br />

wire/circuit analysis in the form<br />

of a database; (13) establish wire/<br />

circuit paths in fire zones. If<br />

level-by-level comparisons show<br />

that the existing system complies<br />

with regulations, then proceed<br />

to Step 6.<br />

4. Search through database of<br />

existing system for instances of<br />

mismatch with regulations. If the<br />

database does not meet safety<br />

requirements, then return to<br />

Step 1. If the database meets<br />

safety requirements, then perform<br />

an assessment of ...<br />

5. Determine whether non-compliant<br />

systems affect safe shutdown<br />

capabilities.<br />

Operation and New Build<br />

The Application of Knowledge Management and TRIZ for solving the Safe Shutdown Capability in Case of Fire Alarms in Nuclear Power Plants ı Chia-Nan Wang, Hsin-Po Chen, Ming-Hsien Hsueh and Fong-Li Chin


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

6. If the current safe shutdown<br />

capabilities meet or surpass those<br />

stipulated in the regulations, then<br />

proceed to Step 8. If the current<br />

safe shutdown capabilities do<br />

not meet those stipulated in the<br />

regulations, then proceed to<br />

Step 7.<br />

7. Use TRIZ to search for improvement<br />

methods, while taking into<br />

account construction costs and<br />

probable benefits.<br />

8. If the current status of the nuclear<br />

power plant complies with the<br />

basic safety conditions stipulated<br />

in the regulations, then it is<br />

assumed that the plant possesses<br />

satisfactory safe shutdown capability.<br />

4 Empirical results<br />

4.1 Application of knowledge<br />

management<br />

We selected a nuclear power plant for<br />

use as a case study. Fire compartments<br />

were drawn up according to the floor<br />

plan and final safety analysis report<br />

(FSAR) (Table 1). Most nuclear power<br />

plants include the following: containment<br />

or drywell building, reactor<br />

(auxiliary) building, turbine building,<br />

intake structure (screenhouse), fuel<br />

building, diesel generator building. In<br />

principle, if an area is enclosed by<br />

fire-shielding concrete walls, then<br />

smaller fire zones can be drawn up<br />

within the larger fire zone in order to<br />

differentiate between similar paths. In<br />

this case, the original fire compartment<br />

C101 includes numerous rooms.<br />

ESF 4.16KV SWGR ROOM A was designated<br />

fire compartment 5 in order to<br />

re-partition the space according to<br />

their function.<br />

Phase 1: Progress from the macroscopic<br />

system level to the microscopic<br />

equipment level.<br />

Step 1: Define the scope of the<br />

post-fire safe shutdown capacity.<br />

Shutdown objectives include the<br />

following: 1. reactivity control;<br />

2. reactor coolant makeup; 3. reactor<br />

heat removal; 4. process monitoring;<br />

5. supporting functions; 6. achieve hot<br />

Unit<br />

FL<br />

No.<br />

FL<br />

Code<br />

Factory<br />

building<br />

| | Tab. 1.<br />

Examples of partitioning fire compartment in nuclear power plant.<br />

| | Fig. 1.<br />

Application of knowledge management and TRIZ to improve post-fire safe shutdown performance.<br />

standby status and maintain systems<br />

required to (i) prevent fire damage,<br />

(ii) enable the power unit to last<br />

through hot standby status for over<br />

72 hours, and (iii) receive power<br />

from emergency power system;<br />

7. achieve cold shutdown status<br />

and maintain systems required to<br />

prevent fire damage. The above<br />

objectives do not cover the following:<br />

(1) seismic category I criteria,<br />

(2) single failure criteria, or (3) other<br />

plant accidents.<br />

Step 2: Define the core knowledge<br />

parameters of post-fire safe shutdown<br />

capacity.<br />

1) Establish map of interdependence<br />

among systems employed in<br />

post-fire safe shutdown. 2) Define<br />

operating procedures of post-fire safe<br />

shutdown systems and construct<br />

operational flowchart. 3) Define<br />

parameters of post-fire safe shutdown<br />

functions and construct function code<br />

list. 4) Identify function code combinations<br />

required for post-fire safe<br />

shutdown path and construct path<br />

combination table.<br />

Step 3: Refer to existing regulations<br />

NEI-0001 and RG1.189 of<br />

US–NRC to confirm that the post-fire<br />

safe shutdown and wire/circuit<br />

analysis methods are acceptable.<br />

First step: Determine Regulatory<br />

Requirements<br />

Space<br />

FL Name<br />

1 1 C101 CTRL 80' ESSENTIAL CHILLER ROOM A<br />

1 2 C101 CTRL 80' ESF 4.16KV SWGR ROOM A<br />

1 3 C101 CTRL 80' ESF SWGR ROOM A<br />

1 4 C1<strong>02</strong> CTRL 80' ESSENTIAL CHILLER ROOM B<br />

1 5 C1<strong>02</strong> CTRL 80' ESF 4.16KV SWGR ROOM B<br />

The primary regulations include<br />

10 CFR 50 Appendix A, General Criterion<br />

3, and 10 CFR 50 Appendix R.<br />

Second step: Determine SSD<br />

Functions, Systems, and Path<br />

This is meant to ensure that any<br />

single fire within any fire area in the<br />

nuclear power plant does not lead to<br />

incidents such as furnace core meltdown,<br />

loss of reactor cooling water, or<br />

damage to the primary containment<br />

structure. To achieve this objective,<br />

the safe shutdown functions of the<br />

reactor must first be confirmed and<br />

the existing system equipment and<br />

pipelines in the plant analyzed and<br />

combined to form a safe shutdown<br />

path as well as achieve and maintain<br />

the safe shutdown status of the power<br />

unit.<br />

Third step: Select Equipment<br />

Required for Post-Fire Safe shutdown<br />

This equipment is used for post-fire<br />

safe shutdown or to serve as a backup<br />

in the event of fire-induced malfunctions.<br />

Fourth step: Select Wires/Circuits<br />

for Post-Fire Safe shutdown<br />

These wires/circuits are used for<br />

post-fire safe shutdown or to serve as a<br />

backup in the event of fire-induced<br />

malfunctions<br />

Below are the basic assumptions<br />

used in the analysis of post-fire safe<br />

shutdown capacity:<br />

1. Only one fire occurs in the plant at<br />

any one time.<br />

2. In the event of loss of external<br />

power due to fire, systems can<br />

provide backup power for at least<br />

72 hours.<br />

3. The only equipment or system<br />

malfunctions are associated<br />

directly with the fire.<br />

4. After the safe shutdown of the<br />

power unit, there are no additional<br />

accidents due to plant design<br />

OPERATION AND NEW BUILD 97<br />

Operation and New Build<br />

The Application of Knowledge Management and TRIZ for solving the Safe Shutdown Capability in Case of Fire Alarms in Nuclear Power Plants ı Chia-Nan Wang, Hsin-Po Chen, Ming-Hsien Hsueh and Fong-Li Chin


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

OPERATION AND NEW BUILD 98<br />

Drawing<br />

No.<br />

including (1) loss-of-coolant accidents<br />

(LOCA), (2) main steam line<br />

breaks (MSLB), (3) steam generator<br />

tube ruptures (SGTR), or (4)<br />

control rod ejection accidents<br />

(REA.)<br />

5. Any wires or equipment in the area<br />

of a fire that are not protected by<br />

fire wrap are burned, unless the<br />

results fire disaster analysis prove<br />

otherwise.<br />

6. Fire-induced wire/circuit damage<br />

can lead to open circuits, short<br />

circuits, hot shorts, and shorts to<br />

ground.<br />

7. The valves, pipelines, tanks, or<br />

incombustible instrument wires<br />

affected by the fire do not cause<br />

damage to the pressure boundary.<br />

8. Despite fire damage to instruments,<br />

the pressure boundaries<br />

of fluids within them are not<br />

damaged.<br />

9. Motor-operated valves do not malfunction<br />

due to fire damage to<br />

power wires, but they may malfunction<br />

following fire damage to<br />

control circuits.<br />

10. During post-fire safe shutdown,<br />

power units may be controlled<br />

manually using existing equipment,<br />

as long as the fire does not<br />

directly hinder such operations.<br />

The scope of the core knowledge<br />

relating to post-fire safe shutdown<br />

capacity can be clearly defined and<br />

verified based on the analytical<br />

methods proposed in NEI 00-01 Rev. 2<br />

and the target performance of safe<br />

shutdown capacity.<br />

Step 4: Establish inventory of<br />

post-fire safe shutdown equipment.<br />

Determine the specifications of<br />

post-fire safe shutdown equipment<br />

(Table 2): 1. attributes, 2. operating<br />

status, and 3. path parameters [NFPA,<br />

2001].<br />

Function Description<br />

Old System<br />

Code<br />

SSD<br />

Code<br />

1 RCS BB B1/B2<br />

2 RCS-ACCUM ISO BH B1/B2<br />

3 CVCS HHSI BG B5/B6<br />

4 CVCS HHSI SUP BG BS56<br />

5 SIS HHSI BH B7/B8<br />

6 CVCS RCP BG C5/C6<br />

| | Tab. 2.<br />

Post-fire safe shutdown system parameters for case study.<br />

Phase 2: Identify wire/circuits<br />

associated with post-fire alarm safe<br />

shutdown.<br />

Step 1: Identify wires and circuits<br />

associated used with post-fire safe<br />

shutdown equipment.<br />

Using the original design data of<br />

the plant, list every power wire and<br />

control wire associated with the<br />

post-fire safe shutdown equipment.<br />

Step 2: Determine the specifications<br />

of all wire/circuits associated<br />

with post-fire safe shutdown. Set the<br />

parameters of operating status,<br />

equipment attributes, and the safe<br />

shutdown paths to which they belong.<br />

Step 3: Refer to the existing database,<br />

control wiring diagram (CWD),<br />

and control logic diagram (CLD) to<br />

identify the control wires associated<br />

with each piece of equipment.<br />

Step 4: Compile an inventory of<br />

wires associated with post-fire safe<br />

shutdown (NEI, 2009).<br />

A series post-fire safe shutdown<br />

path (Code: HSD-P1):<br />

(A1+A3)+(B1+B3+B5+B7+B9)+<br />

(D1+E1+F1+G1+H1+I1+J1+K1+<br />

L1+M1+N1+P1+S1+U1+V1+<br />

W1+X1+Y1.)<br />

B series post-fire safe shutdown<br />

path (Code: HSD-P2):<br />

(A2+A4)+(B2+B4+B6+B8+B10)+<br />

(D2+E2+F2+G2+H2+I2+J2+K2+<br />

L2+M2+N2+P2+S2+U2+V2+<br />

W2+X2+Y2)<br />

Taking the plant from operating<br />

to hot shutdown requires that the<br />

equipment listed above be operational.<br />

These devices must also be<br />

included in independent paths<br />

HSD-P2 or HSD-P1.<br />

Example of system parameters<br />

(Table 2) and shutdown path: The<br />

power for the motor driven auxiliary<br />

feed water pump (A-1M-AL-P017) in<br />

auxiliary feed water system of Series A<br />

(system parameter B3) is supplied by<br />

Class 1E 4.16kV Bus A-1E-PB-S01 (PB<br />

system). In post-fire safe shutdown<br />

operation mode, this bus is powered<br />

by the emergency diesel generator in<br />

Series A (system parameter D1). Thus,<br />

a supply of lubricating oil and a fuel<br />

(KJ system) must be available for the<br />

emergency diesel generator. At the<br />

same time, it is essential that the 125V<br />

DC electrical system (PK system)<br />

provide power to the control panel<br />

of the emergency diesel generator<br />

A-1J-ZD-P001. The emergency diesel<br />

generator is uses a jacket water-cooler<br />

A-1M-KJ-X072 running off of a<br />

seawater system (EF system); the<br />

power for the seawater pump A-1M-<br />

EF-P103, P104 is provided by the<br />

4.16kV bus A-1E-PB-S01 (PB system.)<br />

This is an example of the analysis used<br />

to establish the interdependence of<br />

systems within a given post-fire safe<br />

shutdown path.<br />

Phase 3: Establish an inventory of<br />

wire/circuits associated with post-fire<br />

safe shutdown.<br />

Step 1: Use the wire/circuit inventory<br />

established in previous phase to<br />

conduct effect analysis of fire-induced<br />

wire/circuit failures. Analyze fire- induced<br />

circuit failures (power, control,<br />

instrument) associated with each piece<br />

of equipment, based on inventory of<br />

equipment used in post-fire safe shutdown.<br />

These wire/circuits can be<br />

divided into two categories: those<br />

necessary to post-fire hot shutdown<br />

and those necessary to post-fire safe<br />

shutdown. Single-line diagrams, CLDs,<br />

and CWDs of post-fire safe shutdown<br />

equipment in the original design are<br />

used to investigate fire-induced circuit<br />

failures, as follows:<br />

(1) Categorization of wires required<br />

for post-fire hot shutdown:<br />

a. Power and control wires required<br />

for manual operation of equipment<br />

used in post-fire hot shutdowns<br />

b. Power and signal wires for instruments<br />

used in process monitoring<br />

during post-fire hot shutdown<br />

c. Wires that could cause the malfunction<br />

(through fire-induced<br />

circuit failure) of equipment required<br />

for post-fire hot shutdowns<br />

d. Wires that could cause the malfunction<br />

of components (through<br />

fire-induced circuit failure) in<br />

high/low pressure system<br />

(2) Categorization of wires required<br />

for post-fire safe shutdown:<br />

a. Power and control wires required<br />

for manual operation of equipment<br />

used in post-fire cold shutdowns<br />

b. Wires that could cause the malfunction<br />

(through fire-induced<br />

circuit failure) of equipment required<br />

for cold shutdowns<br />

c. Wires that could cause the malfunction<br />

of components crucial to<br />

shutdowns (through fire-induced<br />

circuit failure)<br />

Fire-induced circuit-failure parameters<br />

were established as follows:<br />

1) fire-induced circuit-failure equipment,<br />

2) operating status parameters,<br />

3) fire-induced circuit-failure parameters,<br />

and 4) wire/circuit attribute<br />

parameters.<br />

Step 2: Use the circuit-failure<br />

parameters to construct a table for the<br />

analysis of circuits used in post-fire<br />

safe shutdown.<br />

Effect analysis of fire-induced<br />

circuit failures associated with the<br />

post-fire safe shutdown equipment,<br />

including open circuits, short circuits,<br />

hot shorts, and shorts to ground (445<br />

items in total). This analysis produced<br />

5,149 results.<br />

Operation and New Build<br />

The Application of Knowledge Management and TRIZ for solving the Safe Shutdown Capability in Case of Fire Alarms in Nuclear Power Plants ı Chia-Nan Wang, Hsin-Po Chen, Ming-Hsien Hsueh and Fong-Li Chin


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

Cable No.<br />

SSD<br />

Code<br />

SSD Equipment<br />

No.<br />

| | Tab. 3.<br />

Examples of post-fire safe shutdown cable paths.<br />

After referring to the parameters<br />

associated with post-fire safe shutdown<br />

equipment in the previous step,<br />

the fire-induced circuit-failure effect<br />

parameters and wire/circuit attributes<br />

were compiled into a post-fire<br />

safe shutdown circuit analysis table.<br />

Four types of parameter were<br />

required: 1) fire-induced circuitfailure<br />

equipment, 2) operating status<br />

parameters, 3) fire-induced circuitfailure<br />

parameters, and 4) wire/<br />

circuit attribute parameters.<br />

Step 3: The regulations stipulate<br />

special requirements for the wiring<br />

involved in hot shutdowns; therefore,<br />

the scope of the core knowledge was<br />

defined as the wires associated with<br />

post-fire hot shutdowns.<br />

Step 4: We establish an inventory<br />

of the wires involved in post-fire safe<br />

hot shutdown.<br />

Phase 4: Establish a path associated<br />

with post-fire hot shutdown for<br />

use as a reference based on the special<br />

requirements in APP.R with regard to<br />

wires associated with hot shutdown.<br />

Step 1: Define the scope of core<br />

knowledge and the wires associated<br />

with post-fire hot shutdown.<br />

Step 2: Set the relevant wire/<br />

circuit parameters, equipment operating<br />

status parameters, equipment<br />

attribute parameters, and safe shutdown<br />

path parameters.<br />

Step 3: Refer to the existing wire/<br />

circuit layout program SETROUTE in<br />

the original design to derive the circuit<br />

layout. The fire zones will need to be<br />

updated, as the original layout<br />

program uses the old fire zones. To<br />

facilitate analysis, the fire zones,<br />

equipment specifications, safe shutdown<br />

paths, and operating status<br />

parameters must be added to the database<br />

of the wire/circuit layout.<br />

Step 4: Establish an inventory of<br />

wire/circuit paths involved in post-fire<br />

safe shutdown.<br />

Step 5: Establish the post-fire<br />

alarm safe hot shutdown path form<br />

(Table 3). Compile a report of wire/<br />

circuit paths involved in post-fire safe<br />

hot shutdown. The nuclear power<br />

plant in the case study has two power<br />

units. Unit 1 contains 1,189 wires and<br />

17,379 items, whereas Unit 2 contains<br />

SSD<br />

Path<br />

SSD Cable<br />

Type<br />

1,184 wires and 17,233 items. Thus,<br />

there are 2,373 wires associated with<br />

post-fire safe hot shutdown. The<br />

organization of the report is based on<br />

the number system used for the safe<br />

shutdown equipment, the attribute<br />

categorization of the wires, their<br />

origin and destination, the numbering<br />

of the wire/circuit raceways, and the<br />

fire zones through which they pass.<br />

Phase 5: Construct the distribution<br />

of post-fire safe hot shutdowns<br />

throughout the entire plant.<br />

Step 1: Define the scope of the core<br />

knowledge and the post-fire safe hot<br />

shutdown path.<br />

Step 2: Set the fire zones to their<br />

corresponding parameters.<br />

Step 3: Based on the wire/circuit<br />

layout program, identify the fire zones<br />

through which each wire passes.<br />

Step 4: Establish the distribution<br />

of the post-fire hot-shutdown function<br />

codes and replot the post-fire hotshutdown<br />

tray routing diagram in<br />

order to obtain an overview of the safe<br />

hot shutdown capacity throughout<br />

the entire plant.<br />

Example: Series A is presented in<br />

red and series B in green. The safe<br />

shutdown cable path in the original<br />

SETROUTE and corresponding function<br />

code are used to obtain the safe<br />

shutdown path and function code of<br />

each fire containment zone (Table 4).<br />

Phase 6: Establish a database of<br />

items pertaining to basic fire prevention.<br />

Basic fire prevention includes a<br />

wide range of items: (1) basic data of<br />

fire zones, (2) firefighting equipment<br />

in fire zones, (3) fire dampers, (4) fire<br />

doors, (5) combustion load of fire<br />

zones, (6) list of fire zones adjacent to<br />

each fire zone (7), inventory of heat<br />

generated by all combustible items.<br />

4.2 Application of TRIZ<br />

The proposed knowledge management<br />

approach revealed that fire<br />

compartments 1 and 17 do not comply<br />

with some regulations [10 CFR 50.48<br />

APP.R]. Specifically, Wires involved in<br />

post-fire safe hot shutdown must not<br />

pass through the same fire compartment<br />

without the implementation of<br />

suitable fire protection measures. The<br />

FROM No. Raceway No. FZ<br />

B1EEFHCC8SA H2 B-EF-HV203 HSD-P2 HSD-S 1JZJP061E-F 1 B1EZJG2TSRH 20<br />

B1EEFHCC8SA H2 B-EF-HV203 HSD-P2 HSD-S 1JZJP061E-F 2 B1EZJG2TUAG 20<br />

B1EEFHCC8SA H2 B-EF-HV203 HSD-P2 HSD-S 1JZJP061E-F 3 B1EZJG2TUAF 20<br />

FL FL No. HSD Path No. SSD Path<br />

1 C101 D1 HSD-P1<br />

1 C101 H1 HSD-P1<br />

1 C101 I2 HSD-P2<br />

1 C101 K2 HSD-P2<br />

| | Tab. 4.<br />

Example distribution list of fire alarm safe hot shutdown function codes.<br />

| | Fig. 2.<br />

Qualitative analysis model for identification<br />

of problem.<br />

| | Fig. 3.<br />

Standard solutions for eliminating harmful<br />

effects of fire.<br />

passage of series A and B wires<br />

through FZ 1 and FZ 17 renders this<br />

area vulnerable to fire damage [Hua<br />

and Yang, 2006]. The structure of this<br />

problem is modeled in Figure 2.<br />

Figure 3 presents a qualitative<br />

field model illustrating the association<br />

between completeness and damage,<br />

revealing the first problems to be<br />

eliminated or controlled in a standard<br />

solution.<br />

In this case, the designers used<br />

XPE/Cl.S.PE cables with heat<br />

resistance of 90 °C. Their Q value<br />

(Bench-Scale HRR per Unit Floor<br />

Area) is 204 kW/m 2 , which means<br />

that they are classified as safe, even in<br />

OPERATION AND NEW BUILD 99<br />

Operation and New Build<br />

The Application of Knowledge Management and TRIZ for solving the Safe Shutdown Capability in Case of Fire Alarms in Nuclear Power Plants ı Chia-Nan Wang, Hsin-Po Chen, Ming-Hsien Hsueh and Fong-Li Chin


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

OPERATION AND NEW BUILD 100<br />

| | Fig. 4.<br />

Parameter attribute problem model for fire damage to the cable.<br />

the event of fire; i.e., they have a<br />

high ignition point and low release<br />

of heat. The conductivity of the cable<br />

helps to maintain its structural integrity<br />

[NUREG, 2010]. The first<br />

physical contradiction appears when<br />

the temperature exceeds 100 °C.<br />

There are four steps that can be taken<br />

to combat this: spatial separation,<br />

temporal separation, condition separation,<br />

and separation of system<br />

levels. These are used to perform<br />

separation of fire areas, cable burn<br />

time, burning conditions, and safe<br />

shutdown system levels (Figure 4).<br />

All cables must remain reliable<br />

along their entire length in order to<br />

ensure a safe shutdown. The fact that<br />

fire damage can compromise<br />

reli ability leads to the second technical<br />

contradiction.<br />

We constructed a 39X39 contradiction<br />

matrix to be compared with<br />

the 40 Inventive Principles based on<br />

the problem model established on<br />

structural attributes and parameter<br />

attributes. Comparison of temperature<br />

and reliability resulted in the<br />

selection of the following inventive<br />

principles:<br />

# 3: Local quality<br />

#10: Preliminary action<br />

#19: Periodic action<br />

#35: Parameter changes<br />

A panel of experts decided to disregard<br />

Principle #19. Principle #35<br />

was not applicable because the cables<br />

had already been laid. Principles #3<br />

and #10 were implemented for<br />

reasons outlined in the following:<br />

Inventive principle #3 (local quality):<br />

3a. Change an object’s structure from<br />

uniform to non-uniform, change<br />

an external environment (or<br />

external influence) from uniform<br />

to non-uniform.<br />

3b. Make each part of an object<br />

function in conditions most<br />

suitable to its operation.<br />

3c. Make each part of an object fulfill a<br />

different and useful function.<br />

Improvement requirements and<br />

feasible methods<br />

(1) Cables from Series A and B should<br />

be separated by at least 20 feet.<br />

(2) Built-in discrete fire detection<br />

systems should be included in all<br />

areas. In the original design, FZ 1<br />

and FZ 17 each had one feedback<br />

system; however, they are now<br />

segmented into a feedback loop for<br />

each area [Generic Letters, 1983].<br />

(3) Install close-spaced, open-head<br />

sprinklers. According to GL 83-33,<br />

Position 2: “In many plant areas,<br />

the erection of physical barriers<br />

between redundant shutdown<br />

systems is precluded by the location<br />

of cable trays, HVAC ducts and<br />

other plant features. In such situations,<br />

the staff has accepted, in<br />

concept, the use of an automatic<br />

fire suppression system which<br />

No.<br />

Cable<br />

No.<br />

SSD<br />

Code<br />

Cable<br />

Code<br />

SSD<br />

Equipment No.<br />

SSD<br />

Path<br />

SSD<br />

Cable Type<br />

Raceway<br />

No.<br />

Rway<br />

Code<br />

1 B1EAPHBC2XA K2 EE6 B-AP-LT201 HSD-P2 HSD-S B1EZJF4TXBA WC<br />

2 B1EBNHAC2XA K2 EE6 B-BNLT961 HSD-P2 HSD-S B1EZJF4TXBA WC<br />

3 B1EEFHAC2XA H2 EE6 B-EF-PT201 HSD-P2 HSD-S B1EZJF4TXBA WC<br />

4 B1EEFHAC2XB H2 EE6 B-EF-PT2<strong>02</strong> HSD-P2 HSD-S B1EZJF4TXBA WC<br />

5 B1EEFHCC3EA H2 71M3 B-EF-P105 HSD-P2 HSD-S B1EZJF4TEBA SC<br />

6 B1EEFHCC3EB H2 71M B-EF-P105 HSD-P2 HSD-S B1EZJF4TEBA SC<br />

7 B1EEFHCC4EA H2 71M3 B-EF-P106 HSD-P2 HSD-S B1EZJF4TEBA SC<br />

8 B1EKJHBC3LA D2 938 B-KJ-P147 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

9 B1EKJHBC4LA D2 938 B-KJ-P148 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

10 BIEPGHHCEHH E2 91I3 B-1E-PG-S01-07 HSD-P2 HSD-S B1EZJF4TIBA SA<br />

11 B1EPGHHCEHJ E2 91I3 B-1E-PG-S01-07 HSD-P2 HSD-S B1EZJF4TIBA SA<br />

12 B1EEFHBCBSB H2 939 B-EF-HV230 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

13 B1EEFHBCBSD H2 939 B-EF-HV230 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

14 B1EEFHBCBSE H2 939 B-EF-HV230 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

15 B1EEFHBCJSA H2 C77 B-EF-HV206 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

16 B1EEFHCC8SA H2 C27 B-EF-HV203 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

17 B1EEFHCC8SB H2 C27 B-EF-HV203 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

18 B1EEFHCC8SC H2 C27 B-EF-HV203 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

19 B1EEFHCC9SA H2 C27 B-EF-HV222 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

20 B1EEFHCC9SB H2 C27 B-EF-HV222 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

21 B1EEFHCC9SC H2 C27 B-EF-HV222 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

22 B1EEFHCCASA H2 C77 B-EF-HV221 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

| | Tab. 5.<br />

Parameter attribute problem model for fire damage to the cable.<br />

Operation and New Build<br />

The Application of Knowledge Management and TRIZ for solving the Safe Shutdown Capability in Case of Fire Alarms in Nuclear Power Plants ı Chia-Nan Wang, Hsin-Po Chen, Ming-Hsien Hsueh and Fong-Li Chin


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

Advertisement<br />

discharges a “water curtain” across<br />

the boundary areas separating the<br />

redundant systems. The staff's<br />

present position is that such systems<br />

should feature close-spaced,<br />

open-head sprinklers with water<br />

discharge initiated by tripping a<br />

deluge valve activated by crosszoned<br />

smoke detectors.” Installation<br />

of a “water curtain” partition<br />

within the fire compartment<br />

ensured that both paths were safe<br />

for post-fire hot shutdown.<br />

(4) Install fire separation walls. Specifications:<br />

1. Fire resistance of<br />

3 hours. 2. Extending from wall to<br />

wall and from floor to ceiling.<br />

3. Fire door with a 3-hour rating to<br />

facilitate access by personnel.<br />

4. Air ducts that pass through the<br />

fire separation wall. A fire damper<br />

with a 3-hour rating must be<br />

installed within the section that<br />

passes through the fire separation<br />

wall. 5. A sleeve must be added to<br />

all piping that penetrates the fire<br />

separation wall. The sleeve must<br />

be sealed using fire-resistant<br />

material with a rating of 3 h. 6. The<br />

cable net passing through the fire<br />

separation wall must be filled with<br />

fire-resistant materials with a<br />

rating of 3 h [Generic Letters,<br />

1986]. The post-fire hot shutdown<br />

cable for FZ 17 runs through an<br />

aisle; therefore, fire separation<br />

walls are feasible only in FZ 1.<br />

The definitions and improvement<br />

plans associated with inventive<br />

principle #10 are as follows:<br />

10a: Perform all modifications in<br />

advance. Rearrange cables (relatively<br />

low cost.)<br />

10b: Install items or systems in<br />

advance to ensure that they are<br />

ready when and where that may<br />

be.<br />

FZ 1 contains mostly Series A cables<br />

as well as 22 Series B cables. The<br />

post-fire hot shutdown cable list<br />

( Table 5) revealed that 11 of the<br />

cables (number 1-11) can be re-laid<br />

along new paths, such that only 11<br />

cables (number 12-22) from Series B<br />

remain within FZ 1. At this point 10b<br />

No.<br />

SSD<br />

Equipment No.<br />

Status<br />

9. Symposium zur<br />

Endlagerung<br />

radioaktiver Abfälle<br />

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Wege zum G2-Gebinde<br />

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• KFK – Herausforderung aus Sicht eines<br />

EVUs<br />

• Endlager Konrad – Baufortschritt und<br />

Stand der sicherheitstechnischen<br />

Überprüfung<br />

• Aspekte der Endlagerungsbedingungen<br />

• Entsorgung von Altabfällen<br />

• Vorgehensweisen bei der stofflichen<br />

Produktkontrolle<br />

• Optimierte Prüfung von Antragsunterlagen<br />

Das detaillierte Programm finden Sie in Kürze<br />

unter: www.tuev-nord.de/tk-era<br />

Organisation:<br />

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E-Mail: mlangmann@tuev-nord.de<br />

Telefon: 040 8557-2046<br />

OPERATION AND NEW BUILD 101<br />

1 B-EF-HV203 ON<br />

2 B-EF-HV206 ON<br />

3 B-EF-HV221 ON<br />

4 B-EF-HV222 OFF<br />

5 B-EF-HV230 OFF<br />

| | Tab. 6.<br />

Valve states in hot shutdown mode.<br />

Operation and New Build<br />

The Application of Knowledge Management and TRIZ for solving the Safe Shutdown Capability in Case of Fire Alarms in Nuclear Power Plants ı Chia-Nan Wang, Hsin-Po Chen, Ming-Hsien Hsueh and Fong-Li Chin


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

OPERATION AND NEW BUILD 1<strong>02</strong><br />

can be used for OMA for manual<br />

disconnection or operations.<br />

To prevent equipment malfunction<br />

due to fire-induced cable damage, a<br />

fire alarm in FZ 1W signals the control<br />

room to initiate the first safe shutdown<br />

path using Series A cables.<br />

Similarly, a fire alarm in FZ 1E signals<br />

the control room to initiate the second<br />

safe shutdown path using Series B<br />

cables. On-duty staff must take the<br />

actions presented in Table 6.<br />

FZ 17 contains mainly Series B<br />

cables as well as 11 Series A cables.<br />

The post-fire hot shutdown cable list<br />

(Table 7) revealed there is no way to<br />

re-route the cable paths. At this point<br />

10b can be used for OMA for manual<br />

disconnection or operations.<br />

A fire alarm in FZ 17W signals the<br />

control room to initiate the first safe<br />

No.<br />

| | Fig. 5.<br />

Conformity to regulations in chart form.<br />

No. Cable No. SSD<br />

Code<br />

SSD<br />

Equipment No.<br />

Status<br />

1 B-EF-HV203 ON<br />

2 B-EF-HV206 ON<br />

3 B-EF-HV221 ON<br />

4 B-EF-HV222 OFF<br />

5 B-EF-HV230 OFF<br />

| | Tab. 8.<br />

Valve states in hot shutdown mode.<br />

Cable<br />

Code<br />

SSD Equipment<br />

No.<br />

SSD<br />

Path<br />

shutdown path using Series A cables.<br />

A fire alarm in FZ 17E signals the<br />

control room to initiate the second<br />

safe shutdown path using B cables.<br />

On-duty staff must take the actions<br />

presented in Table 8.<br />

The application of TRIZ requires<br />

that the following conditions be<br />

satisfied: At least one of the wire series<br />

has avoided fire damage. For the sake<br />

of simplicity, we adopted two inventive<br />

principles: finding local properties<br />

and taking preliminary actions.<br />

Nuclear power regulation 10 CFR<br />

50.48 APP.R stipulates that any wiring<br />

essential to post-fire hot shutdowns<br />

that passes through the same fire zone<br />

require sufficient shielding to protect<br />

them from fire for at least three h.<br />

They must also be separated at least<br />

20 ft, and automatic fire detection<br />

and extinguishing systems must be<br />

installed in the fire zone in question.<br />

All wiring is expected to comply<br />

with these regulations; however, prior<br />

to modifications based on the proposed<br />

method, 22 of the wires in<br />

Series B were non-compliant. This<br />

situation could not be foreseen without<br />

integration of 850,000 pieces of<br />

path data via knowledge management.<br />

Among the 22 wires, 11 were<br />

re-laid and within a fire compartment,<br />

thereby reducing the number of<br />

non-compliant wires to 11. According<br />

to the principle of preliminary action,<br />

the remaining 11 wires were deemed<br />

not to affect post-fire hot shutdown<br />

performance; therefore, even these 11<br />

wires can be said to comply with<br />

regulations.<br />

Regulations stipulate that the<br />

control room or emergency control<br />

station be equipped with a series of<br />

hot shutdown systems capable of<br />

maintaining hot shutdown conditions<br />

in the event of a fire in Fire Zones 1<br />

and/or 17.<br />

SSD<br />

Cable Type<br />

Raceway<br />

No.<br />

1 B1EEFHBCBSB H2 939 B-EF-HV230 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

2 B1EEFHBCBSD H2 939 B-EF-HV230 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

3 B1EEFHBCBSE H2 939 B-EF-HV230 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

4 B1EEFHBCJSA H2 C77 B-EF-HV206 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

5 B1EEFHCC8SA H2 C27 B-EF-HV203 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

6 B1EEFHCC8SB H2 C27 B-EF-HV203 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

7 B1EEFHCC8SC H2 C27 B-EF-HV203 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

8 B1EEFHCC9SA H2 C27 B-EF-HV222 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

9 B1EEFHCC9SB H2 C27 B-EF-HV222 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

10 B1EEFHCC9SC H2 C27 B-EF-HV222 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

11 B1EEFHCCASA H2 C77 B-EF-HV221 HSD-P2 HSD-S B1EZJF4TPBA SE<br />

| | Tab. 7.<br />

Series A cables in fire compartment 17 for safe hot shutdown.<br />

Rway<br />

Code<br />

Fire compartments capable of<br />

withstanding fire for three hours were<br />

installed between post-fire safe hot<br />

shutdown wires. The wires were<br />

horizontally separated by at least 20 ft<br />

and automatic fire detection and<br />

extinguishing systems were installed.<br />

Following these improvements in Fire<br />

Zones 1 and 17, the post-fire safe hot<br />

shutdown wires were in full compliance<br />

with regulations (Figure 5).<br />

Number of cables that do not<br />

comply with regulations ≠ Estimated<br />

number of cables that do not comply<br />

with regulations = “Do not comply<br />

with regulations”<br />

Number of cables that do not<br />

comply with regulations = Estimated<br />

number of cables that do not comply<br />

with regulations = “Comply with<br />

regulations”<br />

Number of non-complaint cables in<br />

case study nuclear power plant = 0<br />

5 Conclusions<br />

This study applied TRIZ and<br />

knowledge management to an actual<br />

nuclear power plant in order to<br />

bring the facility up to regulatory<br />

minimums. Problems were identified<br />

using hierarchy analysis in conjunction<br />

with knowledge management for<br />

the construction of a database. We<br />

then identified elements that failed to<br />

meet current regulations. TRIZ was<br />

used to identify optimal solutions in<br />

order to minimize the costs involved<br />

in making improvements to existing<br />

nuclear power plants.<br />

The database of wires and circuits<br />

essential to post-fire safe shutdown<br />

operations enables operators to<br />

identify affected systems and decide<br />

whether immediate isolation is<br />

required. The implementation of fire<br />

zones makes it easy to determine<br />

whether a zone lies along a safe<br />

shutdown path. The proposed method<br />

Operation and New Build<br />

The Application of Knowledge Management and TRIZ for solving the Safe Shutdown Capability in Case of Fire Alarms in Nuclear Power Plants ı Chia-Nan Wang, Hsin-Po Chen, Ming-Hsien Hsueh and Fong-Li Chin


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

is able to accurately identify zones<br />

requiring improvement for fire prevention<br />

or for other safety concerns. Previous<br />

regulatory evaluations determined<br />

only the degree of compliance;<br />

i.e., they gave no indication of whether<br />

a safe shutdown could actually be<br />

achieved. The proposed method helps<br />

to ensure that safe shutdown can be<br />

achieved, based on the safety requirements<br />

stipulated in existing regulations.<br />

Safe shutdown capability can<br />

be used as a criterion by which to<br />

identify the elements that cannot<br />

feasibly conform to regulations, such<br />

as areas where automatic fire detection<br />

and extinguishing systems cannot<br />

be installed. TRIZ is an innovative<br />

approach to problem-solving. It provides<br />

a range of possibilities by which<br />

to solve problems and the results are<br />

easily compiled to facilitate training<br />

procedures. Few existing studies on<br />

nuclear power plants apply directly to<br />

real-world cases. Knowledge management<br />

methods enable the construction<br />

of a knowledge base, thereby providing<br />

a means by which to integrate<br />

implicit and explicit knowledge. Its<br />

systematic integration of analysis and<br />

comparison data provide valuable a<br />

reference to practitioners in the field.<br />

Parameter settings based on<br />

current regulatory conditions and<br />

the use of knowledge management<br />

models enables quicker and more<br />

precise identification of the improvements<br />

required for compliance with<br />

existing regulations. A fire prevention<br />

database provides a valuable reference<br />

for the assessment of fire safety.<br />

Subsequent tasks include developing<br />

fire models and automatic analysis<br />

instruments based on fire dynamics,<br />

fire load, and fire risk probability,<br />

which all require such databases. The<br />

basic fire prevention database in this<br />

study meets the basic requirements<br />

for fire analysis and can be used for<br />

future studies of post-fire phenomena<br />

in nuclear power plants. The procedure<br />

outlined in this study provides a<br />

model for safety assessment of current<br />

nuclear power plants as well as a<br />

complete research framework for<br />

other fire-related research in nuclear<br />

power plants and even other types of<br />

safety measures. The nuclear power<br />

plant studied in this paper features<br />

three-loop pressurized water reactors.<br />

Therefore the details of the research<br />

procedure related to the water<br />

reactors are not necessarily applicable<br />

to other types of reactor. Data<br />

collection, analysis, and comparison<br />

would have to be performed anew<br />

to confirm its applicability.<br />

References<br />

| | Altshuller, G., Shulyak, L., Rodman, S.,<br />

1999. The Innovation Algorithm: TRIZ,<br />

Systematic Innovation and Technical<br />

Creativity. Technical Innovation Ctr.:<br />

Worcester, MA.<br />

| | Debowski, S., 2007. Knowledge<br />

Management. Wiley India Pvt. Ltd.<br />

| | Generic Letters GL 83-33, Position 2,<br />

1983. Water Curtain, October, 1983.<br />

| | Generic Letters GL 86-10, Position 3.6.2,<br />

1986. Fire Stop, April, 1986.(1.) NRC<br />

BTP APCSB 9.5-1 App. A , (1976)<br />

Fire Protection guide for Nuclear Power<br />

Plants, May, 1986.<br />

| | Hua, Z., Yang, J., Coulibaly, S., Zhang, B.,<br />

2006. Integration TRIZ with problemsolving<br />

tools: a literature review from<br />

1995 to 2006. International Journal of<br />

Business Innovation and Research 1:<br />

111-128.<br />

| | Information Notice 84-09, 1984.<br />

Lessons Learned from NRC Inspections<br />

of Fire Protection Safe Shutdown<br />

Systems (10 CFR 50, Appendix R).<br />

| | Mann, D., 2007. Hands-on Systematic<br />

Innovation. IFR Press: Clevedon, UK.<br />

| | National Fire Protection Association<br />

805, Performance-based Standard for<br />

Fire Protection for Light Water Reactor<br />

Electric Generating Plants, 2001 Edition.<br />

| | NEI 00-01, Rev.2, 2009. Guidance for<br />

Post Fire Safe Shut Down Circuit Analysis.<br />

| | NFPA805 National Fire Protection<br />

Association 805, Performance-based<br />

Standard for Fire Protection for Light<br />

Water Reactor Electric Generating<br />

Plants, 2001 Edition.<br />

| | NRC Branch Technical Position (BTP)<br />

9.5-1, 1981. Guidelines For Fire<br />

Protection For Nuclear Power Plants,<br />

CMEB, July 1981.<br />

| | NRC BTP APCSB 9.5-1 App. A , 1976.<br />

Fire Protection guide for Nuclear Power<br />

Plants.<br />

| | NRC Standard Review Plan 9.5-1, 1975.<br />

Fire Protection Program, November,<br />

1975.<br />

| | NRC, 1979. 10 CFR 50 Appendix R to<br />

Part 50 – Fire Protection Program For<br />

Nuclear Power Facilities Operating Prior<br />

To January 1.<br />

| | NRC, 1984. Information Notice 84-094<br />

Guidance IX.<br />

| | NRC, 2007. RG 1.189, Rev. 2 Section<br />

5.3, Fire Protection of Safe-Shutdown<br />

Capabilities.<br />

| | NRC, 2012. 10 CFR 50 Appendix A to<br />

Part 50, General Design Criterion 3.<br />

| | NUREG-1852, 2007. Demonstrating the<br />

Feasibility and Reliability of Operator<br />

Manual Actions in Response to Fire,<br />

Final Report, October, 2007.<br />

| | NUREG-1924, 2010. Electric Raceway<br />

Fire Barrier Systems in U.S. Nuclear.<br />

| | Rosner, D., Grote, B., Hartman, K,<br />

Hofling, B, Guericke, O., 1998. From<br />

natural language documents to<br />

sharable product knowledge: a<br />

knowledge engineering approach. In:<br />

Borghoff U.M., Pareschi, R. (Eds.),<br />

Information technology for knowledge<br />

management, pp. 35–51, Springer<br />

Verlag.<br />

| | Society of Fire Protection Engineers,<br />

2003. SFPE Hand Book.<br />

| | TPC Maanshan Nuclear Power Plant,<br />

1999. Final Safety Analyze Report.<br />

| | TRIZ: A New Approach to Innovative<br />

Engineering and Problem Solving, 1996<br />

AME Annual Conference in Milwaukee,<br />

WI, November 5-8.<br />

| | USNRC Generic Letter 77-<strong>02</strong>, 1977. Fire<br />

Protection Functional Responsibilities,<br />

Administrative Control and Quality<br />

Assurance.<br />

Authors<br />

Chia-Nan Wang<br />

Hsin-Po Chen<br />

Fong-Li Chin<br />

Ming-Hsien Hsueh<br />

Department of Industrial<br />

Engineering and Management<br />

National Kaohsiung University<br />

of Applied Sciences<br />

No.415, Jiangong Rd., Sanmin Dist.,<br />

Kaohsiung City 807<br />

Taiwan, China<br />

Department of Industrial<br />

Engineering and Management<br />

National Kaohsiung University<br />

of Applied Sciences<br />

No.415, Jiangong Rd., Sanmin Dist.,<br />

Kaohsiung City 807<br />

Taiwan, China<br />

OPERATION AND NEW BUILD 103<br />

Operation and New Build<br />

The Application of Knowledge Management and TRIZ for solving the Safe Shutdown Capability in Case of Fire Alarms in Nuclear Power Plants ı Chia-Nan Wang, Hsin-Po Chen, Ming-Hsien Hsueh and Fong-Li Chin


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

104<br />

DECOMMISSIONING AND WASTE MANAGEMENT<br />

Corrosion Processes of Alloyed Steels<br />

in Salt Solutions<br />

Bernhard Kienzler<br />

Introduction For many years, in Germany POLLUX canisters were considered as reference concept for spent<br />

nuclear fuel disposal casks. The cask consists of the shielding cask with a screwed-in lid and the inner cask with bolted<br />

primary and welded secondary lid. The spent fuel should be inserted in the final disposal cask in bins. The cylindrical<br />

wall and bottom of the inner cask consist of fine-grained steel 15 MnNi 6.3. The thickness of the cylindrical wall was<br />

designed according to the mechanical and shielding requirements and was 160 mm thick. The primary lid of the inner<br />

cask was also made of fine-grained steel. This lid was designed to keep the sealing function prior to and during the<br />

welding of the secondary lid. A plate made of neutron-moderating and absorbing materials (carbon/boron mixture)<br />

was attached to the primary lid. The secondary lid is designed as a welded lid. The base body of the shielding cask<br />

consisted of ductile cast iron (GGG 40). The wall thickness was designed according to the requirements for the shielding<br />

and was 265 mm thick. The weight of the POLLUX cask was 65 Mg [1]. The whole POLLUX cask consisted of actively<br />

corroding steels.<br />

The corrosion behavior of the POLLUX<br />

materials in salt solution for temperatures<br />

up to 200°C were investigated<br />

[2]. Both materials showed high corrosion<br />

rates especially at elevated<br />

temperatures and frequently the question<br />

was asked why not using alloyed<br />

steels. In fact, alloyed steels are developed<br />

to be corrosion resistant, and the<br />

steels are widely used especially for<br />

corrosion-resistant applications.<br />

Alloyed steels such as stainless<br />

steels do not readily corrode, rust or<br />

stain in contact with water as finegrained<br />

or cast iron steels. However,<br />

the alloyed steels are not fully stainproof<br />

in low-oxygen or high-salinity<br />

environments. There are various<br />

grades and surface finishes of stainless<br />

steel to suit the environment the<br />

alloy must endure. Stainless steel is<br />

used where both the properties of<br />

steel and corrosion resistance are<br />

required.<br />

Stainless steels differ from carbon<br />

steel by the amount of chromium<br />

present. Unprotected carbon steel<br />

rusts when exposed to air and<br />

moisture. The iron oxide film has<br />

lower density than steel, the film<br />

expands and tends to flake and fall<br />

away. In comparison, stainless steels<br />

contain sufficient chromium to<br />

undergo passivation, forming an inert<br />

film of chromium oxide on the surface.<br />

This layer prevents further corrosion<br />

by blocking oxygen diffusion to the<br />

steel surface and stops corrosion from<br />

spreading into the bulk of the metal.<br />

Passivation occurs only if the proportion<br />

of chromium is high enough<br />

and oxygen is present.<br />

In the scope of corrosion studies<br />

of high-level waste canister materials,<br />

the corrosion behavior of several<br />

alloyed materials was investigated.<br />

The materials comprised nickel based<br />

alloys (Hastelloy C22 and C4), and<br />

chromium-nickel steels. Furthermore,<br />

titanium alloys and copper-nickel<br />

alloys were taken into the investigations.<br />

These alloys are not covered in<br />

this contribution.<br />

The recommendations of the<br />

German High-Level Waste Commission<br />

[3] are reflected in the German law for<br />

amendment of the site selection law<br />

(passed by the German Parliament,<br />

March 23, 2017 [4]). Especially the<br />

maximum temperature condition has<br />

been changed. The maximum temperature<br />

at the canister surfaces is now<br />

limited to 100 °C, and the retrievability<br />

of the wastes during the operational<br />

phase of the disposal and the recoverability<br />

of the wastes for a period of 500<br />

years is need to be taken into account.<br />

Corrosion mechanisms<br />

of alloyed steels<br />

The corrosion resistance of stainless<br />

steel (Cr-Ni steel) known under<br />

atmospheric conditions depends on<br />

the chromium content of the alloy.<br />

Chromium leads to the formation of a<br />

passive layer, the so-called chromium<br />

oxide skin, which spontaneously<br />

forms in air and protects the material<br />

underneath from corrosion. By<br />

alloying different chromium and<br />

molybdenum fractions, the corrosion<br />

resistance can be adjusted to the<br />

environmental conditions. The low<br />

corrosion rates of Cr-Ni steels are due<br />

to the build-up of passive layers (oxide<br />

layers) on the surface, which are<br />

re-established under the conditions of<br />

low-concentrated solutions.<br />

The stability of container materials<br />

in a deep underground disposal is<br />

influenced by various uniform and<br />

local corrosion processes. These<br />

processes are controlled by the local<br />

geochemical conditions, in particular<br />

pH, redox potential and chloride<br />

concentration. Iron and steels are not<br />

thermodynamically stable in contact<br />

with water or saline solution. A<br />

number of different corrosion processes<br />

are described depending on a<br />

variety of factors [5]. For metals, two<br />

types of corrosion occur: general and<br />

localized corrosion.<br />

• General or uniform corrosion<br />

results in a relatively uniform mass<br />

loss over the entire area of the<br />

sample. General corrosion effects<br />

are predictable. Cast irons and<br />

steels corrode uniformly when<br />

exposed to open atmospheres, soils<br />

and natural waters as well as in salt<br />

solutions.<br />

• Localized corrosion occurs at discrete<br />

sites on the metal surface.<br />

The areas immediately adjacent to<br />

the localized corrosion normally<br />

corrode to a much lesser extent.<br />

These types of corrosion are less<br />

common in atmospheric exposure<br />

than in immersion exposures.<br />

Corrosion activity at localized<br />

corrosion sites may vary with<br />

changes of the water composition,<br />

defects in passivation layers,<br />

changes in contaminants or<br />

pollutants, changes in the electrolyte<br />

and by formation of<br />

galvanic cells. The predominant<br />

forms of localized corrosion are<br />

pitting and crevice corrosion.<br />

• Pitting corrosion is especially<br />

prevalent in metals that form a<br />

protective oxide layer. Pitting<br />

can be initiated on an open,<br />

freely-exposed surface or at<br />

imperfections in the passivation<br />

layer. Deep, even fully penetrating<br />

pits can develop with<br />

Decommissioning and Waste Management<br />

Corrosion Processes of Alloyed Steels in Salt Solutions ı Bernhard Kienzler


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

only a relatively small amount<br />

of metal loss. Pitting can occur<br />

isolated or as group of pits<br />

which may coalesce to form a<br />

large area of damage.<br />

• Crevice corrosion occurs in<br />

crevices where the environment<br />

differs from the surrounding<br />

bulk environment. The different<br />

environments result in<br />

corrosion because of differences<br />

in concentration (e.g.,<br />

oxygen, pH, and ferric ions). If<br />

there is an oxygen concentration<br />

difference, corrosion will<br />

proceed at crevices where less<br />

oxygen is available than in the<br />

environment surrounding the<br />

crevice. Crevices are formed<br />

when two surfaces are in<br />

proximity to one another, such<br />

as when two metal surfaces are<br />

in close contact.<br />

• Contact (galvanic) corrosion<br />

occur when different metals are<br />

in contact in a common electrolyte.<br />

At current flows between<br />

the two metals, the less noble<br />

metal (the anode) corrodes at a<br />

faster rate than would have<br />

occurred if the metals were not<br />

in contact. In this case, the rate<br />

of corrosion depends on the<br />

relative areas of the metals in<br />

contact and the composition<br />

(conductivity) of the electrolyte.<br />

• Stress corrosion cracking<br />

(SCC) requires the simultaneous<br />

presence of tensile<br />

stresses (effect of external loads<br />

or welding / bending) and<br />

specific environmental factors.<br />

• Intergranular attack is caused<br />

by carbon diffusion to the grain<br />

boundaries and precipitation as<br />

chromium carbide. This effect<br />

removes chromium from the<br />

metal phase (solid solution)<br />

leaving a lower chromium<br />

content adjacent to the grain<br />

boundaries.<br />

Especially in environments with high<br />

chloride concentrations, chloride<br />

promotes the breakdown of the oxide<br />

layer. In the presence of chloride ions,<br />

oxygen can be displaced by chloride<br />

ions in the oxide layer of the passivated<br />

metal. The addition of further<br />

chloride ions results in a region which<br />

is no longer protected by the oxide<br />

layer. This site now offers an attack<br />

point for further corrosion. Under<br />

favorable circumstances, a so-called<br />

re-passivation may occur: the chloride<br />

ion is displaced again by oxygen, and<br />

the protective oxide layer is “repaired”<br />

again. Otherwise, the pitting corrosion<br />

continues. The rate of displacement<br />

of oxygen by chloride in the<br />

passivation layer is the measure of the<br />

incubation period for the occurrence<br />

of local corrosion processes. The<br />

following mechanisms effect pitting<br />

corrosion [6]:<br />

• The dissolved oxygen concentration<br />

outside of the pit is considerably<br />

higher than in the hole. The<br />

low oxygen concentration in the<br />

pit hinders re-passivation of the<br />

metal.<br />

• The small pit forms an anode, the<br />

remaining surface represents the<br />

cathode. The corrosion rate is<br />

determined by the ratio of the<br />

cathode to anode area.<br />

• The metal dissolves according<br />

Me n+ + H 2 O + k MeOH (n-1)+ +<br />

H + , reducing the pH.<br />

• Critical potential must exceed a<br />

certain critical potential value. In<br />

salt solution, the critical potential<br />

is defined by E pit = A + B log [Cl − ]<br />

with Cl − is the bulk chloride<br />

concentration. B is generally in<br />

the range 60-90 mV [7]. Critical<br />

pitting potentials (E pit ) of 1.4301<br />

Cr-Ni steel (type 304, UNS S30400)<br />

are reported by Yashiro et al [8] as<br />

a function of temperature (373 K<br />

to 523 K) and chloride (Cl − )<br />

concentration (0.01 to 2 mol/kg-<br />

H 2 O). Steady polarization tests<br />

were performed at discrete intervals<br />

around Epit. Results were<br />

expressed by E pit = A − B log [Cl − ].<br />

In regard to temperature dependency,<br />

the constant A decreased<br />

with temperature, while B was<br />

almost constant up to 448 K.<br />

• In the presence of Cl − , the dissolved<br />

metal in the pit reacts with<br />

chloride forming iron chlorides<br />

which hydrolyses (FeCl 2 +H 2 O vk<br />

FeClOH + Cl − + H + ) and reduce<br />

the pH.<br />

The actual water consumption for<br />

pitting corrosion is substantially lower<br />

than in the case of uniform surface<br />

corrosion of unalloyed steels. Carbon<br />

steels also shows a passivation in the<br />

alkaline environment, e.g. at pH > 12<br />

in concrete constructions [9].<br />

In contrast to alloyed steels,<br />

unalloyed carbon steels do not build<br />

up a protective layer under low or<br />

slightly basic pH conditions, since<br />

the alloying element chromium is<br />

missing. Under acidic to basic pH<br />

conditions voluminous iron oxides /<br />

iron hydroxides are formed, which<br />

generally do not adhere to the underlying<br />

material. Therefore, the steel is<br />

not protected but the oxidation is<br />

maintained under the influence of<br />

moisture and oxygen. This reaction<br />

observed in the unalloyed steels is<br />

referred to as an active corrosion<br />

process in which iron reacts to iron<br />

oxide/hydroxide. Numerous experiments<br />

have shown that the active<br />

corrosion of the unalloyed steels is<br />

uniform and at a largely constant rate<br />

[10–16]. This behavior allows predicting<br />

the mass loss or thickness<br />

reduction of the disposal cask to a<br />

certain degree.<br />

The corrosion experiments reported<br />

here were performed in salt<br />

solutions. Under reducing conditions<br />

as they prevail in a deep geological<br />

disposal, the corrosion process of<br />

carbon steel consumes water and<br />

generates hydrogen. During the corrosion<br />

process, dissolved iron reacts<br />

with the aqueous medium forming<br />

ferrous hydroxides with divalent iron<br />

(Fe II ). At 7 < pH < 9, the observed<br />

solid corrosion products are magnetite<br />

(Fe 3 O 4 ) and amorphous iron<br />

hydroxides. At sufficiently low redox<br />

potentials (absence of oxygen) in<br />

chloride solutions, Cl − ions react with<br />

amorphous iron hydroxides forming<br />

the reaction product “green rusts”.<br />

This compound has the formula<br />

[Fe II 3Fe III (OH) 8 ]Cl×H 2 O and can be<br />

formed at [Cl − ]/[OH − ] > 1 [17]. It<br />

consists of both Fe II and trivalent iron<br />

(Fe III ). In contact with oxygen, green<br />

rust transforms quickly to magnetite.<br />

In the presence of Mg-rich brines,<br />

(Fe,Mg)(OH) 2 and Fe(OH) 2 Cl compounds<br />

were found and characterized<br />

[18].<br />

Materials and methods<br />

When the corrosion experiments were<br />

started, the boundary conditions for<br />

the research on container materials<br />

for highly radioactive waste resulted<br />

from the requirements defined by<br />

pouring the molten highly radioactive<br />

glass directly into the canister, apply<br />

the necessary welding and decontamination<br />

of the containers and by<br />

the requirement for transport, interim<br />

storage and final disposal. For the<br />

POLLUX canister, the influence of the<br />

production and sealing of a final<br />

storage canister was considered, and<br />

U-shaped samples, welded samples<br />

using different welding procedures, as<br />

well as contact samples were prepared<br />

for the experiments. In particular, to<br />

assess the influence of the welding on<br />

the corrosion processes, different<br />

treatments of the samples were<br />

applied, including the delivery state,<br />

heat-treated samples, welded and<br />

subsequently heat-treated samples.<br />

DECOMMISSIONING AND WASTE MANAGEMENT 105<br />

Decommissioning and Waste Management<br />

Corrosion Processes of Alloyed Steels in Salt Solutions ı Bernhard Kienzler


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

DECOMMISSIONING AND WASTE MANAGEMENT 106<br />

Material<br />

Material<br />

description<br />

A comprehensive description of the<br />

sample shape and treatment has been<br />

published [19]. Further experiments<br />

included contact samples where<br />

different steels were screwed together<br />

in close contact and corrosion tests<br />

under γ irradiation. The whole suite of<br />

steels under investigations ale listed in<br />

Table 1.<br />

Two different sample types were<br />

produced to test the materials for<br />

mass loss, pitting corrosion, crack<br />

corrosion and stress corrosion<br />

Material<br />

number<br />

Density<br />

g/cm 3<br />

Ni based alloys Hastelloy C4 Ni Mo 16 Cr 16 Ti 2.4610 8.669<br />

Ti alloys Titan – Palladium Ti 99.7 – Pd<br />

Ti 99.7 - Pd EG<br />

Fe based alloys Fine-grained steel FStE 255<br />

TStE 460<br />

15 Mn Ni 6.3<br />

DC 01 / St 12<br />

ST 37-2<br />

Cr-Ni steel<br />

Cu alloys<br />

Nodular cast steel<br />

Ni-Resist D2<br />

Ni-Resist D4<br />

Nirosta<br />

GGG 40.3<br />

GGG-Ni Cr 20.2<br />

GGG-Ni Si Cr 30.55<br />

X2CrNi19-11<br />

Cu.99<br />

Cu-Ni 70/30<br />

Cu-Ni 90/10<br />

Ni alloys Nickel 99.9<br />

Ni/Cu 70/30<br />

| | Tab. 1.<br />

Metal alloys for construction of waste canisters under investigation at KIT-INE.<br />

3.7<strong>02</strong>5<br />

3.7035<br />

1.0566<br />

1.8915<br />

1.6210<br />

1.0330<br />

1.0038<br />

0.7043<br />

0.7660<br />

0.7680<br />

1.4833<br />

1.4306<br />

4.0000<br />

4.7000<br />

4.9000<br />

2.4068<br />

2.4360<br />

4.593<br />

4.593<br />

7.814<br />

7.671<br />

7.512<br />

7.85<br />

7.856<br />

6.955<br />

7.36<br />

7.596<br />

8.<strong>02</strong>2<br />

7.956<br />

9.198<br />

8.866<br />

8.998<br />

8.48<br />

8.51<br />

cracking (SCC). For the determination<br />

of the mass loss, sheet metal specimens<br />

with the dimensions 40 mm ×<br />

20 mm were cut in the respectively<br />

available sheet thicknesses. The mass<br />

loss was determined only in the case<br />

of samples in the delivery condition.<br />

The susceptibility to pitting corrosion<br />

as well as the susceptibility to crack<br />

corrosion could be assessed also.<br />

The Ni-Resist steels have been<br />

included in the investigation program<br />

because these steels are specified for<br />

handling salt solutions such as sea<br />

water. Lower uniform corrosion rates<br />

were expected as in the case of fine<br />

grained steel. After the exposure time,<br />

the samples were recovered from the<br />

corrosion medium and the specimens<br />

were cleaned from the adhering salts<br />

and corrosion products by pickling in<br />

suitable solutions according to ASTM<br />

guidelines [20]. Then the specimens<br />

were cleaned in alcohol and examined<br />

for general and local corrosions as<br />

well as for stress corrosion cracking.<br />

The general corrosion (integral corrosion<br />

rate) was calculated from the<br />

integral weight losses determined by<br />

gravimetry and from the respective<br />

material densities. The specimens<br />

were examined for local corrosion and<br />

stress corrosion cracking by microscopic<br />

evaluation and with the help of<br />

metallographic cross-sections, measurements<br />

of pit depths and surface<br />

profiles.<br />

Results and discussion<br />

General corrosion<br />

Due to the fact that localized corrosion<br />

processes are observed in the<br />

experiments, the mass loss rate is used<br />

for comparisons. The general corrosion<br />

rate relies on uniform corrosion<br />

of the surfaces and is not considered<br />

reasonably for alloyed steel. Figure 1<br />

and Figure 2 show the mass loss and<br />

the corresponding mass loss rates for<br />

a) mass loss<br />

b) mass loss rate<br />

| | Fig. 1.<br />

Measured mass loss and mass loss rates of Hastelloy in MgCl 2 -rich (red) and NaCl solution (blue) as function of time at various temperatures.<br />

a) mass loss<br />

b) mass loss rate<br />

| | Fig. 2.<br />

Measured mass loss and mass loss rates of Cr-Ni steels (1.4306 and 1.4388) in MgCl 2 -rich (red) and NaCl solution (blue) as function of time at 150 °C.<br />

Decommissioning and Waste Management<br />

Corrosion Processes of Alloyed Steels in Salt Solutions ı Bernhard Kienzler


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<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

DECOMMISSIONING AND WASTE MANAGEMENT 108<br />

a) mass loss<br />

b) mass loss rate<br />

| | Fig. 3.<br />

Measured mass loss and mass loss rates of fine-grained steel (1.6210) in MgCl 2 -rich (red) and NaCl solution (blue) as function of time at 150 °C.<br />

Hastelloy and for the two Cr-Ni steels.<br />

The Hastelloy experiments covered a<br />

temperature range between 90 °C and<br />

170 °C, whereas the CR-NI steels were<br />

investigated at 150 °C, only.<br />

For Hastelloy, all mass loss rates<br />

were found below 12 g m -2 yr. -1 showing<br />

no distinct time dependence. For<br />

the experiments with Cr-Ni steels, the<br />

initial mass loss rates decreased and<br />

remained for the long term below<br />

15 g m -2 yr. -1 . The effect of the solution<br />

type on the mass loss rates for Cr-Ni<br />

steels was not significant. Also, the<br />

differences of the mass loss and mass<br />

loss rates between 1.4306 and 1.4833<br />

steels were marginal. Concerning the<br />

temperature effect of the general<br />

corrosion of Hastelloy, relatively high<br />

mass losses were found at 90°C after<br />

676 days. At higher temperatures, the<br />

exposure period remained below 500<br />

days. The reason for the increased<br />

mass losses could be explained by<br />

crevice corrosion of the Hastelloy C22<br />

in MgCl 2 rich solution showing pit<br />

depths of about 200 µm. The scatter<br />

of mass losses is correlated to local<br />

corrosion processes.<br />

For comparison, the mass loss and<br />

mass loss rates of the fine-grained<br />

steel 1.6210 is shown in Figure 3. In<br />

this case, the mass loss rates were by a<br />

factor of 50 higher in comparison to<br />

the Cr-Ni steel in NaCl solutions and<br />

by a factor about 100 higher in MgCl 2<br />

solution after about 500 days (150 °C).<br />

The uniform mass loss rates of<br />

the Ni-Resist steels were found in<br />

the range of the Cr-Ni steels at<br />

20 ± 7 g m 2 yr. 1 for steel 0.7660<br />

and 12 ± 9 g m -2 yr. -1 for 0.7680,<br />

respectively. These values are also<br />

significantly lower in comparison to<br />

the fine-grained steel 1.6210.<br />

| | Fig. 4.<br />

Crevice corrosion in Hastelloy C22 after 676<br />

days in MgCl 2 rich solution at 90 °C showing<br />

depths of about 200 µm.<br />

Local corrosion phenomena<br />

The breakdown of passivity (the<br />

breaching of the protective barrier<br />

provided by the passive film) initiates<br />

the most damaging kinds of corrosion,<br />

the localized forms of corrosion,<br />

pitting, crevice corrosion, intergranular<br />

attack, and stress corrosion. The<br />

induction period for pitting corrosion<br />

starts with the initiation of the breakdown<br />

process by the introduction of<br />

breakdown conditions and ends when<br />

the localized corrosion density begins<br />

to rise. Unfortunately, electrochemical<br />

corrosion studies were applied<br />

only for carbon steel and the influence<br />

of chemical species in brines have<br />

been investigated [21]. For this<br />

reason, corrosion potential for pitting<br />

corrosion have not been determined<br />

for the investigated alloyed steels.<br />

In brine media, localized corrosion<br />

has been investigated over the complete<br />

range of chloride concentrations.<br />

The Cl- concentration, however,<br />

is not as critical as pH and temperature,<br />

since the attack can occur at any<br />

concentration over the minimum<br />

value. Factors such as incubation<br />

time, severity, and frequency of<br />

occurrence can be influenced by the<br />

concentration.<br />

Localized corrosion was observed<br />

for all alloyed steels. In the case of<br />

Hastelloy C22, the first pits occurred<br />

after 275 days in the MgCl 2 rich<br />

solution at 90 °C. These pits had<br />

depths of about 10 µm. After 552<br />

days, the depths increased to 20 µm<br />

and after 676 days, a pit’s depth of<br />

200 µm was found in a crevice. In the<br />

MgCl 2 solution 2, even deeper pits<br />

were detected. In NaCl solution, after<br />

552 days, the pit’s depth amounted to<br />

16 µm.<br />

The average pit depths as function<br />

of time in the steels 1.4306 and 1.4833<br />

are shown in Figure 5.<br />

In contrast to the observations<br />

for Hastelloy, the depths of the pits<br />

were significantly deeper after about<br />

3 months. The pits showed relative<br />

a) Steel 1.4306 at 150°C<br />

| | Fig. 5.<br />

Average pit depths determined in untreated Cr-Ni steels as function of time.<br />

b) Steel 1.4833 at 150°C<br />

Decommissioning and Waste Management<br />

Corrosion Processes of Alloyed Steels in Salt Solutions ı Bernhard Kienzler


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

a) Stress corrosion cracking in the heat<br />

affected zone of a welding seam:<br />

TSS Experiment at Asse salt mine<br />

temperature: 180 °C<br />

Duration: about 11 years.<br />

| | Fig. 6.<br />

Localized corrosion phenomena of steel 1.4306: Stress corrosion cracking along grain boundaries.<br />

high depth variations. The immersion<br />

tests were terminated after about 500<br />

days, therefore an increase in the pit’s<br />

depths as determined in the case of<br />

Hastelloy was not observed. The<br />

average pit depth of both steel was<br />

found in the range of 30 to 40 µm.<br />

The steels 1.4306 and 1.4833<br />

showed significant stress corrosion<br />

cracking at 150 °C (tests at 90 °C were<br />

not performed). Figure 6 shows polished<br />

micrographs of steel 1.4306<br />

specimen in contact with dry rock salt<br />

(a) and immersed in NaCl solution.<br />

Localized corrosion was found in<br />

both cases, even in the almost dry<br />

con ditions established in the TSS<br />

experiment performed in the Asse salt<br />

mine [22]. The penetration depths<br />

of the cracks were measured in<br />

the mm range. Contact samples in<br />

MgCl 2 solution showed even more<br />

pronounced stress corrosion cracking<br />

[2].<br />

With Hastelloy C4 corrosion tests<br />

under γ-irradiation of 10 Gy/h were<br />

performed (fuel element storage<br />

pool at Dido test reactor at the<br />

Research Center Juelich). Different<br />

types of samples were examined:<br />

plane samples as delivered, plane<br />

samples with removed oxide layer<br />

on the surface, U-shaped welded<br />

samples, crevice samples, and samples<br />

| | Fig. 7.<br />

Intergranular corrosion in a Ni-Resist D4<br />

sample after 776 days in MgCl 2 solution<br />

at 90 °C.<br />

b) Stress corrosion cracking of a plane<br />

specimen of steel 1.4306 after 422 days<br />

in NaCl solution at 150°C.<br />

with different welding procedures<br />

such as tungsten inert gas welding<br />

(TIG) or electron beam welding (EB).<br />

Significant deviation of the observed<br />

mass losses in comparison to test without<br />

irradiation were not found.<br />

Almost all Ni-Resist steel samples<br />

showed intergranular corrosion effects<br />

(Figure 7). These referred to samples<br />

as delivered and to crevice samples.<br />

Summary and conclusions<br />

The results of the corrosion experiments<br />

with Cr-Ni steels, Hastelloy and<br />

the Ni-Resist materials revealed a<br />

significantly lower general corrosion<br />

rate (mass loss rate) in comparison to<br />

the fine-grained steels. On the other<br />

hand, these materials were subdued<br />

to localized corrosion processes such<br />

as pitting corrosion, crevice corrosion,<br />

intergranular corrosion and stress<br />

corrosion cracking. The local corrosion<br />

processes were enhanced in<br />

welded or in contact specimen. In<br />

many cases, the localized corrosion<br />

phenomena were found only after<br />

certain incubation periods. Especially<br />

in the case of Hastelloy, the incubation<br />

period was about 9 months at 90 °C in<br />

MgCl 2 solution and the pitting corrosion<br />

rate was relatively high. Stress<br />

corrosion cracking by intergranular<br />

corrosion of the Cr-Ni steels penetrated<br />

deep into the materials. Intergranular<br />

corrosion was also found in<br />

the Ni-Resist steels.<br />

As a consequence of the occurrence<br />

of localized corrosion processes<br />

as well as the unpredictable incubation<br />

times of these processes, one<br />

might understand the decision to<br />

apply uniformly corroding steels for<br />

waste canisters, even if the general<br />

corrosion rate would be by a factor up<br />

to 1,000 higher.<br />

The mass loss is proportional to the<br />

hydrogen produced under reducing<br />

conditions in a deep disposal. A<br />

POLLUX cask has a surface area of<br />

about 30 m 2 . Under extreme conditions,<br />

15 kg of steel could be corroded<br />

per year in NaCl solution, forming<br />

360 mol H 2 per year (8 m 3 standard<br />

conditions). Hydrogen keeps a reducing<br />

environment, however, by<br />

increasing pressure it acts as driving<br />

force for gas, solution and contaminant<br />

transport. Internationally efforts<br />

are undertaken to reduce the potential<br />

amount of hydrogen produced by<br />

corrosion phenomena.<br />

Based on the measurements<br />

reported in this contribution, Cr-Ni<br />

steels seem not to provide a reasonable<br />

solution for a long-lived stable<br />

waste package. Even, if the hydrogen<br />

production is reduced, the long-term<br />

sealing function of these steels is<br />

unclear. Under the almost dry condition<br />

of the in-situ experiment (TSS)<br />

in the Asse mine, stress corrosion<br />

cracking in the heat affected zone of<br />

a welding seam of Cr-Ni steel was<br />

observed after 11 years at 180 °C.<br />

Acknowledgment<br />

The corrosion studies of canister<br />

materials for heat producing wastes<br />

cover exclusively the research performed<br />

by Dr. Emmanuel Smailos and<br />

his working group. Until his retirement<br />

in 2004, Dr. Smailos was responsible<br />

for the corrosion studies of<br />

various materials at the Institute for<br />

Nuclear Waste Disposal (INE).<br />

References<br />

[1] H. Lahr, H.-O. Willax, and H. Spilker,<br />

Conditioning of spent fuel for interim<br />

and final storagein the pilote conditioning<br />

plant (PKA) at Gorleben, in<br />

International Symposium on Storage of<br />

Spent Fuel from Power Reactors,<br />

Vienna, Austria, 9-13 November 1998,<br />

1998.<br />

[2] E. Smailos and B. Fiehn, Korrosionsuntersuchungen<br />

an der Werkstoffkombination<br />

des POLLUX-Behaelters<br />

zur direkten Endlagerung abgebrannter<br />

Brennelemente in Steinsalz formationen,<br />

Forschungszentrum Karlsruhe, KfK-<br />

4552, 1989.<br />

[3] Kommission Lagerung hoch radioaktiver<br />

Abfallstoffe, ABSCHLUSSBERICHT:<br />

Verantwortung für die Zukunft: Ein faires<br />

und transparentes Verfahren für die<br />

Auswahl eines nationalen Endlagerstandortes,<br />

Geschäftsstelle der<br />

Kommission Lagerung hoch radioaktiver<br />

Abfallstoffe, K-Drs 268, 2016.<br />

[4] Gesetz zur Fortentwicklung des<br />

Gesetzes zur Suche und Auswahl eines<br />

Standortes für ein Endlager für Wärme<br />

entwickelnde radioaktive Abfälle und<br />

anderer Gesetze, 2017.<br />

[5] Uhligs corrosion handbook, 3 rd ed<br />

( Online-Ausg.) ed. Hoboken, N.J: Wiley,<br />

2011.<br />

DECOMMISSIONING AND WASTE MANAGEMENT 109<br />

Decommissioning and Waste Management<br />

Corrosion Processes of Alloyed Steels in Salt Solutions ı Bernhard Kienzler


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

DECOMMISSIONING AND WASTE MANAGEMENT 110<br />

[6] R. Newman, Pitting Corrosion of Metals,<br />

Electrochem. Soc. Interface Vol. 19,<br />

pp. 33-38, 2010<br />

[7] J. R. Galvele, Transport processes and<br />

the mechanism of pitting of metals,<br />

J. Electrochem. Soc. , Vol. 123,<br />

pp. 464-474 1976.<br />

[8] H. Yashiro, K. Tanno, S. Koshiyama, and<br />

K. Akashi, Critical Pitting Potentials for<br />

Type 304 Stainless Steel in High-<br />

Temperature Chloride Solutions<br />

Corrosion, Vol. 52, pp. 109-114, 1996.<br />

[9] George R. Brubaker and P. B. P. Phipps,<br />

Corrosion chemistry, Washington, D.C.:<br />

American Chemical Society, 1979.<br />

[10] E. Smailos, W. .Schwarzkopf, R. Köster,<br />

and K. H. Gruenthaler, Advanced<br />

corrosion studies on selected packaging<br />

materials for disposal of HLW canisters<br />

in rock salt, in Corrosion Problems<br />

Related to Nuclear Waste Disposal:<br />

A Working Party Report, European<br />

Federation of Corrosion, Ed., ed: The<br />

Institute of Materials, 1992, pp. 23-31.<br />

[11] E. Smailos, W. Schwarzkopf , B. Kienzler,<br />

and K. R., Corrosion of Carbon-Steel<br />

Containers for Heat-Generating Nuclear<br />

Waste in Brine Environments Relevant<br />

for a Rock-Salt Repository, in Scientific<br />

Basis for Nuclear Waste Management:<br />

Proc.of the 15th Internat.Symp.,<br />

Strasbourg, November 4-7, 1991, 1992,<br />

pp. 399-406.<br />

[12] E. Smailos, Corrosion of high-level<br />

waste packaging materials in disposal<br />

relevant brines, Nuclear Technology,<br />

Vol. 104, pp. 343-350, 1993.<br />

[13] E. Smailos, I. Azkarate, J. A. Gago,<br />

P. van Iseghem, B. Kursten, and<br />

T. McMenamin, Corrosion on metallic<br />

HLW container materials, in Fourth<br />

European Conference on Management<br />

and Disposal of Radioactive Waste,<br />

1997, pp. 209-223.<br />

[14] E. Smailos, A. Martínez-Esparza,<br />

B. Kursten, G. Marx, and I. Azkarate.,<br />

Corrosion evaluation of metallic<br />

materials for long-lived HLW/spent<br />

fuel disposal containers, Forschungszentrum<br />

Karlsruhe, FZKA 6285, 1999.<br />

[15] E. Smailos, M. A. Cunado, I. Azkarate,<br />

B. Kursten, and G. Marx, Long-term<br />

performance of candidate materials for<br />

HLW/spent fuel disposal containers,<br />

Forschungszentrum Karlsruhe, Wissenschaftliche<br />

Berichte, FZKA-6809, 2003.<br />

[16] E. Smailos, Influence of gamma<br />

radiation on the corrosion of carbon<br />

steel, heat-generating nuclear waste<br />

packaging in salt brines, IAEA, Wien<br />

IAEA TECDOC-1316 Effects of Radiaton<br />

and Environmental Factors on the<br />

Durability of Materials in Spent Fuel<br />

Storage and Disposal, 1995.<br />

[17] A. Raharinaivo, G. Arliguie,<br />

T. Chaussadent, G. Grimaldi, V. Pollet,<br />

and G. Taché, La corrosion et la<br />

protection des aciers dans le béton,<br />

Paris: Presses de l'École Nationale des<br />

Ponts et Chaussées, 1998.<br />

[18] B. Grambow, E. Smailos, H. Geckeis,<br />

R. Müller, and H. Hentschel, Sorption<br />

and reduction of uranium(VI) on iron<br />

corrosion products under reducing saline<br />

conditions, Radiochimica Acta, Vol.<br />

74, pp. 149-154, 1996.<br />

[19] E. Smailos, R. Köster, and<br />

W. Schwarzkopf, Korrosionsuntersuchungen<br />

an Verpackungsmaterialien<br />

für Hochaktive Abfälle, European Appl.<br />

Res. Rept. - Nucl. Sci. Technol., Vol. 5,<br />

pp. 175-222, 1983.<br />

[20] ASTM G 1- 72, Recommended Practice<br />

for Preparing, Cleaning and Evaluation<br />

of Corrosion Test Specimens, Annual<br />

Book of ASTM Standards, Vol. Part 10,<br />

p. 489, 1974.<br />

[21] A. M. Farvaque-Bera and E. Smailos,<br />

Electrochemical Corrosion Studies on a<br />

Seleted Carbon Steel for Application in<br />

Nuclear Waste Disposal Containers:<br />

Influence of Chemical Species in Brines<br />

on Corrosion, Kernforschungszentrum<br />

Karlsruhe, KfK-5354, 1994.<br />

[22] W. Bechthold, E. Smailos,<br />

S. Heusermann, W. Bollingfehr,<br />

B. B. Sabet, T. Rothfuchs, P. Kamlot,<br />

J. G. Olivella, and F. D. Hansen,<br />

Back filling and sealing of underground<br />

repositories for radioactive waste in<br />

salt (Bambus II project). Final report,<br />

European Commission, EUR-20621-EN,<br />

2004.<br />

Author<br />

Dr. Bernhard Kienzler<br />

Karlsruhe Institute of<br />

Technology (KIT)<br />

Institut für Nukleare<br />

Entsorgung (INE)<br />

Hermann-von-Helmholtz Platz 1<br />

76344 Eggenstein-Leopoldshafen<br />

Germany<br />

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Decommissioning and Waste Management<br />

Corrosion Processes of Alloyed Steels in Salt Solutions ı Bernhard Kienzler


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

Design and Development of a Radioeco<br />

logical Domestic User Friendly Code<br />

for Calculation of Radiation Doses and<br />

Concentration due to Airborn Radionuclides<br />

Release During the Accidental<br />

and Normal Operation in Nuclear<br />

Installations<br />

A. Haghighi Shad, D. Masti, M. Athari Allaf, K. Sepanloo, S.A.H. Feghhi and R. Khodadadi<br />

1.1 Introduction Though nuclear power is a good source of energy and is not generally a threat, a major reactor<br />

accident can lead to a catastrophe for people and the environment. The major health and environmental threat would<br />

be due to the escape of the fission products into the atmosphere. There have been instances of nuclear reactor accidents<br />

like the heavy water cooled and moderated reactor at Chalk River in Canada in 1952, the graphite moderated gas cooled<br />

reactor at Sellafield in Britain in 1957, the boiling water reactor at Idaho Falls in US in 1961, the pressurized water<br />

reactor on Three Mile Island in the US in 1979, the graphite moderated water cooled reactor at Chernobyl in Ukraine in<br />

1986, the sodium cooled fast breeder reactor at Monju in Japan in 1995 [Makhijani, 1996] and the boiling water reactor<br />

at Fukushima Daiichi NPP in Japan following an earthquake and tsunami in 2011. Among them, Chernobyl and<br />

Fukushima completely changed the human perception of radiation risk. On April 26, 1986, USSR suffered a major<br />

accident, which was followed by an extensive release to the atmosphere of large quantities of radioactive materials. An<br />

explosion and fire released huge quantities of radioactive particles into the atmosphere, which spread over much of the<br />

western USSR and Europe. The Chernobyl disaster was one of the two maximum classified event (level 7) on the<br />

International Nuclear Event Scale (the other being the Fukushima Daiichi nuclear disaster happened in 2011) and was<br />

the worst nuclear power plant accident in history in terms of cost and the resulting deaths. The battle to contain the<br />

contamination and avert a greater catastrophe ultimately involved over 500,000 workers and cost an estimated<br />

18 billion rubles. During the accident itself, 31 people died, and long-term effects such as cancers and deformities are<br />

still being accounted for. Unfortunately, the other severe accident happened on March 11, 2011; a powerful earthquake<br />

(magnitude 9.0) hit off the east coast of Japan. The tsunami triggered by the earthquake surged over the east coast of<br />

the Tohoku region, including Fukushima. The Fukushima Daiichi NPP’s cooling ability was lost and reactors were heavily<br />

damaged. Owing to controlled venting and an unexpected hydrogen explosion, a large amount of radioactive material<br />

was released into the environment. Consequently, many residents living around the NPP were exposed to radiation.<br />

In almost every respect, the consequences of the Chernobyl accident clearly exceeded those of the Fukushima accident.<br />

In both accidents, most of the radioactivity released was due to volatile radionuclides (noble gases, iodine, caesium, and<br />

tellurium) [G. Steinhauser, A. Brandl, T. E. Johnson, 2014].<br />

111<br />

RESEARCH AND INNOVATION<br />

1.2 The context<br />

The objective of the paper is to develop<br />

a domestic user friendly dynamic<br />

radio logical dose and model for accidental<br />

atmospheric release of radionuclides<br />

and normal operation from a<br />

nuclear facility, which has been coupled<br />

with a long-range atmospheric<br />

transport and Gaussian dispersion<br />

model. The research in this study is<br />

based on (i) atmospheric dispersion of<br />

radionuclides, (ii) dose and risk model<br />

development, (iii) validation of the<br />

model with FSAR of typically<br />

WWER-1000 Reactor. Models to<br />

represent the transport of radionuclides<br />

following atmospheric tests<br />

of nuclear weapons were developed<br />

during the 1950s and 1960s. Though<br />

radio nuclides have been released into<br />

the environment during routine operational<br />

conditions of nuclear facilities,<br />

accidents and nuclear weapons tests,<br />

the KIANA Advance Computational<br />

Computer Code model that was developed<br />

for this study was planned to<br />

predict all of radiation doses and risks<br />

in the case of a nuclear accident and<br />

normal operation in nuclear installations.<br />

The novelties in this research are<br />

to couple a KIANA Advance Computational<br />

Computer Code dynamic dose<br />

and risk model with a long-range<br />

atmospheric transport model to predict<br />

the radiological consequences due<br />

to accidental releases and normal<br />

operation in nuclear installations, and<br />

to perform the model simulation for<br />

NPP sites in IRAN territory and with<br />

another site specification data as far as<br />

it can be acquired. Most of the mechanisms<br />

and phenomena considered in<br />

each of the existing dose and risk<br />

calculation and environmental transfer<br />

models have been compiled in the<br />

newly developed single<br />

KIANA Advance Computational<br />

Computer Code to lead detailed modelling.<br />

An uncertainty and sensitivity<br />

analysis can also part of the study to<br />

determine the most influential parameters<br />

and their uncertainties on the<br />

results for users (if applicable). A huge<br />

amount of data, such as radioactivity<br />

concentration in food, pasture and<br />

doses, regarding the consequences<br />

of nuclear power plants’ accidents<br />

and normal conditions in literature<br />

was used for the development of<br />

Computer Code and its validation.<br />

Research and Innovation<br />

Design and Development of a Radio eco logical Domestic User Friendly Code for Calculation of Radiation Doses and Concentration due to Airborn Radio nuclides Release<br />

A. Haghighi Shad, D. Masti, M. Athari Allaf, K. Sepanloo, S.A.H. Feghhi and R. Khodadadi


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

RESEARCH AND INNOVATION 112<br />

1.3 The innovation<br />

The main features of this software and<br />

study can be summarized as follows:<br />

Exposure from all pathways is<br />

included- Ingestion pathways are<br />

modelled in such a detailed way<br />

that, translocation, -transfer between<br />

soil-plant, and feed-animal, food processing<br />

and storage, weathering, and<br />

dilution in the plant are all taken into<br />

account. Time dependency in radionuclide<br />

transfer in the environment<br />

considering food harvesting, sowing<br />

times, feeding regimes, and the<br />

growing up of a person are all taken<br />

into account. Individual doses for<br />

maximum and average individuals<br />

and for four age groups are calculated.<br />

Doses in the case of implementation<br />

of countermeasures are calculated.<br />

Collective doses for big cities can be<br />

calculated. Two different methods for<br />

stochastic risk modelling are applied.<br />

A probabilistic module has also<br />

been developed; namely, uncertainty<br />

analysis can be performed (if applicable).This<br />

study is regarded as unique<br />

since. The model algorithms, which<br />

the KIANA Advance Computational<br />

Computer Code developed for this<br />

study was based on IAEA safety report<br />

series [Müller, H. and Pröhl, G., 1993],<br />

has been modified; the KIANA<br />

Advance Computational Computer<br />

Code to be able to calculate inhalation<br />

doses from resuspension, individual<br />

doses in terms of both average and<br />

maximum habits, collective doses and<br />

late risks, and to utilize the recent<br />

knowledge in the dose and risk assessment<br />

area to the extent possible, such<br />

as dose conversion factors and risk<br />

coefficients etc.<br />

The long-range transport model,<br />

which the code/software developed<br />

for this study was coupled with,<br />

was also upgraded to increase the<br />

number of pollutants modelled to<br />

provide us easiness. Besides, extensive<br />

uncertainty and sensitivity analyses<br />

associated with 96 parameters have<br />

been performed for this study. The<br />

meteorological module in the existing<br />

environmental emergency response<br />

system is associated with 3-day-<br />

Domestic forecast meteorological<br />

data acquired through the State<br />

Meteorological Directorate. The dispersion<br />

model is the Developed AIREM<br />

and DOZAE M model that has the<br />

capability to predict trajectories,<br />

concentration, and deposition patterns<br />

in the case of nuclear accidents and<br />

normal operations. However, doses,<br />

risks, and activities in the food chain<br />

are not calculated with the existing<br />

system in IRAN. Since the newly<br />

developed KIANA Advance Computational<br />

Computer Code for this<br />

study is compatible with the existing<br />

system's dispersion code, it can easily<br />

be integrated into it.<br />

2.1 Atmospheric dispersion<br />

models<br />

Numerous radiation dose calculation<br />

tools have been developed over the<br />

years. They calculate trajectories,<br />

atmospheric transport and dispersion,<br />

age-dependent radiation doses, early<br />

and late health risks, monetary costs<br />

of the accidents, doses in the case<br />

of implementation of emergency<br />

actions, collective health risk, uncertainty<br />

analysis etc. Atmospheric<br />

dispersion methods in these tools<br />

can be based on simple Gaussian or<br />

numerical approaches. Short-range<br />

dispersion models usually use<br />

straight-line Gaussian plume model.<br />

These models are appropriate if the<br />

release is from a source that has<br />

dimensions, which are small compared<br />

to the distances at which concentrations<br />

are to be estimated. For<br />

example, for the distances out to<br />

5-10 km from the source point, if the<br />

terrain is relatively flat and has<br />

uniform surface conditions in all<br />

directions and if the atmospheric<br />

conditions at the time and location of<br />

the release completely control the<br />

transport and diffusion of material<br />

in the atmosphere short-range<br />

atmospheric dispersion models are<br />

preferred. Gaussian dispersion equations<br />

should be used to estimate concentrations<br />

up to the 80 km from the<br />

source under ideal conditions of flat<br />

terrain and no spatial variations of the<br />

wind field. Consequently, for a countrywide<br />

dispersion simulation, due to<br />

topo graphy and dispersion area, the<br />

straight-line Gaussian models can not<br />

be appropriate tools. Therefore, longrange<br />

atmospheric dispersion models<br />

are used in this paper. Dose assessment<br />

methodology in some aforementioned<br />

short range codes neglects<br />

ingestion pathway and calculation<br />

of doses in the late phase of the accident.<br />

These are coupled with simple<br />

radiation dose modelling algorithm,<br />

including only inhalation and external<br />

radiation pathways i.e. HotSpot,<br />

RASCAL and RTARC [Homann, S. G.,<br />

2010, Mcguire, S. A., Ramsdell, Jr., J. V.<br />

and Athey, G. F., 2007, Stubna M. and<br />

Kusovska Z. 1993] All radiation dose<br />

exposure pathways can be seen in<br />

Figure 1.<br />

Since short range codes generally<br />

calculate short-term doses incurred<br />

immediately after the accident and<br />

recommend emergency protective<br />

actions, such as intervention, sheltering<br />

and iodine pills, and long-term<br />

effects incurred from the ingestion<br />

pathway are not generally calculated<br />

with these types of codes. Some of<br />

the codes having a Gaussian plume<br />

methodology calculates ingestion<br />

doses, but not in a dynamic or<br />

| | Fig. 1.<br />

Radiation Dose Exposure Pathways in KIANA Advance Computational Computer Code.<br />

Research and Innovation<br />

Design and Development of a Radio eco logical Domestic User Friendly Code for Calculation of Radiation Doses and Concentration due to Airborn Radio nuclides Release<br />

A. Haghighi Shad, D. Masti, M. Athari Allaf, K. Sepanloo, S.A.H. Feghhi and R. Khodadadi


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

comprehensive way for real time<br />

releases i.e. GENII [Napier 20<strong>02</strong>].<br />

Long- range atmospheric transport<br />

models, on the other hand, generally<br />

focus on the calculation of the trajectories,<br />

atmospheric transport and<br />

dispersion, and are used for real time<br />

emergency preparedness purposes.<br />

These numerical models use multiple<br />

wind measurements in both the horizontal<br />

and vertical directions, and<br />

include terrain effects and vertical<br />

and horizontal wind shear. They also<br />

treat the parameter variables more<br />

realistically, such as surface roughness,<br />

deposition and variable atmospheric<br />

stability. Numerical modelling<br />

is widely used to study long-range<br />

airborne transport and deposition of<br />

radioactive matter after a hypothetical<br />

accident and normal operations.<br />

Ladas, Mesos, and Derma are those<br />

having long-range atmospheric<br />

transport and dispersion algorithm<br />

[ Draxler, R.R., and G.D. Hess, 1997,<br />

Suh et al., 2006, 2008, 2009, Apsimon,<br />

H.M.; Goddard, A.J.H.; Wrigley, J.,<br />

1985 and Sørensen, 1998; Sørensen et<br />

al., 2007]. Generally, these types of<br />

long-range dispersion codes are integrated<br />

with environmental transfer<br />

models to predict activity in the<br />

environment and the resulting doses.<br />

2.2 Radioecological models<br />

Two general classes of radioecological<br />

models have evolved; dynamic (transient)<br />

and equilibrium (steady state).<br />

Both describe the environment in<br />

terms of various „compartments” such<br />

as plant types, animal food products’<br />

types and soil layers. Some environmental<br />

media may be described in<br />

terms of more than one compartment,<br />

such as the roots, branches and trunk.<br />

When the equations are evaluated for<br />

sufficiently long times with unvarying<br />

values of the inputs and rate constants,<br />

the ratios of the concentrations<br />

of the radionuclides in the various<br />

compartments approach constant<br />

values. The system is then considered<br />

to be in equilibrium or in a steady<br />

state. These „quasi-equilibrium models”<br />

do not account for changes in<br />

plant biomass, livestock feeding<br />

regimes, or in growth and differential<br />

uptake of radioactive progeny during<br />

food chain transport. They are generally<br />

not appropriate for the assessment<br />

of critical short-term impacts<br />

from acute fallout events that may<br />

occur during the different times of the<br />

year and for applications related to<br />

the development of criteria for the<br />

implementation of actions. In the late<br />

1970’s the dynamic radioecological<br />

models started to emerge and led to a<br />

number of different such models.<br />

Since dynamic food chain transport<br />

models themselves are normally<br />

rather complex and require significant<br />

computing times most of the codes<br />

[e.g. Slaper et al., 1994, Hermann et<br />

al., 1984, Napier et al., 1988] neglect<br />

radiation exposure changes due to<br />

seasonal variations of radionuclides<br />

in the environment and human<br />

behaviour. For more realistic dose<br />

calculations, time dependency of<br />

the radionuclide transfer processes<br />

should be taken into account, leading<br />

to a dynamic modelling. Lots of radiological<br />

data are necessary for dynamic<br />

ingestion pathway modelling. After<br />

the significant parameters are determined<br />

with respect to their effects on<br />

the results by sensitivity analysis<br />

these data may be derived locally to<br />

lead to realistic modelling, PARATI,<br />

PATWHWAY, Ecosys-87, SPADE<br />

(quasi- equilibrium), COMIDA and<br />

DYNACON are some dynamic dose<br />

models for modelling environmental<br />

transfer of radionuclides in the food<br />

chain [Rochedo et.al. 1996, Whicker<br />

and Kirchner, 1987, Müller, H., Pröhl,<br />

G., 1993, Johnson and Mitchell, 1993;<br />

Mitchell, 1999, Abbott, M.L., Rood,<br />

A.S., 1993, Hwang, W.T., Lee, G.C. Suh,<br />

K.S. E.H. Kim].<br />

Since equilibrium in the model<br />

compartments (between vegetation,<br />

soil, and animal products) is not<br />

reached for a long time, it is essential<br />

to consider seasonality in the growing<br />

cycle of crops, feeding practices of<br />

domestic animals, and dietary habits.<br />

However, because of the temporal<br />

resolution demanded for the output, a<br />

great deal of information is required<br />

as input to this type of model, and<br />

extensive computer resources are<br />

required for the implementation.<br />

By using assumptions of quasiequilibrium<br />

(that is, relatively small<br />

changes from year to year in local<br />

conditions), the dynamic models may<br />

be simplified into equilibrium models.<br />

Knowledge of the contamination level<br />

of radionuclides in foodstuffs, including<br />

crops and animal products is<br />

essential information for deciding the<br />

implementation of protective actions.<br />

The degree of contamination can be<br />

evaluated through a model prediction<br />

from the amount of radionuclides<br />

deposited on the ground, as well as<br />

through direct measurements of<br />

radionuclides in foodstuffs. In developing<br />

systems for emergency preparedness<br />

as well as providing for<br />

rapid decision-making relating to<br />

foodstuffs, the characterization of<br />

action plans based on model predictions<br />

are likely to be appropriate. In<br />

the case of short-term deposition of<br />

radionuclides after a nuclear accident,<br />

the radionuclide concentration in<br />

foodstuffs is strongly dependent on<br />

the date (or season) when the deposition<br />

occurs, and on the time after the<br />

deposition due to factors such as<br />

crop growth and biokinetics of radionuclides<br />

ingested by the animals.<br />

Therefore, these dynamic environmental<br />

transfer models are generally<br />

implemented in a real time emergency<br />

or decision support systems, which<br />

are used before and during an ongoing<br />

emergency and provide sound<br />

basis countermeasures. In some radioecological<br />

models, such as COMIDA,<br />

CRLP and TERNIRBU [Brown, J. and<br />

Simmonds, J., R.,1995, KrcgewskiP.,<br />

1989, Kanyar, B., Fulop N., TERNIRBU,<br />

1996] soil compartment is modelled<br />

in such a way that it is divided into<br />

many layers: surface layer, root layer,<br />

and deep soil layer, etc.. The code<br />

developed for this study took AIREM,<br />

DOZAE M & S. R.S of IAEA models as<br />

reference. The data library for unlimited<br />

isotopes is available in the new<br />

software (sub routines). All natural<br />

phenomena important for the ingestion<br />

pathway modelling is taken into<br />

consideration in the new algorithm<br />

and model. Whereas, time dependent<br />

translocation, layered soil compartment,<br />

wet interception, and mushroom<br />

pathway are not available in the<br />

current model. Generally, the computer<br />

models developed for the prediction<br />

of routine releases from NPPs<br />

are based on the annual average concentrations<br />

of radionuclides in air<br />

and on the ground. However, for NPP<br />

routine atmospheric releases a<br />

dynamic model coupled with a longrange<br />

transport code was developed<br />

in another study [Kocar, C., 2003]. In<br />

the current study, to address the<br />

unique features of modelling operational<br />

radiological consequences of<br />

nuclear power plants, a few new<br />

algorithm based on the dynamic<br />

radioecological model had been<br />

considered. Different from the aforementioned<br />

dynamic model [Müller, H.<br />

and Pröhl, G., 1993], transfer mechanisms<br />

of C-14 and H-3 were coded and<br />

multi-location food supply and interregional<br />

moves of people in the computational<br />

domain were permitted.<br />

In this study, inhalation doses from<br />

both passages of the cloud and resuspension<br />

of deposited activity are<br />

calculated and accidental releases are<br />

simulated, but the previous one is for<br />

operational releases are modelled and<br />

RESEARCH AND INNOVATION 113<br />

Research and Innovation<br />

Design and Development of a Radio eco logical Domestic User Friendly Code for Calculation of Radiation Doses and Concentration due to Airborn Radio nuclides Release<br />

A. Haghighi Shad, D. Masti, M. Athari Allaf, K. Sepanloo, S.A.H. Feghhi and R. Khodadadi


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

RESEARCH AND INNOVATION 114<br />

| | Fig. 2.<br />

Summary of Code Algorithms.<br />

H-3 and C-14 releases which are of<br />

great significance for operational<br />

releases are modelled. In this study,<br />

individual doses are calculated for<br />

two different habits of the people in<br />

term of food consumption and gamma<br />

reduction.<br />

3.1 KIANA advance<br />

computational computer<br />

code structure<br />

A deterministic dose calculation<br />

model called KIANA Advance Computational<br />

Computer Code has been<br />

developed for this study. For the dose<br />

assessment, all exposure pathways<br />

have been implemented as follows:<br />

Transfer of radionuclides through<br />

food chains and the subsequent<br />

internal exposures of humans due to<br />

ingestion of contaminated foodstuffs-<br />

Internal exposure due to inhalation of<br />

radionuclides during passage of cloud<br />

and from resuspension of deposited<br />

radionuclides- External exposure<br />

from radionuclides in the passing<br />

cloud- External exposure from radionuclides<br />

deposited on the ground. The<br />

design of the KIANA Code is flexible<br />

such that it can be adopted anywhere<br />

for any nuclear power plant/nuclear<br />

installation site with suitable modifications<br />

to the database.<br />

3.2 Ingestion pathway<br />

Ingestion pathway calculations in<br />

KIANA Advance Computational<br />

Computer Code take into account<br />

the following process and data:<br />

Yield of grass and agricultural food<br />

products. Harvesting and sowing time<br />

of grass and agricultural products.<br />

Translocation within plants. Interception.<br />

Weathering from plant surfaces.<br />

Dilution of radionuclide concentrations<br />

due to plant growth. Uptake<br />

by plant roots. Migration within the<br />

soil and Plant contamination due to<br />

resuspended soil. Different livestock<br />

feeding regimes. Storage times for<br />

fodder and human food products.<br />

Changes in radionuclide concentrations<br />

due to food processing. Age<br />

dependent ingestion dose coefficients<br />

for the public are taken from ICRP 72<br />

[1996]. Dose coefficients for 3 months<br />

infant, 5 year old children, 15 years<br />

old teen and adult are used. ICRP<br />

ingestion dose conversion factors take<br />

into account integration period of<br />

50 years for adults and 70 year for<br />

children. Input data to the ingestion<br />

modelling is the time integrated<br />

air concentrations, and deposited<br />

activity from any dispersion model or<br />

measured data. Ingestion of tap water<br />

and aquatic food products are not<br />

considered in KIANA Advance Computational<br />

Computer Code.<br />

3.3 Activity concentration<br />

of plant products<br />

The contamination of plant products<br />

as a function of time results from the<br />

direct contamination of the leaves and<br />

the activity transfer from the soil by<br />

root uptake and resuspension:<br />

C i (t) = C i,f (t) + C i,r (t)<br />

C i (t); total contamination<br />

of plant type i,<br />

C i,f (t); contamination of plant type i<br />

due to foliar uptake,<br />

Ci,r(t); contamination of plant type i<br />

due to root uptake<br />

Pasture and 13 different plant products,<br />

i.e. corn cobs, spring and winter<br />

wheat, spring and winter barley, rye,<br />

fruits, berries, and root, fruit and leafy<br />

vegetables, potatoes and beet can be<br />

modelled by KIANA Advance Computational<br />

Computer Code.<br />

3.4 Foliar uptake<br />

of radionuclides:<br />

Calculation of the contamination of<br />

plants must distinguish between<br />

plants that are used totally (leafy vegetables<br />

and grass) and plants of which<br />

only a special part is used. The activity<br />

concentration at time after the deposition<br />

is determined by the initial contamination<br />

of the plant and activity<br />

loss due to weathering effects (rain,<br />

wind) and radioactive decay and<br />

growth dilution. For plants that are<br />

totally consumed growth, excluding<br />

pasture grass, growth is implicitly<br />

considered because the activity deposited<br />

onto leaves is related to the<br />

yield at harvest. Interception factor is<br />

defined as the ratio of the activity initially<br />

retained by the standing vegetation<br />

immediately subsequent to the<br />

deposition event to the total activity<br />

deposited. Radionuclides to agricultural<br />

plants may be intercepted by dry<br />

process, wet process, or a combination<br />

of both. The interception fraction is<br />

dependent on the plant intensity in<br />

the area, stage of development of the<br />

plant, and generally leaf area of the<br />

crops. In the present model, a single<br />

coefficient was used and interception<br />

factors for grass and other plants were<br />

taken from DoseCAL code; the interception<br />

factor for grass and, fruits and<br />

vegetables is assumed to be 0.3 and<br />

for the grain and cereals it is 0.005.<br />

The activity concentration at the time<br />

of harvest is given<br />

(3.8)<br />

C i,f (t); concentration of activity in<br />

plant type i at time of harvest,<br />

f i ; interception factor<br />

for plant type i,<br />

A i ; total deposition (Bq.m –2 ) of<br />

plant type i at time of harvest,<br />

λ w ; loss rate (d –1 )<br />

due to weathering,<br />

λ r ; decay rate (d –1 ),<br />

Δt; time span between deposition<br />

and harvest (d)<br />

The approach for pasture grass is<br />

different because of its continuous<br />

harvest. Here, the decrease in activity<br />

due to growth dilution is explicitly<br />

considered.<br />

C g,f (t); activity concentration<br />

(Bq.kg –1 ) in grass at time t<br />

after deposition,<br />

f g ; interception factor for grass,<br />

A g ; total activity deposited onto<br />

grass (Bq.m –2 )<br />

Y g ; yield of grass at time of<br />

deposition (kg.m –2 )<br />

a; fraction of activity translocated<br />

tot the root zone,<br />

λ b ; dilution rate by increase<br />

of biomass (d –1 ),<br />

λ t ; rate of activity decrease (d –1 )<br />

due to translocation to the<br />

root zone<br />

For the weathering rate constant λw; a<br />

value equivalent to a half-life 14 d is<br />

taken from Farmland code (NRPB,<br />

1995) and for rate of activity decrease<br />

due to translocation to the root zone<br />

λt; 1.16x10-2 d-1 with a contribution<br />

fraction a= 0.05 using different measurement<br />

of grass contamination after<br />

the Chernobyl accident are assumed<br />

[Pröhl, 1990]. For plants that are only<br />

partly used for animal feeding or<br />

human consumption the translocation<br />

Research and Innovation<br />

Design and Development of a Radio eco logical Domestic User Friendly Code for Calculation of Radiation Doses and Concentration due to Airborn Radio nuclides Release<br />

A. Haghighi Shad, D. Masti, M. Athari Allaf, K. Sepanloo, S.A.H. Feghhi and R. Khodadadi


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

from leaves to the edible part of the<br />

plant has to be considered. This process<br />

strongly depends on the physiological<br />

behaviour of the element<br />

considered. It is important for mobile<br />

elements such as caesium, iodine,<br />

tellurium whereas for immobile<br />

elements including strontium, barium,<br />

zirconium, niobium, ruthenium,<br />

cerium, plutonium only direct deposition<br />

onto edible parts of the plants<br />

play role. Translocation process is<br />

quantified by translocation factor Ti,<br />

which is defined as the fraction of the<br />

activity deposited on the foliage being<br />

transferred to the edible parts of the<br />

plant until<br />

harvest. It is dependent on the<br />

element, plant type and time between<br />

deposition and harvest. Translocation<br />

factors for agricultural food products<br />

for caesium, strontium and other<br />

elements were taken from IAEA<br />

TRS-472 (2010). Translocation factors<br />

for only the ripening stage is applied<br />

in KIANA Advance Computational<br />

Computer Code.<br />

3.5 Root uptake<br />

of radionuclides<br />

The estimation of the root uptake of<br />

radionuclides assumes that the radionuclides<br />

are well mixed within the entire<br />

rooting zone. The concentration<br />

of activity due to root uptake is calculated<br />

from the concentration of activity<br />

in the soil using transfer factor TFi<br />

that gives the ratio of concentration of<br />

activity in plants (fresh weight) and<br />

soil (dry weight)<br />

C i,r (t) = TF i C s (t)<br />

C i, r (t); concentration of activity<br />

(Bq/kg) in plant type i due to<br />

root uptake at time t after the<br />

deposition,<br />

TF i ; soil-plant transfer factor for<br />

plant type i,<br />

Cs(t); concentration of activity<br />

(Bq/kg) in the root zone of<br />

soil at time t<br />

The soil conditions which soil-plant<br />

transfer factors are based are often<br />

characterised by a low pH value together<br />

with a high organic content,<br />

and low contents of clay, potassium<br />

and calcium. Such soils are frequently<br />

found in upland areas, Scandinavia,<br />

and parts of Eastern Europe. (Pröhl,<br />

G., and Müller, H., 1993) The concentration<br />

of activity in the root zone of<br />

soil is given by;<br />

A s ; total deposition to soil<br />

(Bq.m –2 )<br />

L; depth of root zone (m)<br />

ρ; density of soil (kg.m –3 )<br />

λ s ; rate of activity decrease due<br />

to migration out of the root<br />

zone<br />

λ r ; rate of fixation (d –1 )<br />

The migration rate λ s is estimated<br />

according to;<br />

v a ; velocity of percolation water<br />

in soil (m.a –1 )<br />

K d ; distribution coefficient<br />

(cm 3 .g –1 )<br />

θ; water content of soil (g.g –1 )<br />

3.6 Contamination<br />

of animal products<br />

The contamination of animal products<br />

results from the activity intake of<br />

the animals and the kinetics of the<br />

radionuclides within the animals.<br />

Inhalation of radionuclides by the<br />

animals is not considered; this pathway<br />

may be relevant for milk contamination<br />

in certain cases, but it is<br />

unimportant for resulting doses. The<br />

amount of activity ingested by the<br />

animals is calculated from the concentration<br />

of activity in the different<br />

foodstuffs and the feeding rates;<br />

A a,m (t); activity intake rate of the<br />

animal m (Bq.d –1 ),<br />

K m ; number of different feedstuffs<br />

fed to the animal m,<br />

C k (t); activity concentration<br />

(Bq.kg –1 ) in feedstuffs k,<br />

I k,m (t); feeding rate (kg.d –1 ) for<br />

feedstuffs k and animal m<br />

Soil ingestion is also considered in<br />

KIANA Advance Computational Computer<br />

Code. Soil intake of animals<br />

varies widely depending on the<br />

grazing management and the condition<br />

of the pasture. If the feeding of<br />

mechanically prepared hay and silage<br />

during winter and an intensive<br />

grazing regime on well fertilized<br />

pasture are assumed a mean annual<br />

intake of 2.5% of the grass dry matter<br />

intake seems to be appropriate. This<br />

nuclide independent value is equivalent<br />

to soil-plant transfer factor of<br />

5x10-3 and it is added to the transfer<br />

and resuspension factor in KIANA<br />

Advance Computational Computer<br />

Code. This means that for all elements<br />

with a transfer factor lower than this<br />

value, soil eating is the dominating<br />

long term pathway for the contamination<br />

for milk and meat from grazing<br />

cattle, presuming that resorption in<br />

the gut is the same for soil-bound and<br />

plant incorporated radionuclides.<br />

Seven different animal products,<br />

namely cow, sheep and goat milk, and<br />

lamb, beef cattle, egg and chicken,<br />

can be modelled by KIANA Advance<br />

Computational Computer Code.<br />

Transfer of radionuclides from fodder<br />

into animal products is calculated as<br />

follows:<br />

C m (t); activity concentration<br />

in animal product m at time t,<br />

TF m ; transfer factor (d.kg –1 )<br />

for animal product m,<br />

j; number of biological transfer<br />

rates,<br />

a mj ; fraction of biological transfer<br />

rates,<br />

λ b,mj ; biological transfer rate j (d –1 )<br />

for animal product m<br />

For sheep and goat milk transfer<br />

factors 10 times higher than for cow<br />

milk are assumed. For lamb, goat’s<br />

meat, and chicken, the transfer was<br />

estimated from the feed-beef transfer<br />

factor by applying correction factors<br />

for the lower body mass. Correction<br />

factors are 3 for lamb, and goat’s meat<br />

and 100 for chicken. [Müller, H. and<br />

Pröhl, G., 1993] Biological turnover<br />

rates of animal products were taken<br />

from DOZAE M, AIREM and DoseCAL.<br />

3.7 The processing and<br />

storage of foodstuffs<br />

The processing and storage of foodstuffs<br />

in order to take advantage of the<br />

radioactive decay and dilution during<br />

these processes are taken into account<br />

in the model. The enrichment of minerals<br />

in the outer layers of grains and<br />

the fractionation in the milling products<br />

is considered. Besides, the radioactive<br />

decay during processing and<br />

storage is taken into account. The storage<br />

presumes the stability of the foodstuffs<br />

or the possibility to convert the<br />

foodstuffs into stable products. Storage<br />

times are considered to be mean<br />

time between the harvest and beginning<br />

of product consumption. Concentration<br />

of activity in products is<br />

calculated from the raw product by<br />

the following relation:<br />

C k (t) = C ko (t–t pk )P k exp(–λ t pk )<br />

RESEARCH AND INNOVATION 115<br />

Research and Innovation<br />

Design and Development of a Radio eco logical Domestic User Friendly Code for Calculation of Radiation Doses and Concentration due to Airborn Radio nuclides Release<br />

A. Haghighi Shad, D. Masti, M. Athari Allaf, K. Sepanloo, S.A.H. Feghhi and R. Khodadadi


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

RESEARCH AND INNOVATION 116<br />

| | Fig. 3.<br />

Code Algorithms of contamination of plant products as a function of time results from the direct contamination of the leaves and the activity transfer from the soil<br />

by root uptake and re-suspension that used in construction of KIANA Advance Computational Computer Code.<br />

| | Fig. 4.<br />

Code Algorithms calculation of Inhalation doses for each incremental time<br />

step (in days) that used in construction of KIANA Advance Computational<br />

Computer Code.<br />

C k (t); activity concentration<br />

(Bq/kg) in product k ready<br />

for consumption at time t,<br />

C ko ; activity concentration<br />

(Bq/kg) in raw product<br />

at time t,<br />

P k ; processing factor<br />

for product k,<br />

λ r ; radioactive decay constant<br />

(d –1 ),<br />

t pk ; storage and processing<br />

time (d) for product k<br />

3.8 Activity intake and<br />

exposure<br />

The intake of activity by humans is<br />

calculated from the time-dependent<br />

concentrations of activity in foodstuffs<br />

and the human consumption rate:<br />

A h (t); human intake rate (Bq.d –1 )<br />

of activity,<br />

C k (t); concentration of activity<br />

(Bq.kg –1 ) of foodstuff k,<br />

V k (t); consumption rate (kg.d –1 )<br />

of foodstuff k<br />

The foodstuffs are assumed to be<br />

locally produced. Food consumption<br />

data that is very important for<br />

calculating dose exposure by ingestion<br />

pathway is different depending<br />

on where people live. Country specific<br />

data on consumption of food products<br />

have been used to lead to realistic<br />

modelling. The dose Ding(t) due to<br />

ingestion of contaminated foodstuffs<br />

within time t after the deposition, is<br />

given by the following;<br />

D ing (t); ingestion dose (Sv)<br />

DF; age dependent dose factor<br />

for ingestion (Sv.Bq –1 )<br />

4 Total dose calculation<br />

KIANA Advance Computational Computer<br />

Code calculates yearly doses for<br />

each age group and for each sector –<br />

segment after the accident. Agricultural<br />

food products' activities are<br />

calculated at each year's harvest,<br />

grass and animal products' activities<br />

are calculated on a monthly basis.<br />

All aforementioned pathways are<br />

included in dose calculations as shown<br />

below:<br />

Dose total = Dose inhalation + Dose ingestion +<br />

Dose cloudshine + Dose groundshine<br />

Research and Innovation<br />

Design and Development of a Radio eco logical Domestic User Friendly Code for Calculation of Radiation Doses and Concentration due to Airborn Radio nuclides Release<br />

A. Haghighi Shad, D. Masti, M. Athari Allaf, K. Sepanloo, S.A.H. Feghhi and R. Khodadadi


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

RESEARCH AND INNOVATION 117<br />

| | Fig. 5.<br />

Code Algorithms calculation of Activity concentration of plant products Root uptake of radionuclides that used in construction of KIANA Advance Computational<br />

Computer Code.<br />

| | Fig. 6.<br />

Code Algorithms concentration, activity intake rate of the animal m (Bq. d -1 ), that used in construction of KIANA Advance Computational Computer Code.<br />

Dose total ; total dose (Sv)<br />

Dose inhalation ; inhalation dose (Sv)<br />

Dose ingestion ; ingestion dose (Sv)<br />

Dose cloudshine ; cloudshine dose (Sv)<br />

A person is assumed to be as an infant<br />

up to 1 year, as a child up to 9 years, as<br />

teen up to 16 years and as an adult up<br />

to 70 years; namely when calculating<br />

long term doses after the accident<br />

growing up of a person is taken into<br />

account in terms of his/her food<br />

consumption habits, sensitivity to<br />

doses and occupancy factors.<br />

4.1 Calculation of collective<br />

doses<br />

The impact of an accident on the<br />

population as a whole depends not<br />

only on the deposition, atmospheric<br />

activity levels and dose obtained,<br />

but also on the population living in<br />

Research and Innovation<br />

Design and Development of a Radio eco logical Domestic User Friendly Code for Calculation of Radiation Doses and Concentration due to Airborn Radio nuclides Release<br />

A. Haghighi Shad, D. Masti, M. Athari Allaf, K. Sepanloo, S.A.H. Feghhi and R. Khodadadi


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

RESEARCH AND INNOVATION 118<br />

| | Fig. 7.<br />

Code Algorithms of Concentration of activity in products is calculated from<br />

the raw product that used in construction of KIANA Advance Computational<br />

Computer Code.<br />

| | Fig. 8.<br />

Code Algorithms intake of activity by humans is calculated from the<br />

time-dependant concentrations of activity in foodstuffs and the human<br />

consumption rate that used in construction of KIANA Advance<br />

Computational Computer Code (upper part of the diagram).<br />

Code Algorithms for dose Ding(t) due to ingestion of contaminated<br />

foodstuffs within time t after the deposition, is given by the following<br />

that used in construction of KIANA Advance Computational Computer<br />

Code (lower part of the diagram).<br />

that particular area. For example<br />

the deposition, atmospheric activity<br />

levels, dose obtained and individual<br />

health risk, due to any NPP accident,<br />

may be very high, but these high<br />

values may not mean anything if there<br />

is no one living there. Consequently,<br />

better representation of the collective<br />

doses or risk of an accident, nuclear<br />

and nonnuclear, can be obtained by<br />

multiplying the individual dose or<br />

health risk by the number of people<br />

living in the receptor. For this study,<br />

average values all over the geographical<br />

regions were taken into<br />

account, since data does not vary<br />

considerably over the regions. On<br />

the other hand. Transfer factors for<br />

animal- feeds and soil-plants, and fixation<br />

rates, distribution coefficients,<br />

translocation factors, dose conversion<br />

factors and metabolic turnover rates<br />

in animals for all related isotopes, and<br />

processing factors and storage days<br />

for food products, weathering rates,<br />

interception factors and soil density,<br />

water content of soil, percolation<br />

water velocity, dilution factor of<br />

the grass, depth of root zone, the<br />

references in which Cs-137 default<br />

values were taken for validation study,<br />

were used in KIANA Advance Computational<br />

Computer Code during<br />

simulation of the case studies. Since<br />

most of these data are not dependent<br />

on location.<br />

5 Result and discussions<br />

Dispersion of radionuclides is also an<br />

application area of KIANA Advance<br />

Computational Computer Code. User<br />

supplied inputs for KIANA Advance<br />

Computational Computer Code calculations<br />

are pollutant species<br />

characteristics, emission parameters,<br />

gridded meteorological fields and<br />

output deposition grid definitions.<br />

The horizontal deformation of the<br />

wind field, the wind shear, and the<br />

vertical diffusivity profile are used to<br />

compute the dispersion rate. Gridded<br />

meteorological data are required for<br />

regular time intervals. The meteorological<br />

data fields may be provided on<br />

one of the different vertical coordinate<br />

system: Pressure-sigma, pressure<br />

absolute, terrain-sigma or a hybrid<br />

absolute-pressure-sigma The doses<br />

and time dependant radioactivity concentration<br />

values in the food products<br />

and pasture grass predicted by KIANA<br />

Advance Computational Computer<br />

Code have been compared with those<br />

of different codes (AIREM,DOZA)<br />

which participated in assessment task,<br />

and data measured in Boshehr, and<br />

Finland after Chernobyl accident.<br />

Radionuclide<br />

Activity (Bq)<br />

Sr-89<br />

8.5E+09<br />

Kr-90<br />

6.7E+13<br />

Rb-90<br />

6.4E+13<br />

Sr-90<br />

2.2E+07<br />

Sr-91<br />

2.6E+11<br />

Sr-92<br />

2.1E+11<br />

Mo-99<br />

1.1E+09<br />

Ru-103<br />

9.3E+08<br />

Ru-106<br />

1.3E+07<br />

Ru-106<br />

1.3E+07<br />

Ru-106<br />

1.3E+07<br />

Te-131<br />

9.3E+10<br />

I-131 3.1E+13<br />

Te-132<br />

1.2E+10<br />

I-132 8.3E+13<br />

Te-133<br />

1.6E+11<br />

I-133 6.8E+13<br />

Xe-133<br />

1.7E+13<br />

I-134 6.3E13<br />

Cs-134<br />

1.8E+12<br />

I-135 5.1E+13<br />

Xe-135<br />

1.1E+13<br />

Cs-137<br />

2.8E+12<br />

Xe-138<br />

4.6E+13<br />

C-138 4.9E+13<br />

Ba-139<br />

9.9E+11<br />

Ba-140<br />

1.1E+10<br />

La-140<br />

1.4E+09<br />

141-Ce<br />

1.8E+09<br />

Ce-144<br />

2.0E+08<br />

Br-84<br />

1.5E+13<br />

Kr-85m<br />

1.2E+13<br />

Kr-85<br />

3.3E+09<br />

Br-87<br />

3.7E+13<br />

Kr-87<br />

3.9E+13<br />

Kr-88<br />

4.9E+13<br />

Rb-88<br />

4.9E+13<br />

Kr-89<br />

6.7E+13<br />

Rb-89<br />

7.1E+13<br />

Pr-144<br />

1.8E+08<br />

Zr-95<br />

1.2E+09<br />

Nb-95<br />

1.2E+07<br />

Zr-97<br />

7.4E+10<br />

Nb-97<br />

6.7E+10<br />

Na-24<br />

2.7E+11<br />

K-42 1.2E+12<br />

Fe-59<br />

1.9E+07<br />

Co-58<br />

7.4E+07<br />

Cr-51<br />

1.4E+08<br />

Mn-54<br />

1.9E+07<br />

Co-60<br />

2.0E+08<br />

Activities (Bq)<br />

I-131 3.1E+11<br />

I-132 8.4E+11<br />

I-133 6.9E+11<br />

I-134 6.3E+11<br />

I-135 5.1E+11<br />

| | Tab. 1.<br />

Radionuclide release to environment after<br />

severe accident at typically WWER-1000 NPP<br />

such as Boushehr.<br />

Those codes are dynamic (timedependent),<br />

and only one of them; i.e.<br />

DoseCAL, is quasi-equilibrium. Since<br />

KIANA Advance Computational Computer<br />

Code is developed as dynamic<br />

software (such as DoseCAL), only<br />

dynamic codes' results are presented<br />

for comparison. KIANA Advance<br />

Computational Computer Code has a<br />

Research and Innovation<br />

Design and Development of a Radio eco logical Domestic User Friendly Code for Calculation of Radiation Doses and Concentration due to Airborn Radio nuclides Release<br />

A. Haghighi Shad, D. Masti, M. Athari Allaf, K. Sepanloo, S.A.H. Feghhi and R. Khodadadi


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

RESEARCH AND INNOVATION 119<br />

| | Fig. 9.<br />

Code Algorithms for calculation of ground level air concentration at downwind distance x in the sector) p (Bq/m3), when the source and receptor on the same<br />

building surface that used in construction of KIANA Advance Computational Computer Code.<br />

capability to make simulation with<br />

seven pollutants at a time at most.<br />

Since some more radionuclides<br />

considered being most important in<br />

terms of their effects in the environment<br />

are used to represent accidental<br />

release of radionuclides in the literature,<br />

HYSPLIT model's source code<br />

has been modified to simulate more<br />

pollutants to provide us easiness for<br />

this study.<br />

In this study, dry deposition velocity<br />

is assumed to be a constant for<br />

each radionuclide and surface type.<br />

the dry deposition velocity values for<br />

agricultural surface type were used in<br />

our simulations. To strengthen our<br />

assumption, size of the particles<br />

released into environment in the case<br />

of a nuclear accident was also investigated.<br />

Release height is another<br />

important parameter for subsequent<br />

dispersion modelling in KIANA<br />

Advance Computational Computer<br />

Code. Literature studies show that<br />

variations of the initial plume rise<br />

below the mixing height only slightly<br />

affect the results outside the local<br />

scale, whereas plume rise above that<br />

level led to significantly changed patterns<br />

with relatively little depositions<br />

on the local and meso-scales. Thus,<br />

a release into the atmospheric<br />

boundary level compared with a<br />

release to the free troposphere leads<br />

to large differences in the deposition<br />

patterns and lifetimes (a week or<br />

more) of radionuclides within the<br />

atmosphere. Release height was<br />

assumed as a line source between<br />

50-100 meter considering all the accident<br />

type, release points in the reactor<br />

and plume rise. In 1986, there was a<br />

recommendation to postpone the<br />

open field sowing of lettuce, spinach<br />

and other fast growing vegetables.<br />

Although it is not clear to what extent<br />

this recommendation was implemented<br />

across all regions, the fact<br />

that KIANA Advance Computational<br />

Computer Code did not account for<br />

any delay in sowing. However, only<br />

root uptake for leafy vegetables was<br />

taken into account in DoseCAL. Leafy<br />

vegetables activities predicted by<br />

KIANA Advance Computational Computer<br />

Code are within the uncertainty<br />

band of the measured values and the<br />

best of all other code results. The<br />

probability for T-test for is 0.834,<br />

which is close to one. The differences<br />

between the predictions of the codes<br />

which participated in VAMP exercise,<br />

may be raised from misinterpretation<br />

of site-specific information; namely<br />

taking into account different assumptions,<br />

or using different soil-plant and<br />

feed-animal transfer factors as stated<br />

in IAEA TECDOC-904 (1996). Inhalation<br />

and external doses predicted<br />

by KIANA Advance Computational<br />

Computer Code as the as the DoseCAL<br />

calculations are rather consistent<br />

compared to other codes' predictions.<br />

Ingestion doses predicted by KIANA<br />

Advance Computational Computer<br />

Code, on the other hand, is lower<br />

compared to the other codes. Since in<br />

ingestion module of KIANA Advance<br />

computational Computer Code, mushroom,<br />

fish, game animals are not taken<br />

into account, whereas other food<br />

products, i.e. fruits, root and fruit vegetables,<br />

eggs have been considered as<br />

default. it is almost equal to beef consumption,<br />

and most of the ingestion<br />

doses calculated by most of the models<br />

participated in validation exercise<br />

were incurred from fish consumption.<br />

Hence, the difference in ingestion<br />

dose prediction in KIANA Advance<br />

Computational Computer Code can be<br />

attributed to fish pathway. Ingestion<br />

doses are highly dependent on consumption<br />

rates as seen from the differences<br />

between the doses for average<br />

and maximum individuals. Inhalation<br />

doses are the highest for the children,<br />

though the highest inhalation DCFs<br />

are of infants, breathing rates for<br />

the children are higher than for the<br />

infants. Inhalation dose for teens and<br />

Research and Innovation<br />

Design and Development of a Radio eco logical Domestic User Friendly Code for Calculation of Radiation Doses and Concentration due to Airborn Radio nuclides Release<br />

A. Haghighi Shad, D. Masti, M. Athari Allaf, K. Sepanloo, S.A.H. Feghhi and R. Khodadadi


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

RESEARCH AND INNOVATION 120<br />

adults are lower than children, since<br />

DCF’s for radioisotopes considered in<br />

case study for children are higher than<br />

those for adults except caesium isotopes.<br />

External doses are calculated<br />

for infants and others (child, teen and<br />

adult). Although DCF’s for infants are<br />

1.5 times higher than the others, the<br />

correction factor for shielding is lower<br />

for infants than others, hence external<br />

doses are lower for infants. External<br />

ground doses are lower for infants<br />

too, as far as the years passed after the<br />

accident is concerned. In the case of<br />

implementation of countermeasures<br />

on food consumption restrictions in<br />

the first year after the accident, the<br />

ingestion and total doses for average<br />

individuals for all age groups can be<br />

predicted by KIANA Advance computational<br />

Computer Code. . the most<br />

dose contributing isotopes are Cs-134,<br />

Cs-137 and I-131 in the first year after<br />

the accident. In the long term, Cs-134<br />

and Cs-137 (Table 1) remain in the<br />

environment due to their long radioactive<br />

half-lives. The dose consequence<br />

of Xe-133 is the least amongst<br />

others due to its very short half-life,<br />

i.e. 5.25 days and its inertness. Lifetime<br />

doses incurred from Cs-137,<br />

Cs-134 and I-131 are more than 95%<br />

of total doses. Ingestion doses are the<br />

highest for the infant, child, adult and<br />

teen; respectively in the first year after<br />

the accident since the ingestion DCF<br />

for I-131 for the infants is the highest.<br />

Infant ingestion doses remain the<br />

highest as years pass after the accident,<br />

since infant's growing up is<br />

taken into account and their food<br />

consumption increases when they are<br />

growing.<br />

References<br />

| | Abbott, M.L., Rood, A.S., COMIDA,<br />

A Radionuclide Food Chain Model for<br />

Acute Fallout Deposition, 1993.<br />

| | Abbott, M.L., Rood A.S., Comida: A<br />

radionuclide food chain model for acute<br />

fallout 6825 PNNL-14321 deposition,<br />

Health Phys 66: 17–29, 1994.<br />

| | Absalom JP, Young SD, Crout NMJ,<br />

Radiocaesium fixation dynamics:<br />

Measurement in six Cumbrian soils.<br />

European Journal of Soil Science<br />

46:461-469,1995.<br />

| | INTERNATIONAL ATOMIC ENERGY<br />

AGENCY. Generic Models for Use in<br />

Assessing the Impact of Discharges of<br />

Radioactive Substances to the<br />

Environment. Safety Report Series<br />

No 19, Vienna (2001).<br />

| | ANL/EAD-4, User’s Manual for RESRAD<br />

Version 6, 2001.Anspaugh, L.R., Shinn,<br />

J.H., Phelps, P.L., Kennedy, N.C., Resuspension<br />

and redistribution of plutonium<br />

in soils, Health Phys. 29 (1975) 571–582.<br />

| | Apsimon, H.M.; Goddard, A.J.H.;<br />

Wrigley, J., Long-range atmospheric<br />

dispersion of radioisotopes. The MESOS<br />

model. Atmospheric Environment<br />

(1967) vol. 19 issue 1 1985. p. 99-111.<br />

| | ARGOS home page,<br />

http://www.pdc-argos.com/<br />

[last accessed on 1 st of August, 2014]<br />

| | Baklanov A., Sorensen J.H.,<br />

Parameterization of Radionuclide<br />

Deposition in Atmospheric Long Range<br />

Transport Modeling, 2000.<br />

| | Bauer, L.R., and Hamby, D.M.: 1991,<br />

Relative Sensitivities of Existing and<br />

Novel Model Parameters in<br />

Atmospheric Tritium Dose Estimates,<br />

Rad. Prot. Dosimetry. 37, 253-260.<br />

| | Bellman, R., and Astrom, K.J.: 1970,<br />

On Structural Identifiability, Math.<br />

Biosci. 7, 329-339.<br />

| | Bergstroem, U., Nordlinder, S., Studsvik<br />

Eco and Safety AB, Nykoeping, Sweden,<br />

1981.<br />

| | Box, G.E.P., Hunter, W.G., and Hunter,<br />

J.S.: 1978, Statistics for Experimenters:<br />

an Introduction to Design, Data<br />

Analysis, and Model Building. John<br />

Wiley & Sons. New York.<br />

| | Breshears, D.D.: 1987, Uncertainty and<br />

sensitivity analyses of simulated<br />

concentrations of radionuclides in milk.<br />

Fort Collins, CO: Colorado State<br />

University, MS Thesis, pp. 1-69.149<br />

| | Brown, J. and Simmonds, J., R.,<br />

FARMLAND: A Dynamic Model for the<br />

Transfer of Radionuclides through<br />

Terrestrial Foodchains, 1995.<br />

| | Ciffroy, P., Siclet, F., Damois, C., Luck, M.,<br />

Duboudin, C., A dynamic model for<br />

assessing radiological consequences of<br />

routine releases in the Loire river:<br />

Parameterisation and uncertainty/<br />

sensitivity analysis, Journal of Environmental<br />

Radioactivity 83 (2005) 9-48.<br />

| | Christoudias, T. and Lelieveld, J.,<br />

Modelling the global atmospheric<br />

transport and deposition of radionuclides<br />

from the Fukushima Daiichi<br />

nuclear accident, Atmos. Chem. Phys.,<br />

13, 1425–1438, 2013.<br />

| | Conover, W.J.: 1980, Practical Nonparametric<br />

Statistics. 2 nd edn. John<br />

Wiley & Sons, New York.<br />

| | Cox, N.D.: 1977, Comparison of Two<br />

Uncertainty Analysis Methods, Nuc. Sci.<br />

and Eng. 64, 258-265.<br />

| | Crick, M.J., Hill, M.D. and Charles, D.:<br />

1987, The Role of Sensitivity Analysis in<br />

Assessing Uncertainty. In: Proceedings<br />

of an NEA Workshop on Uncertainty<br />

Analysis for Performance Assessments<br />

of Radioactive Waste Disposal Systems,<br />

Paris, OECD, pp. 1-258.<br />

| | Cunningham, M.E., Hann, C.R., and<br />

Olsen, A.R.: 1980, Uncertainty Analysis<br />

and Thermal Stored Energy Calculations<br />

in Nuclear Fuel Rods, Nuc. Technol. 47,<br />

457-467.<br />

| | Cukier, R.I., Fortuin, C.M., Shuler, K.E.,<br />

Petschek, A.G. and Schaibly, J.H.: 1973,<br />

Study of the Sensitivity of Coupled<br />

Reaction Systems to Uncertainties in<br />

Rate Coefficients. I. Theory Z Chem.<br />

Phys. 59, 3873-3878.<br />

| | Demiralp, M., and Rabitz, H.: 1981,<br />

Chemical Kinetic Functional Sensitivity<br />

Analysis: Elementary Sensitivities,<br />

J. Chem. Phys. 74, 3362-3375.<br />

| | Downing, D.J., Gardner, R.H., and<br />

Hoffman, EO.: 1985, An Examination of<br />

Response-Surface Methodologies for<br />

Uncertainty Analysis in Assessment<br />

Models, Technometrics. 27, 151-163.<br />

| | Draxler, R.R., and G.D. Hess, 1997:<br />

Description of the HYSPLIT_4 modeling<br />

system. NOAA Tech. Memo. ERL<br />

ARL-224, NOAA Air Resources<br />

Laboratory, Silver Spring, MD, 24 pp.<br />

| | Draxler, R.R., Stunder, B., Rolph, G., and<br />

Stein, A., Taylor, A., Hysplit4 Users<br />

Guide, 2012.<br />

| | Eckerman, K., F., Ryman, J., C., Federal<br />

Guidance Report No. 12 External<br />

Exposure to Radionuclides in Air, Water<br />

and Soil, 1993.<br />

| | Environmental Modelling for Radiation<br />

Safety (EMRAS) Programme, The<br />

Chernobyl I-131 Release: Model<br />

Validation and Assessment of the<br />

Countermeasure Effectiveness: Report<br />

of the Chernobyl 131-I Release Working<br />

Group of EMRAS Theme 1.<br />

| | EUR-18825, FZKA-6311, ISBN 92-894-<br />

2085-5, European Communities 2001<br />

Probabilistic Accident Consequence<br />

Uncertainty Assessment Using COSYMA:<br />

Uncertainty from the Dose Module.<br />

| | EUR-18826, FZKA-6312, ISBN- 92-894-<br />

2088-X, European Communities 2001<br />

Probabilistic Accident Consequence<br />

Uncertainty Assessment Using COSYMA:<br />

Overall Uncertainty Analysis.<br />

| | Eyüpoğlu, F., Türkiye topraklarının<br />

verimlilik durumları, 1999.<br />

| | Gardner, R.H.: Huff, D.D., O'Neill, R.V.,<br />

Mankin, J.B., Carney, J. and Jones, J.:<br />

1980, Application of Error Analysis to a<br />

Marsh Hydrology Model, Water<br />

Resources Res. 16, 659-664.<br />

| | Gardner, R.H., O'Neill, R.V., Mankin, J.B.<br />

and Carney, J.H.: 1981, A Comparison<br />

of Sensitivity Analysis and Error Analysis<br />

Based on a Stream Ecosystem Model,<br />

Ecol. Modelling. 12, 173- 190.<br />

| | Garger, E.K., Hoffman, F.O., Thiessen,<br />

K.M., Uncertainty of the long-term<br />

resuspension factor, Atmos. Environ. 31<br />

(1997) 1647–1656.<br />

| | Health Canada, Recommendations on<br />

Dose Coefficients for Assessing Doses<br />

from Accidental Radionuclide Releases<br />

to the Environment, 1999.<br />

| | Health Protection Agency, Application<br />

of the 2007 Recommendations of the<br />

ICRP to the UK, 2009.<br />

| | Helton, J.C., Garner, J.W., Marietta,<br />

M.G., Rechard, R.E, Rudeen, D.K. and<br />

Swift, EN.: 1993. Uncertainty and<br />

Sensitivity Analysis Results Obtained in<br />

a Preliminary Performance assessment<br />

for the Waste Isolation Pilot Plant, Nuc.<br />

Sci. and Eng. 114, 286-331.<br />

| | Helton, J.C., Garner, J.W., McCurley, R.D.<br />

and Rudeen, D.K. Sensitivity analysis<br />

techniques and results for performance<br />

assessment at the waste isolation pilot<br />

plant. Albuquerque, NM: Sandia<br />

National Laboratory; Report No.<br />

SAND90-7103, 1991.<br />

Research and Innovation<br />

Design and Development of a Radio eco logical Domestic User Friendly Code for Calculation of Radiation Doses and Concentration due to Airborn Radio nuclides Release<br />

A. Haghighi Shad, D. Masti, M. Athari Allaf, K. Sepanloo, S.A.H. Feghhi and R. Khodadadi


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

Authors<br />

A. Haghighi Shad<br />

PhD in Nuclear Energy Eng<br />

Department of Nuclear Eng.<br />

Science and Research Branch<br />

of Islamic Azad University<br />

Tehran, Iran<br />

D. Masti<br />

Assistant of Prof. Azad University<br />

of Boushehr<br />

Boushehr NPP<br />

Manager of Research and<br />

Development in BNPP-1<br />

M. Athari Allaf<br />

Assistant of Prof.<br />

Department of Nuclear Eng.<br />

Science and Research Branch<br />

of Islamic Azad University<br />

Tehran, Iran<br />

K. Sepanloo<br />

Associate of Prof. Reactor and<br />

nuclear safety school<br />

Nuclear Science and Technology<br />

Research Institute (NSTRI)<br />

Tehran, Iran<br />

S.A.H. Feghhi<br />

Prof. Shahid Beheshti University<br />

of Tehran<br />

Department of Nuclear Eng.<br />

Deputy Manager of execution and<br />

Research in Nuclear Eng. Faculty<br />

Tehran, Iran<br />

R. Khodadadi<br />

Consultant<br />

Science and Research Branch<br />

of Islamic Azad University<br />

Tehran, Iran<br />

121<br />

EVENTS<br />

Event Report: Vertiefungskurs 2017:<br />

Zukunftsmanagement – zentrale<br />

Lösungsansätze für Kernanlagen<br />

Matthias Rey<br />

Zukunftsmanagement erfordert sorgfältige Planung und Wissen darüber, welche Optionen zur Verfügung<br />

stehen, wieweit Optimierungen sinnvoll sind und welche Maßnahmen und Prozessänderungen sich allenfalls bereits<br />

anderswo bewährt haben. Der Vertiefungskurs 2017 des Nuklearforums Schweiz nahm diese Thematik auf. Im Zentrum<br />

standen am ersten Kurstag Lösungsansätze zum Optimieren von Systembetrieb und Instandhaltung. Am zweiten Tag<br />

standen die Mitarbeitenden in seiner sich verändernden Umwelt im Fokus. Als Novum wurden dieses Jahr an beiden<br />

Nachmittagen die Themen der Inputreferate des Vormittags in Workshops vertieft diskutiert.<br />

Der neue Präsident der Kommission<br />

für Ausbildungsfragen des Nuklearforum<br />

Schweiz, Thomas Kohler,<br />

begrüßte die Teilnehmenden und<br />

wies auf das neue Format mit den<br />

Workshops hin, das aufgrund der<br />

Feedbacks zu vergangenen Kursen<br />

eingeführt worden ist.<br />

Optimierung von Systembetrieb<br />

und Instandhaltung<br />

In der Einleitung zum ersten Block<br />

wies Andreas Pfeiffer, Leiter des Kernkraftwerks<br />

Leibstadt, darauf hin, dass<br />

in der Schweiz bald das letzte KKW<br />

im deutschsprachigen Raum stehen<br />

dürfte. Die Betreiber stünden unter<br />

Druck seitens der Politik, müssten ihre<br />

Koten optimieren und sähen sich<br />

mit einer schrumpfenden Lieferantenbasis<br />

konfrontiert.<br />

Wie die ABB ihre Lieferanten<br />

bewirtschaftet legte Nikolaus Gäbler,<br />

Head of Supply Chain Management<br />

der Business Unit Grid Automation,<br />

dar. In der Schweiz gibt es ihm zufolge<br />

praktisch nur noch hoch spezialisierte<br />

Anbieter. Zudem sei die Supply<br />

Chain im Servicegeschäft besonders,<br />

charakterisiert durch ihre Kurzfristigkeit,<br />

wenig Beständigkeit und viele<br />

Sonderwünsche. Damit „die linke<br />

Hand genau weiss, was die rechte<br />

tut“, habe die ABB weltweit ein<br />

IT-Tool für das Lieferantenmanagement<br />

eingeführt, in das sämtliche<br />

Anfragen und Offerten eingetragen<br />

werden. Um langfristige Partnerschaften<br />

zu schaffen müsse man auch<br />

das Zwischenmenschliche berücksichtigen<br />

und sich manchmal mit<br />

Lieferanten treffen, ohne dass dabei<br />

gleich ein Geschäft entsteht. Um<br />

Kosten und Prozesse zu optimieren<br />

oder Abhängigkeiten zu reduzieren,<br />

kommt laut Gäbler vor, dass die ABB<br />

einen Lieferanten gleich komplett<br />

übernimmt.<br />

Im zweiten Referat zum Thema<br />

Reverse Engineering zeigte Florian<br />

Kanoffsky von der KSB AG auf, was ein<br />

Unternehmen tun kann, wenn seine<br />

Ersatzteile nicht mehr geliefert<br />

werden. Wenn sich kein anderer<br />

Lieferant findet und der Austausch der<br />

entsprechenden Komponenten keine<br />

Option ist, können Teile nachgebaut<br />

werden, was dann eben als «Reverse<br />

Engineering» bezeichnet wird.<br />

Kanoffsky beschrieb den typischen<br />

Ablauf solcher Aufträge von der<br />

Vermessung über das Erstellen von<br />

3D- und Guss-Modellen bis zur<br />

Endbear beitung. Bei der Planung<br />

müsse gerade in der Nuklearbranche<br />

den Genehmigungsprozessen, der<br />

Zeich nungsfreigabe sowie den Prüfungen<br />

und Abnahmen genug Zeit<br />

| | Vertiefungskurs 2017, wie gewohnt im Hotel Arte in Olten<br />

beige messen werden. Auch rechtliche<br />

Aspekte wie Patente und allenfalls<br />

Geheimhaltungsklauseln für Zeichnungen<br />

und Pläne in bestehenden<br />

Verträgen gelte es unbedingt zu<br />

beachten.<br />

Theoretische Ansätze,<br />

Fallstudien und Erfahrungsberichte<br />

Mit dem Referat von Giovanni<br />

Sansavini vom Reliability and Risk<br />

Engineering Laboratory der ETH Zürich<br />

zu Importance Measures ging es<br />

anschließend von der Praxis in die<br />

Theorie. Importance Measures quantifizieren<br />

die Bedeutung von Komponenten<br />

oder Ereignissen bei der<br />

Beurteilung der Systemperformance.<br />

Sie seien eine große praktische Hilfe<br />

für Systemdesigner und -manager,<br />

Events<br />

Event Report: Nuklearforum Schweiz – Future Management – Key Solutions for Nuclear Facilities ı Matthias Rey


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

122<br />

EVENTS<br />

da sie Schwachstellen im System<br />

aufzuspüren helfen und Richtlinien<br />

für die Verbesserung liefern.<br />

Danach ging es wieder in Richtung<br />

Praxis, genau gesagt zur Probabilistischen<br />

Sicherheitsanalyse (PSA)<br />

in KKW. Dusko Kancev, Fachverantwortlicher<br />

PSA Modellentwicklung<br />

und Sicherheitsindikatoren des Kernkraftwerks<br />

Gösgen, zeigte anhand<br />

einer PSA-Fallstudie, wie in KKW die<br />

Überwachungsanforderungen unter<br />

Berücksichtigung der Ausrüstungsalterung<br />

optimiert werden können.<br />

Mit dem verwendeten Modell kann<br />

die Alterung von Komponenten<br />

explizit, und nicht wie bei der<br />

„ traditionellen“ PSA stationär, dargestellt<br />

und letztendlich die Überwachungsintervalle<br />

der untersuchten<br />

Komponenten optimiert werden.<br />

Mit dem letzten Vortrag vor der Mittagspause<br />

folgte dann der erste, am<br />

Vertiefungskurs mittlerweile traditionelle<br />

Blick über den Tellerrand.<br />

Ronald Meier, Sektionsleiter Technische<br />

Organisation Zürich des Bundesamts für<br />

Zivilluftfahrt, stellte optimierte Instandhaltungsstrategien<br />

für den Langzeitbetrieb<br />

vor. Er ging auf Aspekte wie<br />

Ersatzteilstrategien und Lagerhaltung<br />

ein. Punkto Ersatzteile zahlen sich<br />

große Flotten des gleichen Flugzeugtyps<br />

sowie die Zusammenarbeit mit<br />

anderen Fluggesellschaften aus. Auch<br />

bei der Lagerhaltung spielt das sogenannte<br />

Pooling eine zunehmende<br />

Rolle, ebenso das Auslagern von<br />

Ersatzteillagern und die Tendenz zu<br />

zentralen größeren Lagern und nur<br />

kleinen Lagern vor Ort. Sowohl bei der<br />

Diversifizierung der Zulieferer als auch<br />

bei Reparaturen durch Eigenpersonal<br />

sind Überprüfungen und Zulassungen<br />

durch die Behörden nötig. Dass auch<br />

die Ausbildung streng reguliert ist und<br />

entsprechend lange dauert, führt zusammen<br />

mit eher kleinen Löhnen bei<br />

großer Verantwortung zu gewissen<br />

Nachwuchsproblemen in der Flugzeuginstandhaltung.<br />

Ein weiteres<br />

Problem stellen gefälschte oder nicht<br />

zugelassene Ersatzteile dar.<br />

Diskussion in Gruppen<br />

Am Nachmittag fand dann die besagte<br />

Premiere mit vier zeitgleich laufenden<br />

Workshops statt, für die sich die Teilnehmenden<br />

im Vorfeld angemeldet<br />

hatten. Eine Gruppe beschäftigte<br />

sich mit der Frage, was verlängerte<br />

Betriebszyklen für die Instandhaltung<br />

bedeuten. Lagerhaltung<br />

und Bestellkontrakte: vorbeugende<br />

Instandhaltung oder ‹run to<br />

failure›? lautete das Thema des<br />

zweiten Workshops. Die dritte Gruppe<br />

| | Diskussion im Workshop... | | ... und Präsentation im Plenum<br />

befasste sich mit der System Health<br />

und Systemzustandsberichten hinsichtlich<br />

des Kostenoptimierungspotenzials.<br />

Im vierten Workshop<br />

ging es um Möglichkeiten der Wertschöpfung<br />

und Belastungen der<br />

technischen Systeme, die der<br />

Lastfolge betrieb von KKW mit sich<br />

bringen kann. Der erste Kurstag<br />

endete mit der Präsentation der<br />

Resultate aus den einzelnen Workshops<br />

unter der Leitung von Michael<br />

Dost, Leiter des Kernkraftwerks<br />

Beznau, endete der erste Kurstag.<br />

Kompetenzanpassung<br />

und -transfer<br />

Den zweiten Tag des Vertiefungskurses<br />

eröffnete Martin Saxer, Leiter<br />

des Kernkraftwerks Mühleberg, mit<br />

dem Hinweis auf die Bedeutung der<br />

Menschen und ihrer Kompetenzen<br />

für das Zukunftsmanagement. Das<br />

erste Referat von Frank Sommer,<br />

Senior Vice President, Center of Competence<br />

Operations der PreussenElektra<br />

GmbH, erläuterter die Herausforderungen<br />

und Erfahrungen bei<br />

organisatorischen Veränderungen.<br />

Sommer erläuterte, wie der Energiekonzern<br />

E.ON entstanden ist und wie<br />

daraus letztlich die PreussenElektra<br />

hervorging. Er beleuchtete die Auswirkungen<br />

großer organisatorischer<br />

Veränderungen und Neuausrichtungen<br />

auf die Mitarbeitenden. In<br />

der Vergangenheit habe die große<br />

Herausforderung in der Integration<br />

von Kraftwerken etablierter Unternehmen<br />

aus verschiedenen Ländern<br />

in ein Großunternehmen bestanden.<br />

Dagegen stehe heute der Erhalt der<br />

Kompetenz für den sicheren Betrieb<br />

der Anlagen bis zur Stilllegung im<br />

Fokus. Um Sicherheit für die Mitarbeitenden<br />

zu erreichen und einen<br />

wirtschaftlichen Rückbau sicherzustellen<br />

sei es enorm wichtig, Nachbetrieb<br />

und Rückbau frühzeitig zu<br />

planen. Die Entwicklung eines internationalen<br />

Geschäfts schaffe in<br />

diesem Zusammenhang Perspektiven<br />

für die Belegschaften.<br />

Der darauf folgende Vortrag von<br />

Christer Johansson, Deputy Director<br />

Maintenance der Forsmarkskraftgrupp<br />

AB bei Vattenfall, stand unter ganz<br />

anderen Vorzeichen, da er von Strategien<br />

zur Laufzeitverlängerung<br />

handelte. Neben Strategien bei der<br />

Instandhaltung ging Jonansson vertieft<br />

auf den Kompetenzerhalt beim<br />

Personal ein. In Forsmark wird zum<br />

Beispiel wo immer möglich jüngeres<br />

Personal mit weniger Erfahrung<br />

zusammen mit langjährigeren Mitarbeitenden<br />

eingesetzt, oft auch unter<br />

Miteinbezug von Lieferanten. Darüber<br />

hinaus sei das Vorhandensein von<br />

Designregeln, Komponentenspezifikationen,<br />

Testergebnissen und weiterer<br />

Dokumentationen sowie das Wissen,<br />

wie die Komponenten im System<br />

funktionieren, Grundvoraussetzung<br />

für den Kompetenzerhalt.<br />

Know-how-Management und<br />

Know-why-Management in der<br />

Nuklearindustrie lautete der Titel<br />

des Beitrags von Tomas Hahn, Vice<br />

President Products and Projects der<br />

Areva GmbH. Die aktuelle wirtschaftliche<br />

Lage der europäischen<br />

Energieindustrie führt laut Hahn zu<br />

einem immer geringeren Volumen<br />

an Engineering- Aufgaben. Die neuen<br />

Schwerpunkte lägen beim Lebensdauer<br />

management und Modernisierungen,<br />

der Erhöhung von Sicherheitsstandards<br />

sowie der Weiterentwicklung<br />

des Stands von Wissenschaft<br />

und Technik. Die langen Laufzeiten<br />

von Kernkraftwerken bedingen den<br />

Transfer von Know-how von einer<br />

Generation von Ingenieuren zur<br />

nächsten. Daneben sei auch das Knowwhy-Training<br />

von großer Bedeutung,<br />

also die Vermittlung von Basis hintergrund<br />

wissen wie bestimmte Anlagen-<br />

Designs, Sicherheitskonzepte mit den<br />

Forderungen nach Redun danzen,<br />

Standards etc. und nicht zuletzt die<br />

Interaktion zwischen den verschiedenen<br />

Reaktorsystemen. Damit seien<br />

die Voraussetzungen gegeben, um<br />

komplexe technische Fragestellungen<br />

in einem anspruchsvollen Genehmigungsumfeld<br />

unter schwierigen<br />

Markt bedingungen professionell zu<br />

bearbeiten und die Bedürfnisse der<br />

Kunden zu befrie digen.<br />

Events<br />

Event Report: Nuklearforum Schweiz – Future Management – Key Solutions for Nuclear Facilities ı Matthias Rey


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

Sinkende Verfügbarkeit<br />

und steigender Bedarf<br />

Auf die Bedeutung des Kompetenzmanagements<br />

für die Aufsicht angesichts<br />

der aktuellen Entwicklungen in<br />

der Kerntechnik ging anschließend<br />

Holger Knissel, Fachspezialist Mensch<br />

und Organisation beim Eidgenössischen<br />

Nuklearsicherheitsinspektorat<br />

(Ensi), ein. In der Nuklearindustrie<br />

stehe aktuell eine sinkende Kompetenzverfügbarkeit<br />

einem steigenden<br />

Bedarf gegenüber. Gründe für die<br />

sinkende Verfügbarkeit sind der<br />

Generationswechsel in den Betriebsorganisationen,<br />

die wegen der politischen<br />

Randbedingungen abnehmende<br />

Attraktivität die zu Rekrutierungsproblemen<br />

führt, sowie der<br />

Kostendruck aufgrund der wirtschaftlichen<br />

Lage. Auf der anderen Seite<br />

nehme der Kompetenzbedarf zu, weil<br />

das Spektrum an benötigten Kompetenzen<br />

aufgrund der technologischen<br />

Entwicklungen immer breiter wird,<br />

weil die Alterung der Anlagen neue<br />

Fragestellungen aufwirft und weil der<br />

Support der Zulieferer abnimmt.<br />

Daraus folgerte Knissel, dass eine<br />

Kompetenzlücke zu entstehen droht.<br />

Dem könne und müsse mit aktivem<br />

Kompetenzmanagement entgegengewirkt<br />

werden.<br />

Der nächste Beitrag stellte einen<br />

weiteren Ausflug in die Aviatik dar:<br />

Nutzbarmachen von Erfahrungen<br />

aus ‹near misses› von Stefan Oser,<br />

Leiter Technical Training der Swiss International<br />

Air Lines Ltd. Er ging unter<br />

anderem der Frage nach, wie ein<br />

gesundes und vernünftiges Maß an Anleitungen,<br />

Checklisten und sonstiger<br />

Dokumentation für Instandhaltungsund<br />

Reparaturarbeiten aussieht und<br />

wie man die Leute dazu bringt, Vorkommnisse<br />

und Ab weichungen zu<br />

melden. Anhand von Erlebnissen aus<br />

seiner persönlichen Karriere legte er<br />

dar, wie wichtig lebenslanges Lernen,<br />

insbesondere aus Fehlern, ist.<br />

Freiheit der Forschung<br />

gewährleistet<br />

Für das letzte Inputreferat des diesjährigen<br />

Vertiefungskurses zeigte<br />

Horst-Michael Prasser von der ETH<br />

Zürich auf, was für den langfristigen<br />

Kompetenzerhalt in der Schweiz<br />

nötig ist. Er betonte eingangs, dass<br />

das neue Energiegesetz keine Einschränkungen<br />

für die Nuklearforschung<br />

beinhalte und das die Freiheit<br />

der Forschung gewährleistet sei. Auch<br />

gebe es keine spezifischen Budgetkürzungen<br />

für die Nuklearforschung<br />

am Paul Scherrer Institut PSI und die<br />

Professuren an den eidgenössischen<br />

Hochschulen. Weiter brauche es<br />

Kompetenzerhalt und Kompetenzentwicklung<br />

bei Kerntechnikern, angehenden<br />

Kerntechnikern sowie auch<br />

Kernenergiegegnern, denn ein profunder<br />

Disput über Kerntechnik sei<br />

eine objektive Notwendigkeit unserer<br />

Zeit. Offene, proaktive Kommunikation<br />

auch zu Problemen sei unerlässlich,<br />

ebenso wie breit angelegte<br />

Forschung und Bildung.<br />

| | Horst-Michael Prasser :«Ein profunder<br />

Disput über Kerntechnik ist eine objektive<br />

Notwendigkeit unserer Zeit.»<br />

Am Nachmittag beschäftigten sich<br />

drei Workshop-Gruppen unter der<br />

Leitung von Vertretern der Kernkraftwerke<br />

Gösgen, Mühleberg und<br />

Leibstadt mit der Frage nach dem<br />

richtigen Maß beim Erkennen und<br />

Melden von Befunden. Der vierte<br />

Workshop thematisierte den Kulturwandel<br />

und den Umgang mit Multinationalität<br />

in Kernkraftwerken. Die<br />

Ergebnisse wurden ebenfalls wieder<br />

im Plenum präsentiert und diskutiert,<br />

dieses Mal moderiert von Herbert<br />

Meinecke, dem Leiter des Kernkraftwerks<br />

Gösgen. Der Geschäftsführer<br />

des Nuklearforums, Beat Bechtold, verabschiedete<br />

anschließend die Teilnehmenden<br />

des Vertiefungskurses<br />

mit dem Hinweis, dass dieser von nun<br />

an voraussichtlich im Zweijahres-<br />

Rhythmus stattfindet.<br />

Author<br />

Matthias Rey<br />

Nuklearforum Schweiz /<br />

Forum nucléaire suisse<br />

Frohburgstrasse 20<br />

4600 Olten, Switzerland<br />

123<br />

KTG INSIDE<br />

Inside<br />

KTG: Wichtige Terminhinweise<br />

in eigener Sache<br />

Ankündigungen zum Vortag unserer diesjährigen Jahrestagung,<br />

dem 49 th Annual Meeting on Nuclear Technology<br />

(AMNT <strong>2018</strong>) vom 29. bis 30. Mai <strong>2018</strong> im Estrel-Hotel,<br />

Berlin:<br />

33<br />

KTG-Mitgliederversammlung<br />

• Wann? Montag, 28. Mai <strong>2018</strong>, 16.00 Uhr<br />

• Wo? Estrel Convention Center, Raum IV<br />

(2. OG), Sonnenallee 225, 12057 Berlin<br />

33<br />

Verleihung des Karl-Wirtz-Preises<br />

• Wann? Montag, 28. Mai <strong>2018</strong>, 18.00 Uhr<br />

• Wo? Estrel Convention Center, Raum IV<br />

(2. OG), Sonnenallee 225, 12057 Berlin<br />

33<br />

Get-together der KTG (auch für Nicht-Mitglieder)<br />

• Wann? Montag, 28. Mai <strong>2018</strong>, 19.00 Uhr<br />

• Wo? Estrel Convention Center, Leaf,<br />

Sonnenallee 225, 12057 Berlin<br />

KTG Fachgruppe Thermo- und<br />

Fluiddynamik<br />

Die KTG Fachgruppe Thermo- und Fluiddynamik<br />

beschäftigt sich mit<br />

• der Entwicklung, Validierung und Anwendung von<br />

Methoden und Computerprogrammen zur Berechnung<br />

von Strömungsvorgängen im Reaktorkühlkreislauf<br />

(RKL) sowie dem Containment,<br />

• der zur Validierung der Rechenmethoden erforderlichen<br />

Experimente einschließlich der Entwicklung von<br />

Messtechniken sowie<br />

• der Bestimmung von analytischen sowie experimentellen<br />

Unsicherheiten.<br />

Methoden, Computerprogramme und Experimente werden<br />

u.a. in kerntechnischen Verfahren genutzt, um Nachweise<br />

zu führen (Hersteller und Betreiber) oder unabhängig zu<br />

prüfen (Behörden und Gutachter) und die Einhaltung<br />

von Anforderungen aus dem kerntechnischen Regelwerk<br />

aufzuzeigen. Aktuelle Themen, die derzeit im Fokus der<br />

Fachgruppe stehen, sind die Weiterentwicklung und Validierung<br />

von eindimensionalen Systemcodes zur Simulation<br />

KTG Inside


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

124<br />

KTG INSIDE<br />

von innovativen Reaktorkonzepten mit passiven Sicherheitsmerkmalen,<br />

die Ertüchtigung von Computational Fluid<br />

Dynamic (CFD) Methoden zur Berechnung mehrphasiger<br />

Strömungszustände, die Entwicklung von Methoden zur<br />

Durchführung von Sensitivitäts- und Unsicherheitsanalysen<br />

für CFD Analysen. Des Weiteren werden aktuelle Fragestellungen<br />

zur technisch-wissenschaftlichen Absicherung<br />

des ver bleibenden Betriebs deutscher Kernkraftwerke und<br />

Forschungsreaktoren in der Fachgruppe aufgegriffen.<br />

Hierzu zählen u.a. Themen wie die mögliche Beeinträchtigung<br />

der Kernkühlung durch Isoliermaterial und oder<br />

Zinkboraten oder das sog. Neutronenflussrauschen.<br />

Der Vorstand der Fachgruppe, die derzeit um die 200<br />

Mitglieder besitzt, besteht derzeit aus 5 Personen. Dies sind<br />

Dr.-Ing. Andreas Schaffrath (Gesellschaft für Anlagen- und<br />

Reaktorsicherheit) gGmbH, der aktuell der Sprecher der<br />

Fachgruppe ist, Dipl.-Ing. Sören Alt (Hochschule Zittau,<br />

Görlitz), Dr.-Ing. Ingo Ganzmann (AREVA GmbH) und Prof.<br />

Dr.-Ing. Eckhart Laurien (IKE Stuttgart). Kassenwart und<br />

Kommunikationsbeauftragter der Fachgruppe ist Dr.-Ing.<br />

Jürgen Sydow (TÜV NORD Systems GmbH). Die Fach gruppe<br />

arbeitet – sofern dies thematisch erforderlich ist – interdisziplinär<br />

mit anderen Fachgruppen der KTG zusammen und<br />

organisiert z.B. gemeinsame Fach sitzungen auf dem jährlich<br />

stattfindendem Annual Meeting on Nuclear Technology<br />

(AMNT), KTG Fachtage oder Vortragsveranstaltungen. Die<br />

KTG Fachgruppe Thermo- und Fluiddynamik aktualisiert<br />

kontinuierlich ihren Internetauftritt.<br />

Die letzte große Veranstaltung der Fachgruppe war der<br />

Ende 2016 in Karlsruhe zusammen mit den Fachgruppen<br />

Reaktorphysik und Berechnungsmethoden und Reaktorsicherheit<br />

durchgeführte, 2-tägige Fachtag zu Aktuellen<br />

Themen der Reaktorsicherheit. Thematische Schwerpunkte<br />

des Fachtages waren neue Erkenntnisse aus den Bereichen<br />

Neutronenphysik, Anlagenbetrieb, BE-Lagerbecken, sowie<br />

Sensitivität, Entwicklung und Validierung von Codes<br />

sowie Tools zur Berechnung von Unsicherheiten und<br />

Sensitivitäten. Abgerundet wurde der Fachtag durch einen<br />

geselligen Abend. Der Fachtag war mit über 60 Teilnehmern<br />

gut besucht. Über den Fachtag wurde in der <strong>atw</strong><br />

(International Journal for Nuclear Power, Heft 10, 2016)<br />

sowie der Kerntechnik (Heft 5, 2016) berichtet. Darüber<br />

hinaus wurden diverse Beiträge des Fachtages im Heft 3,<br />

2017 der Kerntechnik veröffentlicht.<br />

Aktuell engagieren sich zahlreiche Mitglieder substantiell<br />

an der Vorbereitung des AMNT <strong>2018</strong>. Sie sind u.a. im<br />

Programmausschuss oder verschiedenen Auswahlausschüssen<br />

vertreten. Die Fachgruppe hat u.a. die Fokussitzung<br />

Safety of Advanced Nuclear Power Plants vor bereitet,<br />

in der zunächst ausgewählte Experten über aktuelle kerntechnische<br />

Entwicklungen in UK und China berichten. Es<br />

folgt dann ein Vortrag über eine Initiative der OECD/NEA<br />

zur Untersuchung und Bewertung thermohydraulischer<br />

Aspekte sog. passiver Sicherheitssysteme. Im Anschluss<br />

wird dann ein Vertreter des Bundesministeriums für<br />

Wirtschaft und Energie (BMWi) eine Übersicht über die<br />

derzeit in Deutschland durchgeführten Arbeiten im Bereich<br />

der Reaktorsicherheitsforschung geben. Es folgen abschließend<br />

zwei Vorträge, in denen herausragende BMWi<br />

finanzierte Forschungsarbeiten zu experimentellen und<br />

analytischen Untersuchungen passiver Systeme zur Beherrschung<br />

von Auslegungsstörfällen vorgestellt werden.<br />

Zusätzlich wurden bereits für die technischen Sitzungen<br />

des Key Topic Outstanding Know-How & Suitainable<br />

Innovations die eingereichten Abstracts gereviewt.<br />

Für das Jahr <strong>2018</strong> ist bereits – neben den üblichen<br />

Aktivitäten zur Vorbereitung des AMNT 2019 – zusammen<br />

mit der Sektion Süd eine Vortragsveranstaltung bei der<br />

Gesellschaft für Anlagen- und Reaktorsicherheit (GRS)<br />

gGmbH zu dem Thema Erweiterung der GRS Rechenkette<br />

für fortschrittliche Reaktoren geplant.<br />

Zu allen zuvor genannten Aktivitäten hoffen wir auf<br />

eine rege Teilnahme.<br />

Dr.-Ing. Andreas Schaffrath<br />

Sprecher der KTG Fachgruppe Thermo- und Fluiddynamik<br />

Kernfusion: Eine kleine Fachgruppe<br />

für ein Thema mit viel Zukunft<br />

Die Fachgruppe Kernfusion der KTG wurde erst 1997<br />

gegründet, also zu einer Zeit, als die KTG bereits 28 Jahre<br />

alt war. Derzeit hat sie 60 Mitglieder. Ihre thematischen<br />

Schwerpunkte liegen auf Fusionstechnologie und Plasmaphysik.<br />

Der Gründer und erste Sprecher der Fachgruppe war Dr.<br />

Gert Spannagel (FZK). Der Staffelstab wurde 20<strong>02</strong> weitergegeben<br />

an Michael Gehring (Babcock Noell), der ihn über<br />

10 Jahre lang hochhielt. Ich selbst erhielt ihn dann 2013.<br />

Obwohl die Fachgruppe Kernfusion in der KTG von<br />

Anfang an eine etwas kleinere Fachgruppe war, hat sie<br />

doch immer wieder durch ihre Aktionen und ihre Präsenz<br />

auf der Jahrestagung munter zum Leben und Programm<br />

der KTG beigetragen. In vielen Technischen und Fach-<br />

Sitzungen auf den Jahrestagungen verfolgte und kommunizierte<br />

sie die Weiterentwicklung der Kernfusionstechnologie<br />

und machte von Anfang an klar, dass Kerntechnik<br />

eben mehr ist als die technische Beherrschung der Kernspaltung.<br />

Zu den Highlights der Vergangenheit gehörte<br />

sicherlich auf der JK 2007 der Plenarvortrag von Kaname<br />

Ikeda, damals erster „Director-General“ des ITER-Projekts.<br />

Auch in jüngerer Vergangenheit wurden interessante<br />

Aktivitäten entwickelt. So konnten wir 2016 Prof. Robert<br />

Wolf für einen Plenarvortrag auf der AMNT zum Thema<br />

Wendelstein 7-X gewinnen. Der W7X hatte erst wenige<br />

Monate zuvor sein erstes Plasma gesehen und gezeigt, dass<br />

er über ein nahezu perfektes Magnetfeld verfügt. Und<br />

2017 organisierten wir im Anschluss an die AMNT eine<br />

Exkursion nach Greifswald, um uns diesen W7X mal selbst<br />

anzusehen. Dass dabei Dr. Spannagel zu den Expeditionsteilnehmern<br />

gehörte, hat mich besonders gefreut. Vor Ort<br />

in Greifswald gab uns Prof. H.-S. Bosch einen umfassenden<br />

Einblick in die Besonderheiten des W7X, seine Inbetriebnahme,<br />

über die Ergebnisse der ersten Betriebsphase<br />

und die Pläne zum weiteren Projektverlauf. Anschließend<br />

erklärte uns Dr.-Ing. L. Wegener die Besonderheiten<br />

und Herausforderungen des W7X-Projekts hinsichtlich<br />

Konstruktion, Organisation und Projektmanagement. So<br />

waren wir schon vor der eigentlichen Führung beeindruckt<br />

und sensibilisiert für das, was wir anschließend auch aus<br />

der Nähe zu sehen bekamen.<br />

Neben den Aktionen und dem „Blick über den Tellerrand“<br />

der Kernspaltungstechnik, den wir bieten, stellt<br />

unsere Fachgruppe aber auch einen Link dar zu anderen<br />

Fusions-orientierten Körperschaften wie den deutschen<br />

Fusionslaboren (IPP, KIT und FZJ), dem deutschen ITER<br />

Industrie Forum (dIIF), dem Europäischen Fusion Industry<br />

Innovation Forum (FIIF) und anderen.<br />

Und was wir in der Zukunft vorhaben? Schließen Sie<br />

sich unserer Fachgruppe an und wünschen Sie sich etwas!<br />

Dr. Thomas Mull<br />

Sprecher der KTG Fachgruppe Kernfusion<br />

KTG Inside


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

KTG-Sektion Ost:<br />

Exkursion<br />

Die KTG-Exkursion 2017 der Sektion Ost führte uns in das<br />

mitteldeutsche Braunkohlegebiet zur MIBRAG südlich von<br />

Leipzig. Die erste Station war das Braunkohlekraftwerk<br />

Deuben mit der angeschossenen Brikettfabrik. Das Kraftwerk<br />

stammt aus den 1930er Jahren. Der erste Eindruck<br />

des Kraftwerkskomplexes überraschte uns mit der gelungenen<br />

Architektur der erhaltenen Industrie gebäude in Ziegelbauweise.<br />

Nach dem Besuch des Leitstandes konnten<br />

wir im Kraftwerksgebäude in einen stillgelegten Braunkohle-Feuerungskessel<br />

einsteigen und erhielten anschaulich<br />

einen Einblick in die Funktionsweise und die technischen<br />

Herausforderungen des Kraftwerks. Beim anschließenden<br />

Rundgang durch den Generatorsaal erfuhren wir,<br />

dass ein Großteil der erzeugten Energie für die Großgeräte<br />

des angeschlossenen Tagebaus und für den Transport der<br />

Braunkohle mit Förderbändern und E-Loks benötigt wird.<br />

Leider konnte die geplante Besichtigung der Brikettfabrik<br />

wegen eines Stillstandes nicht stattfinden.<br />

freigesetzten elementaren Quecksilbers führte zum<br />

Auftragseingang. Heute werden unter anderem quecksilberhaltige<br />

Schlämme und Rückstände mit natürlicher<br />

Radioaktivität behandelt. Diese Rückstände in Form<br />

von Schlämmen entstehen beispielsweise bei der Erdgasförderung.<br />

Die Schlämme werden thermisch behandelt<br />

und dabei Quecksilber gewonnen, das dann hochrein<br />

vermarktet wird. Die Rückstände mit natürlicher Radioaktivität<br />

werden immobilisiert und auf spezielle Deponien<br />

verbracht. Bei einem Rundgang durch die Produktionshallen<br />

wurden uns anschaulich die Technologien beim<br />

Metallrecycling erläutert.<br />

Mit vielen neuen Eindrücken, die auf uns in den zwei<br />

Tagen einwirkten, haben wir dann die Heimreise angetreten.<br />

Besonderer Dank geht an die Mitarbeiter der beiden<br />

Firmen für die intensive und offene Betreuung während<br />

der Führungen.<br />

B. Standfuß et al.<br />

Zwischen Forschung, Rückbau<br />

und Entsorgung – aktuelle Aufgaben<br />

in der Kerntechnik<br />

125<br />

KTG INSIDE<br />

| | KTG-Sektion Ost: Exkursion 2017<br />

Im Tagebau Profen konnten wir uns von der Besucherplattform<br />

aus einen Überblick über die Ausmaße des<br />

Tagebaus verschaffen. Am Nachmittag fuhren wir dann<br />

zum Tagebau Schleenhain. Nach dem Besuch der Kaue und<br />

des Leitstandes des Tagebaues fuhren wir im Besucherbus<br />

im Tagebau direkt bis an die Schaufelradbagger, die Eimerkettenbagger<br />

und die kilometerlangen Bandanlagen. Es<br />

wurde erläutert, dass die Sanierung der Tagebauflächen<br />

nach der Verfüllung noch sechs Jahre vom Tagebauunternehmen<br />

durchgeführt wird. Mehrere Anpflanzungen und<br />

Fruchtfolgen garantieren, dass danach das Gelände wieder<br />

mit hoher Ackerzahl landwirtschaftlich ertragreich<br />

genutzt werden kann. In Gesprächen mit MIBRAG-<br />

Mitarbeitern wurde von diesen die technikfeindliche<br />

Einstellung von zunehmenden Teilen der Gesellschaft<br />

bedauert, die bei der Einstellung des Braunkohlentagebaus<br />

allein in Mitteldeutschland mehrere zehntausend<br />

Arbeitsplätze kosten würde.<br />

Mit einem geselligen Abend und Diskussionen,<br />

beendeten wir den sehr informativen Tag.<br />

Am nächsten besuchten wir die Gesellschaft für<br />

Metallrecycling Leipzig (GMR) in der Produktionsstätte<br />

Espenhain. Während eines informativen Einführungsvortrages<br />

erhielten wir einen Einblick in die Tätigkeitsfelder<br />

der Firma. Der Ursprung der Firma stammt aus einem<br />

Auftrag zur schadlosen Vernichtung von Munition für<br />

Sturmgewehre der ehemaligen NVA; insbesondere die<br />

Alleinstellung in der BRD mit der Fähigkeit zur Rückhaltung<br />

des bei der Verbrennung von Knallquecksilber<br />

Nachwuchstagung der Jungen Generation<br />

der KTG vom 8. – 10. November 2017<br />

Deutschland war über Jahrzehnte führend in der Entwicklung<br />

der Kerntechnik und dem sicheren und<br />

wirtschaft lichen Betrieb kerntechnischer Anlagen. Seit<br />

dem im Jahr 2011 beschlossenen beschleunigten Ausstieg<br />

aus der Kernenergienutzung ist die Hälfte der Zeit vergangen,<br />

bis das letzte deutsche Kernkraftwerk vom Netz<br />

genommen werden soll.<br />

Knapp 50 Teilnehmer waren der Einladung der Jungen<br />

Generation der KTG zur Nachwuchstagung nach Karlsruhe<br />

gefolgt. Der Campus Nord des Karlsruher Institut<br />

für Technologie (KIT), das frühere Forschungszentrum<br />

Karlsruhe, war seit den 1950er Jahren eine der Hauptstützen<br />

der kerntechnischen Entwicklung Deutschlands.<br />

Viele kerntechnische Forschungsrichtungen mit ihren<br />

Versuchs-, Pilot- und Forschungsanlagen, aber auch Einrichtungen<br />

der kerntechnischen Industrie waren hier<br />

beheimatet, einige sind es bis heute. Wie im restlichen<br />

Land stehen auch hier die Zeichen auf Rückbau – zum<br />

einen, weil einige Anlagen unterdessen das Ende ihrer<br />

Nutzungszeit erreicht haben, zum anderen aber auch,<br />

weil Rückbau, Entsorgung und Endlagerung wichtige<br />

Forschungsthemen sind.<br />

Als Teil der „Energiewende“ wird der anstehende<br />

Rückbau der Kernkraftwerke immer konkreter – Grund<br />

genug, sich direkt bei einem Elektroenergieerzeuger zu<br />

informieren, wie die Unternehmen damit umgehen. Die<br />

Teilnehmer konnten der Einladung in die EnBW-Zentrale in<br />

Karlsruhe folgen, um dort bei einem Get-together in<br />

entspannter Atmosphäre eine kurze Ansprache des<br />

Geschäftsführers der EnBW Kernkraft GmbH, Herrn Jörg<br />

Michels, zu hören. Seinen Worten zufolge hat EnBW den<br />

Rückbau auch seiner noch im Leistungsbetrieb befind lichen<br />

KKW zeitlich und monetär auskömmlich geplant. Er ermunterte<br />

die Teilnehmer ausdrücklich, optimistisch in die<br />

Zukunft zu sehen! Dieser Optimismus fußt auf mehreren<br />

Gründen: Der Rückbau der KKW wird nicht innerhalb einer<br />

Dekade abgeschlossen sein. Weiterhin erwirbt man in<br />

einem Rückbauprojekt Kompetenzen, die sich mühelos auf<br />

KTG Inside


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

126<br />

KTG INSIDE<br />

| | KONRAD-Container am Haken –<br />

Umlagerung im Zwischenlager<br />

der KTE auf dem Campus Nord<br />

| | Der Master-Slave-Manipulator –<br />

was so leicht aussieht, ist dann<br />

doch recht schwer...<br />

Projekte abseits der Kernenergie erzeugung anwenden<br />

lassen – das Lösen ingenieur technischer<br />

Anforderungen sowie enge Termin- und Kostenkontrolle<br />

erfordern alle Projekte, ob innerhalb<br />

oder außerhalb kerntechnischer Anwendungen!<br />

Schlussendlich erhält man innerhalb eines<br />

Rückbau projekts, welches verschiedenste Gewerke<br />

und Industriezweige<br />

mit- und nebeneinander tätig werden lässt,<br />

einen hohen Grad an Vernetzung mit verschiedenen<br />

Branchen.<br />

Der folgende Tag begann früh. Der Bus<br />

brachte die Teilnehmer vom Tagungshotel zum<br />

KIT Campus Nord. Nach einer Vorstellung des<br />

KIT, erfuhren wir, an welchen Stellen der<br />

Rückbau hinsichtlich eingesetzter Technik<br />

nicht nur Handwerk ist, sondern durchaus<br />

auch Aufgaben für die ingenieurtechnische<br />

Wissenschaft bereithält. Nach der Vorstellung<br />

der aktuellen und früheren Aufgaben des Instituts<br />

für Nukleare Entsorgung (INE), wo im<br />

Rahmen gesellschaftlicher Vorsorgeforschung<br />

grundlegende und anwendungsorientierte<br />

FuE-Arbeiten zur sicheren Ent sorgung radioaktiver<br />

Abfälle durchgeführt sowie Fragestellungen<br />

zum Rückbau kerntechnischer Anlagen<br />

thematisiert werden, starteten Besichtigungen.<br />

Im INE-Kontrollbereich wurden Details zu<br />

endlagerungsvorbereitenden Untersuchungen<br />

an Brenn elementen, zur Aktiniden forschung und über<br />

Möglichkeiten der Laserspek troskopie vorgestellt.<br />

An den INE-Beamlines der Synchrotron Radiation<br />

Facility „KARA“ erfuhren wir Details zu den Möglichkeiten<br />

und Anwendungsgebieten der Bildgebung mittels<br />

Röntgenstrahlung.<br />

Der Nachmittag gehörte ausführlichen Besichtigungen<br />

an den Anlagen der Kerntechnische Entsorgung Karlsruhe<br />

GmbH (KTE) am KIT Campus Nord – Zwischenlager, Wiederaufarbeitungsanlage<br />

(WAK) und Mehrzweckforschungsreaktor<br />

(MZFR).<br />

Das Zwischenlager beeindruckte durch seine Dimensionen.<br />

Interessant zu sehen, mit welchen Untersuchungsmethoden<br />

Reststoffe nach Eingang kontrolliert und<br />

qualifiziert werden. Die angewendeten Verfahren kommen<br />

auch bei der Nachqualifizierung älterer Reststoffe zum<br />

Einsatz. Parallel wird ein hoher Aufwand bei der Pflege der<br />

älteren Gebinde und der Konditionierung von Gebinden<br />

für das Endlager KONRAD betrieben.<br />

In der WAK erhielten wir Einblick in die Vorbereitungen<br />

des fernhantierten Rückbaus der Bereiche, die für einen<br />

manuellen Rückbau nicht zugänglich sind. Die Ortsdosisleistung<br />

ist insbesondere in der Verglasungsanlage so hoch, dass<br />

auch technische Geräte nach begrenzter Einsatzdauer beeinträchtigt<br />

werden bzw. versagen. Teils müssen hier zur<br />

Steuerung der Rückbauwerkzeuge Techniken und Verfahren<br />

etabliert werden, die in der Form bisher noch nirgends<br />

zum Einsatz kamen.<br />

Am MZFR konnten wir ein Kernkraftwerk in seinen<br />

„späten Jahren“ erleben. Die Führung brachte uns zu<br />

vielen interessanten Orten innerhalb dieses im Wesentlichen<br />

bis auf die Ge bäudestruktur entkernten Gebäudes.<br />

Neben letzten Rückbauarbeiten ist man dort mit dem<br />

messtech nischen Nachweis der Freigabefähigkeit, die zur<br />

Freigabe des Gebäudes gemäß § 29 StrlSchV führen soll,<br />

befasst. Interessant, wie anspruchsvoll auch oder gerade<br />

solche letzten Schritte sind, wo nicht mehr der Schutz der<br />

Person vor der Direktstrahlung, sondern der Nachweis der<br />

Kontaminations freiheit im Vordergrund steht.<br />

Der Tag wurde mit einem gemütlichen Beisammensein<br />

bei Speis und Trank abge rundet. Dabei waren Zeit und<br />

Gelegenheit, neue Kontakte zu knüpfen oder bestehende<br />

Kontakte zu vertiefen.<br />

Auch der letzte Tagungstag begann früh. Nach den<br />

intensiven Eindrücken des Vortags zu Rückbau und<br />

nuklearer Reststoffwirtschaft stand nun der wirtschaftliche<br />

und politische Rahmen des Rückbaus im Fokus.<br />

Zuerst wurde die Rolle der EU hinsichtlich wissenschaftlicher<br />

und politischer Unterstützung thematisiert.<br />

Zwei weitere Vorträge zeigten an praktischen<br />

Beispielen, was in Kernkraftwerken nach der Abschaltung<br />

passiert. Anhand der Kernkraftwerke Philippsburg und<br />

Neckarwestheim wurde gezeigt, wie das Management von<br />

Reststoffen vom Rückbau über den Transport bis hin zur<br />

Rezyklierung ineinandergreift – einfach gesagt: „Was<br />

passiert mit einem Kernkraftwerk nach der Abschaltung?“.<br />

Im Folgenden wurde berichtet, wie in den Blöcken A<br />

und B des Kernkraftwerks Biblis in Umsetzung erteilter<br />

Stilllegungs- und Rückbaugenehmigungen erste Abbaumaßnahmen<br />

durchgeführt werden. Geplant ist hier, auch<br />

im Unterschied zu den Anlagen in Philippsburg und<br />

Neckarwestheim, die Abbau- und Reststoffbearbeitungstätigkeiten<br />

innerhalb der bestehenden Gebäude durchzuführen.<br />

| | Tagungsteilnehmer auf Besichtigungstour am Institut für Technische Physik<br />

Im Anschluss wurde die Kostenschätzung von Stilllegungs-<br />

und Rückbaumaßnahmen thematisiert. Wichtig<br />

dabei ist, dass die Gesamtkosten mindestens zutreffend,<br />

jedoch keinesfalls zu niedrig geschätzt werden. Diese Verpflichtung<br />

ergibt sich nicht zuletzt aus den Bestimmungen<br />

zur Entsorgung von Kernkraftwerken bzw. -anlagen.<br />

Zugleich sind steuerrechtliche Vorgaben zu beachten, da<br />

Rückstellungen den steuerpflichtigen Gewinn mindern.<br />

Nicht zuletzt vor dem Hintergrund steigender Preise und<br />

teils unsicherer gesetzlicher Rahmenbedingungen haben<br />

die Betreiber ein vitales Interesse, dass die Gesamtkosten<br />

des Rückbaus ausreichend abgeschätzt werden.<br />

Den Abschluss des Vortragsteils am Vormittag bildeten<br />

Einblicke in die automatisierte Zerlegung von RDB-<br />

Einbauten mittels Unterwasser-Robotertechnik. Von der<br />

Ertüchtigung des Basisgeräts zur Unterwasserfähigkeit<br />

über die Erarbeitung eines Interventionskonzepts, der Entwicklung<br />

eines „Masterarms“ für die Werkzeugaufnahme,<br />

der Entwicklung eines Werkzeugwechselsystems bis zur<br />

Ausarbeitung von Schutzmechanismen ist dabei ein breites<br />

Spektrum von Herausforderungen zu bestehen, bevor der<br />

erste Einsatz stattfinden kann.<br />

KTG Inside


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

Gestärkt vom Mittagessen wurde die Tagung am<br />

Nachmittag mit der Besichtigung der Spultestanlage<br />

TOSKA des Instituts für Technische Physik (ITEP) am KIT,<br />

einer Anlage, in der große supraleitende Magnete für die<br />

Fusion getestet werden, sehr erfolgreich beendet.<br />

Dank an dieser Stelle allen Vortragenden und Organisatoren<br />

des KIT und KTE für die sehr guten Führungen und<br />

die perfekte Organisation des Besichtigungsnachmittags<br />

als auch allen weiteren Vortragenden aus der Industrie!<br />

Unser Dank gilt weiterhin allen Organisatoren, die<br />

erhebliche Teile ihrer Freizeit für das Zustandekommen<br />

und die Ausgestaltung der Tagung geopfert haben. Weiterhin<br />

danken wir unseren Arbeitgebern, Helfern sowie<br />

direkten und indirekten Sponsoren und Unterstützern.<br />

Ohne ihr Wirken hätte die Tagung nicht zu einem Erfolg<br />

werden können.<br />

Sven Jansen<br />

Im Namen des Vorstands der Jungen Generation der KTG<br />

MINT pink: WiN dabei<br />

Am 20.11.2017 fand im Körber-Forum in Hamburg der<br />

Programmabschluss von „MINT pink“ statt. MINT pink ist<br />

ein schulübergreifendes Programm, das ausgewählte<br />

Schülerinnen der Mittelstufe für die Wahl eines naturwissenschaftlichen<br />

Profils in der Oberstufe ermutigt<br />

und Studien-, Arbeits- und Karrieremöglichkeiten<br />

im Mathe matik- Informatik-Naturwissenschaft-Technik-<br />

Bereich auf zeigt.<br />

| | MINT pink: WiN dabei. Chantal Greul stellt ihren Beruf in der Kerntechnik<br />

Schülerinnen vor.<br />

Chantal Greul durfte als Role Model über 90 Mädchen<br />

den Beruf der Ingenieurin in der Kerntechnik vorstellen.<br />

Nach einer kurzen Vorstellung des eigenen Lebenslaufes<br />

und des Arbeitsalltages in einer kerntechnischen Anlage,<br />

durften die Schülerinnen in kleinen Gesprächsrunden<br />

ihre Fragen stellen. Diese reichten von allgemeinen Fragen<br />

bis hin zu spezifischen Fachfragen rund um Kernenergie,<br />

Rückbau und Endlagerung in Deutschland. Die Veranstaltung<br />

war eine interessante Gelegenheit mit potenziellem<br />

Nachwuchs in Kontakt zu kommen und sie über<br />

die spannende Arbeit in der Kernenergiebranche zu<br />

informieren. Auch die Programmauswertung zeigt den<br />

Erfolg des MINT-pink-Programmes. Vor Programmstart<br />

konnten sich 27 % der Mädchen vorstellen, das Physikoder<br />

Chemieprofil in der Oberstufe zu wählen. Nach<br />

Programmende waren es 45 %.<br />

KTG Inside<br />

Verantwortlich<br />

für den Inhalt:<br />

Die Autoren.<br />

Lektorat:<br />

Sibille Wingens,<br />

Kerntechnische<br />

Gesellschaft e. V.<br />

(KTG)<br />

Robert-Koch-Platz 4<br />

10115 Berlin<br />

T: +49 30 498555-50<br />

F: +49 30 498555-51<br />

E-Mail: s.wingens@<br />

ktg.org<br />

127<br />

KTG INSIDE<br />

Yvonne Broy<br />

www.ktg.org<br />

Advertisement<br />

KTG Inside


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

128<br />

KTG INSIDE<br />

Wenn Sie keine<br />

Erwähnung Ihres<br />

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teilen Sie dies bitte<br />

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Glückwunsch<br />

Februar <strong>2018</strong><br />

90 Jahre wird<br />

10. Dipl.-Ing. Hans-Peter Schabert,<br />

Erlangen<br />

89 Jahre wird<br />

20. Dr. Helmut Hübel, Bensberg<br />

88 Jahre wird<br />

5. Dr. Eberhard Teuchert, Leverkusen<br />

87 Jahre wird<br />

14. Dipl.-Ing. Heinrich Kahlow, Rheinsberg<br />

85 Jahre wird<br />

11. Dr. Rudolf Büchner, Dresden<br />

84 Jahre werden<br />

9. Dr. Horst Keese, Rodenbach<br />

12. Dipl.-Ing-. Horst Krause, Radebeul<br />

23. Prof. Dr. Dr.-Ing. E.h. Adolf Birkhofer,<br />

Grünwald<br />

82 Jahre werden<br />

6. Dr. Ashu-T. Bhattacharyya, Erkelenz<br />

17. Dr. Helfrid Lahr, Wedemark<br />

81 Jahre werden<br />

5. Prof. Dr. Arnulf Hübner, Berlin<br />

6. Dipl.-Ing. Heinrich Moers,<br />

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11. Dr. Günter Keil, Sankt Augustin<br />

18. Dipl.-Ing. Hans Wölfel, Heidelberg<br />

21. Dipl.-Ing. Hubert Andrae, Rösrath<br />

80 Jahre wird<br />

15. Dr. Hans-Heinrich Krug, Saarbrücken<br />

79 Jahre werden<br />

3. Dr. Roland Bieselt, Kürten<br />

8. Dr. Joachim Madel, St. Ingbert<br />

8. Dr. Herbert Spierling, Dietzenbach<br />

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78 Jahre werden<br />

9. Dr. Gerhard Preusche, Herzogenaurach<br />

13. Dr. Hans-Ulrich Fabian, Gehrden<br />

14. Dipl.-Ing. Kurt Ebbinghaus,<br />

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21. Dr. Jürgen Langeheine, Gauting<br />

23. Dr. Gerhard Heusener, Bruchsal<br />

25. Prof. Dr. Sigmar Wittig, Karlsruhe<br />

77 Jahre wird<br />

16. Dr. Jürgen Lockau, Erlangen<br />

76 Jahre werden<br />

6. Dr. Michael Schneeberger, Linz/A<br />

22. Cornelis Broeders, Linkenheim<br />

Die KTG gratuliert ihren Mitgliedern sehr herzlich zum<br />

Geburtstag und wünscht ihnen weiterhin alles Gute!<br />

75 Jahre werden<br />

5. Dr. Joachim Banck, Heusenstamm<br />

9. Dr. Friedrich-Karl Boese, Leonberg<br />

13. Dr. Ingo-Armin Brestrich, Plankstadt<br />

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28. Dr. Klaus Tägder, Sankt Augustin<br />

70 Jahre werden<br />

7. Dr. Hans-Hermann Remagen, Brühl<br />

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14. Reinhold Rothenbücher, Erlangen<br />

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29. Dr. Anton von Gunten, Oberdiessbach<br />

65 Jahre werden<br />

3. Dr. Reinhard Knappik, Dresen<br />

20. Dipl.-Ing. Berthold Racky, Nidderau<br />

60 Jahre werden<br />

3. Prof. Dr. Sabine Prys, Offenburg<br />

3. Dipl.-Ing. Siegfried Wegerer,<br />

Tiefenbach<br />

10. Dipl.-Ing. (FH) Anton Hums,<br />

Essenbach<br />

50 Jahre werden<br />

5. Dr. Volker Wunder, Ottensoos<br />

20. Dr. Josef Engering, Jülich<br />

22. Toralf Wolf, Plauen<br />

28. Dipl.-Ing. Jörg Schneider, Radebeul<br />

März <strong>2018</strong><br />

91 Jahre wird<br />

27. Prof. Dr. Bernhard Liebmann,<br />

Kronberg<br />

88 Jahre werden<br />

6. Prof. Dr. Hubertus Nickel, Jülich<br />

25. Dr. Hans-Ulrich Borgstedt, Karlsruhe<br />

25. Dr. Peter Borsch, Dresden<br />

87 Jahre wird<br />

17. Dipl.-Ing. Hans Waldmann<br />

86 Jahre wird<br />

14. Dr. Peter Engelmann,<br />

Eggenstein-Leopoldshafen<br />

85 Jahre werden<br />

26. Dipl.-Ing. Gerhard Frei, Uttenreuth<br />

30. Dipl.-Phys. Dieter Pleuger, Kiedrich<br />

84 Jahre werden<br />

1. Prof. Dr. Günther Kessler, Stutensee<br />

18. Dipl.-Ing. Willi Riebold, München<br />

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83 Jahre werden<br />

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14. Dr. Hermann Kraemer, Seevetal<br />

82 Jahre werden<br />

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8. Prof. Dr. Erich Tenckhoff, Erlangen<br />

19. Dr. Hermann Hinsch, Hannover<br />

81 Jahre wird<br />

29. Dipl.-Ing. Friedrich Garzarolli, Fürth<br />

80 Jahre werden<br />

4. Dr. Rainer Göhring, Nauen<br />

6. Dipl.-Math. Udo Harten, Stutensee<br />

10. Dr. Hein-Jürzen Kriks, Braunschweig<br />

11. Peter Vagt, Rösrath<br />

14. Dr. Peter Paetz, Bergisch Gladbach<br />

16. Prof. Dr. Helmut Röthmeyer,<br />

Braunschweig<br />

22. Dr. Bruno-J. Baumgartl, Weiterstadt<br />

79 Jahre werden<br />

1. Prof. Dr. Günter Höhlein, Wiesbaden<br />

1. Dipl.-Ing. Wolfgang Dietz, Lindlar<br />

7. Dr. Kurt Vinzens, Berg-Aufkirchen<br />

17. Dipl.-Phys. Renate von Le Suire,<br />

Seeshaupt<br />

2. Dipl.-Ing. Helmut Pekarek,<br />

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25. Dipl.-Ing. Joachim Koch, Mömbris<br />

78 Jahre werden<br />

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3. Dr. Lutz Niemann, Holzkirchen<br />

3. Dipl.-Ing. Eberhard Schomer, Erlangen<br />

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12. Prof. Dr. Arndt Falk, Sterup<br />

18. Dipl.-Ing. Friedhelm Hülsmann,<br />

Garbsen<br />

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29. Ing. Dieter-W. Sauer, Berlin<br />

29. Dipl.-Phys. Harald Reinhardt,<br />

Leverkusen<br />

77 Jahre werden<br />

4. Ing. Ulrich Ristow, Neu-Isenburg<br />

8. Dr. Frank Steinbrunn, Fröndenberg<br />

14. Dipl.-Ing. Bernd Jürgens, Hirschberg<br />

22. Dipl.-Phys. Gerhard Jourdan, Landau<br />

76 Jahre wird<br />

10. Dipl.-Phys. Alfons Scholz, Brühl<br />

75 Jahre werden<br />

7. Dr. Peter Royl, Stutensee<br />

16. Dipl.-Ing. Jochen Heinecke, Kürten<br />

20. Dipl.-Ing. Jörg Brauns, Hanau<br />

26. Dr. Jürgen P. Lempert, Hannover<br />

26. Graeme William Catto, Buch a. Erlbach<br />

70 Jahre werden<br />

5. Dipl.-Wirtsch.-Ing. Bernd Pontani,<br />

Alzenau<br />

13. Dipl.-Kfm. Jochen Bläsing, Mörlenbach<br />

22. Dr. Volker Mirschinka, Essen<br />

65 Jahre wird<br />

21. Dr. Ulrich Rohde, Dresden<br />

60 Jahre wird<br />

26. Dr. Sheikh Shahee, Leinburg<br />

50 Jahre werden<br />

20. Thomas Wiese, Ebermannstadt<br />

30. Dipl.-Ing. Heiko Ringel, Offingen<br />

KTG Inside


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

Top<br />

IAEA: Solving the back end:<br />

Finland’s key to the final<br />

disposal of spent nuclear fuel<br />

(iaea) Countries operating nuclear<br />

power plants store their spent nuclear<br />

fuel either at reactor sites or away<br />

from them. Spent fuel can be dangerous<br />

to people and the environment<br />

if not properly managed; therefore,<br />

a publicly acceptable, permanent<br />

solution for its disposal is needed.<br />

While a number of countries are<br />

considering deep geological disposal<br />

repositories, Finland is the only<br />

country that has begun the construction<br />

of a repository for the final<br />

disposal of its spent nuclear fuel.<br />

At a depth of 400 to 450 metres<br />

and with about 70 km of tunnels and<br />

shafts, the ONKALO repository in<br />

Olkiluoto on Finland’s west coast<br />

will house copper canisters filled<br />

with spent fuel from nuclear power<br />

reactors. It is expected to receive<br />

waste for about 100 years, after which<br />

time it will be sealed.<br />

“Since the decision was made<br />

40 years ago on the overall waste<br />

management strategy and on a deep<br />

geological repository as the primary<br />

option for spent nuclear fuel, all the<br />

stakeholders have stood by it,” said<br />

Tiina Jalonen, Senior Vice President<br />

for Development at Posiva, the company<br />

in charge of the project. “Governments<br />

and people have changed,<br />

but the decision and the vision for the<br />

future have remained the same.”<br />

Another reason why Finland’s<br />

model has worked is the timely<br />

involvement of all the stakeholders in<br />

the project, who worked as one team,<br />

targeting the same goal.<br />

“The roles between the different<br />

stakeholders have been clear. The<br />

decision makers have developed<br />

legislation in parallel to introducing<br />

nuclear energy, and the Radiation and<br />

Nuclear Safety Authority of Finland<br />

(STUK) has developed safety guides,<br />

regulations and competences to<br />

review and inspect our documentation<br />

and applications,” said Jalonen.<br />

Moreover, involving STUK from the<br />

beginning was crucial to building the<br />

trust in the project. “It wouldn’t have<br />

worked if any of the stakeholders were<br />

missing from the process,” explained<br />

Petteri Tiippana, Director General at<br />

STUK. “Active participation of the safety<br />

regulator provided the local community<br />

with additional assurances.”<br />

In fact, public acceptance was<br />

crucial for the success of the project.<br />

The selection of the Olkiluoto site<br />

–home to three nuclear reactors – as<br />

the repository site was made, not only<br />

for the geological suitability of this<br />

area, but also for the acceptance of the<br />

people living there. Finland conducted<br />

many studies about local and<br />

national attitudes toward the project,<br />

which showed that people living<br />

around nuclear power plants tend to<br />

have more trust in nuclear projects.<br />

“Trust has been one cornerstone<br />

in being able to proceed according to<br />

the Government’s schedule,” Jalonen<br />

said. “Building trust has required<br />

extensive and open communication<br />

with local people, the authority and<br />

the decision makers.”<br />

The project is based on the “multiple<br />

barriers” concept, which aims to<br />

provide needed containment and<br />

isolation to prevent spent fuel from<br />

leaking and spreading, according to<br />

Posiva. The combination of bedrock,<br />

disposal canisters surrounded by clay,<br />

tunnels filled with clay containing<br />

backfilling materials and plugging the<br />

tunnel’s mouth will all serve as protective<br />

multiple barriers.<br />

Who’s next?<br />

Two other countries have made progress<br />

towards building repositories for<br />

high-level radioactive waste or spent<br />

fuel declared as waste. In June 2016,<br />

the Swedish Radiation Safety Authority<br />

endorsed the licence application<br />

for the future spent fuel deep geological<br />

repository at Forsmark. Review by<br />

the Swedish Land and Environment<br />

Court for environmental licencing of<br />

the project started in September 2017.<br />

In France, the licence application<br />

for the deep geological disposal<br />

facility, Cigéo, is under preparation; it<br />

is planned to be submitted by the end<br />

of <strong>2018</strong>, with construction starting in<br />

2<strong>02</strong>0. The pilot phase of disposal<br />

could start as soon as 2<strong>02</strong>5. It will<br />

contain waste from the reprocessing<br />

of spent fuel from France’s current<br />

fleet of nuclear power plants and<br />

other long-lived radioactive waste.<br />

The science<br />

High-Level Radioactive Waste (HLW)<br />

is produced from the burning of<br />

uranium fuel in nuclear power reactors.<br />

It is of two kinds: spent fuel,<br />

declared as waste and ready for<br />

disposal, or waste resulting from the<br />

reprocessing of spent fuel.<br />

Due to its high radioactivity and<br />

very long half-life (the time it takes<br />

for a radioactive substance to lose half<br />

its radioactivity), HLW has to be well<br />

contained and isolated from the human<br />

environment. Intensive research<br />

has identified the suitability of various<br />

rock types to host deep geological repositories<br />

and engineered barrier systems<br />

to isolate the waste. These repositories<br />

are constructed in suitable geological<br />

formations at a depth of several<br />

hundred meters and designed to<br />

contain high-level waste for hundreds<br />

of thousands of years.<br />

| | www.iaea.org<br />

Reactors<br />

Georgia’s commitment to<br />

new nuclear a win for US<br />

economy, environment<br />

(nei) In response to the announcement<br />

that the Georgia Public Service Commission<br />

unanimously approved an<br />

order allowing continued construction<br />

of two additional reactors at Plant<br />

Vogtle, the following is a statement by<br />

NEI President and CEO Maria Korsnick.<br />

“Completing the Plant Vogtle expansion<br />

is good for America on many<br />

levels, especially in terms of our<br />

national security, our commitment to a<br />

cleaner environment, and energy<br />

diversity. In addition to the thousands<br />

of workers who will cheer this decision,<br />

these nuclear facilities when<br />

completed will produce decades worth<br />

of clean, reliable power and provide<br />

billions of dollars in economic benefits.<br />

“Demonstrating we can build and<br />

complete new nuclear plants here in<br />

America will help us regain our<br />

leader ship in a technology we invented.<br />

America’s pre-eminence in<br />

nuclear energy makes our country<br />

safer because it allows us to influence<br />

and control how this technology is<br />

used around the world.”<br />

| | www.nei.com<br />

Finnish cities to explore Small<br />

Modular Reactors for district<br />

heating<br />

(nucnet) The Finnish cities of Helsinki,<br />

Espoo and Kirkkonummi have begun<br />

studies to find out if it would be<br />

feasible to replace coal and natural<br />

gas in district heating with small<br />

modular nuclear reactors (SMRs), the<br />

environmental group Ecomodernist<br />

Society of Finland said. The society<br />

said a feasibility study will be carried<br />

out into the potential for SMRs to<br />

replace fossil fuel-burning in cities<br />

around the Helsinki metropolitan<br />

area. Several advanced SMRs are in<br />

development and coming to market by<br />

2030 that could meet the specifications,<br />

the society said. Most of the<br />

district heating in Finland is produced<br />

129<br />

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News


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

130<br />

NEWS<br />

*)<br />

Net-based values<br />

(Czech and Swiss<br />

nuclear power<br />

plants gross-based)<br />

1)<br />

Refueling<br />

2)<br />

Inspection<br />

3)<br />

Repair<br />

4)<br />

Stretch-out-operation<br />

5)<br />

Stretch-in-operation<br />

6)<br />

Hereof traction supply<br />

7)<br />

Incl. steam supply<br />

8)<br />

New nominal<br />

capacity since<br />

January 2016<br />

9)<br />

Data for the Leibstadt<br />

(CH) NPP will<br />

be published in a<br />

further issue of <strong>atw</strong><br />

BWR: Boiling<br />

Water Reactor<br />

PWR: Pressurised<br />

Water Reactor<br />

Source: VGB<br />

by burning coal, natural gas, wood<br />

fuels and peat. While many Finnish<br />

cities have progressive climate policies<br />

and goals, they have struggled to<br />

decarbonise heating and liquid fuels,<br />

the society said. Rauli Partanen,<br />

vice-chair of the society and an independent<br />

energy analyst and author,<br />

said there are “significant economic<br />

possibilities” in producing combined<br />

heat and power (CHP) with nuclear<br />

reactors. He said: “With CHP, the<br />

reactor could produce roughly twice<br />

the value per installed capacity compared<br />

with just electricity production,<br />

while at the same time decarbonising<br />

heat production.” He said nuclear<br />

is great for baseload needs, but<br />

with advanced technologies such as<br />

high temperature reactors and high<br />

temperature electrolysis, nuclear can<br />

also be used to decarbonise not just<br />

electricity, heat but also transportation<br />

fuels and many industries”.<br />

| | www.vtt.fi<br />

EDF ‘Cannot build new<br />

reactors in France without<br />

guarantees’<br />

(nucnet) French state-controlled<br />

utility EDF can no longer build new<br />

nuclear reactors in France without<br />

state support, chief executive officer<br />

Jean-Bernard Levy was quoted as<br />

saying in an interview with the Ouest<br />

France daily newspaper. Asked when<br />

EDF could build new reactors at home,<br />

Mr Levy said: “Henceforth, we cannot<br />

build new reactors without adequate<br />

regulation providing guaranteed<br />

income”. He said the Flamanville-3<br />

EPR project under construction in<br />

northern France began at a time of<br />

high power prices and that now all<br />

power sources, nuclear as well as<br />

renewables, need to get “the same<br />

visibility on sales prices”. For its<br />

project to build two EPRs at Hinkley<br />

Point in the UK, EDF obtained an<br />

EU-approved state-guaranteed price<br />

of £92.5 per MWh over 35 years,<br />

which is above current market prices.<br />

The government of French president<br />

Emmanuel Macron is planning to close<br />

old reactors to reduce the share of nuclear<br />

energy in French power generation<br />

to 50% by around 2035 from 75 %<br />

today. Mr Levy said EDF expects to get<br />

approval to load nuclear fuel at<br />

Flamanville-3 at the end of <strong>2018</strong>.<br />

| | www.edf.com<br />

Japan’s Regulator:<br />

Kashiwazaki Kariwa-6 and -7<br />

meet new safety standards<br />

(nucnet) Units 6 and 7 of the<br />

Kashiwazaki Kariwa nuclear power<br />

station in Niigata Prefecture, northwestern<br />

Japan, meet new regulatory<br />

standards imposed after the March<br />

2011 Fukushima-Daiichi accident, the<br />

Nuclear Regulation Authority said.<br />

The two units, owned and operated<br />

by Tokyo Electric Power Company<br />

(Tepco) are the first boiling water<br />

reactors to meet the new standards.<br />

Tepco also owns the Fukushima-<br />

Daiichi station.<br />

Kashiwazaki Kariwa was not affected<br />

by the March 2011 earthquake and<br />

tsunami which damaged Fukushima-<br />

Daiichi, although the station’s seven<br />

reactors had all been offline for up to<br />

three years following a 2007 earthquake<br />

which damaged the site but did<br />

not damage the reactors themselves.<br />

While the units were offline, work<br />

was carried out to improve the<br />

facility’s earthquake resistance.<br />

Accord ing to JAIF, the governor of<br />

Niigata Prefecture, Ryuichi Yoneyama,<br />

has said he will not discuss restarting<br />

the two units until further information<br />

about nuclear incidents and their<br />

impact on public health is made available.<br />

Both units are 1,315-MW BWRS.<br />

Kashiwazaki Kariwa-6 began commercial<br />

operation in November 1996 and<br />

Kashiwazaki Kariwa-7 in July 1997.<br />

Tokyo-based nuclear industry<br />

group the Japan Atomic Industrial<br />

Forum said 14 nuclear units have now<br />

been approved by the NRA as meeting<br />

the new standards. They are<br />

Kashiwazaki Kariwa-6 and -7,<br />

Operating Results October 2017 (corrigendum, <strong>atw</strong> 1 (<strong>2018</strong>) p. 58)<br />

Plant name<br />

Type<br />

Nominal<br />

capacity<br />

gross<br />

[MW]<br />

net<br />

[MW]<br />

Operating<br />

time<br />

generator<br />

[h]<br />

Energy generated, gross<br />

[MWh]<br />

Time availability<br />

[%]<br />

Energy availability<br />

[%] *) Energy utilisation<br />

[%] *)<br />

Month Year Since Month Year Month Year Month Year<br />

commissioning<br />

KBR Brokdorf DWR 1480 1410 745 937 223 3 903 011 338 316 924 100.00 41.98 93.94 39.11 84.59 35.98<br />

KKE Emsland 4) DWR 1406 1335 745 1 004 762 9 304 398 333 303 977 100.00 91.93 99.93 91.77 95.81 90.70<br />

KWG Grohnde DWR 1430 1360 745 970 799 8 126 396 365 069 095 100.00 87.01 94.85 83.35 90.42 77.21<br />

KRB B Gundremmingen 4) SWR 1344 1284 745 778 570 8 351 414 330 004 358 100.00 91.83 100.00 90.98 76.78 84.52<br />

KRB C Gundremmingen SWR 1344 1288 745 968 428 7 990 831 318 640 904 100.00 85.41 99.83 83.30 96.32 81.<strong>02</strong><br />

KKI-2 Isar DWR 1485 1410 745 1 073 129 9 378 353 339 453 163 100.00 89.84 99.71 89.37 96.66 86.22<br />

KKP-2 Philippsburg DWR 1468 14<strong>02</strong> 745 1 046 248 5 745 846 353 059 535 100.00 55.80 99.92 55.72 94.15 52.80<br />

GKN-II Neckarwestheim DWR 1400 1310 745 1 011 300 8 549 400 318 131 734 100.00 86.71 99.50 86.46 97.13 83.84<br />

Operating Results November 2017<br />

Plant name<br />

Type<br />

Nominal<br />

capacity<br />

gross<br />

[MW]<br />

net<br />

[MW]<br />

Operating<br />

time<br />

generator<br />

[h]<br />

Energy generated, gross<br />

[MWh]<br />

Time availability<br />

[%]<br />

Energy availability Energy utilisation<br />

[%] *) [%] *)<br />

Month Year Since Month Year Month Year Month Year<br />

commissioning<br />

KBR Brokdorf DWR 1480 1410 720 942 685 4 845 695 339 259 608 100.00 47.20 93.97 44.04 88.16 40.67<br />

KKE Emsland 4) DWR 1406 1335 720 1 017 448 10 321 846 334 321 425 100.00 92.65 99.77 92.49 100.61 91.59<br />

KWG Grohnde DWR 1430 1360 446 586 675 8 713 070 365 655 769 61.99 84.77 56.84 80.97 56.57 75.35<br />

KRB B Gundremmingen 4) SWR 1344 1284 720 701 347 9 052 761 330 705 705 100.00 92.56 98.85 91.69 71.32 83.33<br />

KRB C Gundremmingen SWR 1344 1288 720 956 516 8 947 347 319 597 420 100.00 86.72 98.05 84.62 98.30 82.57<br />

KKI-2 Isar DWR 1485 1410 720 1 061 544 10 439 897 340 514 707 100.00 90.75 100.00 90.33 99.05 87.37<br />

KKP-2 Philippsburg DWR 1468 14<strong>02</strong> 720 1 042 562 6 788 408 354 1<strong>02</strong> 097 100.00 59.77 100.00 59.69 97.08 56.77<br />

GKN-II Neckarwestheim DWR 1400 1310 720 996 000 9 545 400 319 127 734 100.00 87.91 98.51 87.54 99.08 85.21<br />

News


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

Mihama 3, Takahama-1, -2, -3 and -4,<br />

and Ohi-3 and -4, Ikata-3, Genkai-3<br />

and -4 and Sendai-1 and -2.<br />

All of Japan’s 48 reactors were shut<br />

between 2011 and 2012 after the<br />

Fukushima-Daiichi accident. Five<br />

units have resumed commercial operation.<br />

They are: Takahama-3 and -4,<br />

Ikata-3 and Sendai-1 and -2.<br />

Before the Fukushima-Daiichi<br />

accident Japan had generated around<br />

30% of its electricity with plans to<br />

increase the share to 40%. According<br />

to the International Atomic Energy<br />

Agency Japan’s nuclear share in 2016<br />

was 2.15%.<br />

| | www.tepco.co.jp, www.nsr.go.jp<br />

Slovakia: Mochovce-3 startup<br />

target of end <strong>2018</strong> is realistic<br />

(se) The schedule for the completion<br />

of the third and fourth units of the<br />

Mochovce nuclear power station in<br />

Slovakia is realistic, with Unit 3 likely<br />

to begin commercial operation at the<br />

end of <strong>2018</strong> and Unit 4 at the end of<br />

2019, regulator UJD said. According<br />

to utility Slovenské Elektrárne, fuel<br />

will be loaded into Unit 3 in July <strong>2018</strong>.<br />

Preparations have begun for the start<br />

of a cold pressure test of the primary<br />

circuit at Unit 3, local media reports<br />

said. In June 2016 the utility said construction<br />

work at Unit 3 was “more<br />

than 92%” finished, with Unit 4 at<br />

75%. Mochovce-3 and -4 are both<br />

440-MW pressurised water reactors of<br />

the Russian VVER V-213 design.<br />

| | www.seas.sk<br />

Plans for UK new nuclear<br />

move forward as regulator<br />

approves design for UK-ABWR<br />

(nucnet) Plans for two new nuclear<br />

power stations in the UK have taken a<br />

crucial step forward as UK regulators<br />

approved the design of the reactor<br />

technology for the projects. The Office<br />

for Nuclear Regulation gave the green<br />

light today for the UK Advanced<br />

Boiling Water Reactor (UK-ABWR),<br />

designed by Hitachi-GE. The ONR<br />

said the design is suitable for construction<br />

in the UK, marking the end<br />

of a five-year regulatory process.<br />

Horizon Nuclear Power is proposing<br />

to build and operate two of these<br />

reactors in Wylfa Newydd on Anglesey<br />

and Oldbury-on-Severn in Gloucestershire.<br />

Duncan Hawthorne, Horizon’s<br />

chief executive, said: “This is a huge<br />

milestone for Horizon and a major<br />

leap forward for us in bringing<br />

much-needed new nuclear power to<br />

the UK.” Horizon said today that<br />

“steady progress” is being made with<br />

the Hitachi-backed Wylfa Newydd<br />

project, including the submission of<br />

the site licence application and completion<br />

of a third public consultation.<br />

Attention will now turn to financing<br />

the Wylfa Newydd project. Earlier this<br />

year Horizon said: “We have always<br />

been clear that we are looking to bring<br />

other investors into Horizon. Based on<br />

the strengths of our project, we are in<br />

positive discussions with a number of<br />

parties but we will not be commenting<br />

on the process whilst it is ongoing.”<br />

| | www.onr.ork.uk,<br />

www.hitachi-hgne-uk-abwr.co.uk<br />

Company News<br />

Framatome pursues the<br />

industrial and technological<br />

adventure of the nuclear<br />

energy business<br />

(framatome) New NP, a subsidiary of<br />

AREVA NP, becomes Framatome, a<br />

company whose capital is owned by<br />

the EDF group (75.5%), Mitsubishi<br />

Heavy Industries (MHI – 19.5%) and<br />

Assystem (5 %).<br />

Framatome confirms its recognized<br />

manufacturer’s ambition: being the<br />

sup plier of safe and competitive nuclear<br />

solutions, supporting its electrical<br />

utility customers all over the world.<br />

Framatome, 14,000 employees<br />

worldwide<br />

Framatome employees have recognized<br />

skills, a know-how that was<br />

forged over the long history of the<br />

company and that has enabled us to<br />

build outstanding industrial success in<br />

France and internationally. Framatome<br />

places its faith in the expertise<br />

of the women and the men who are at<br />

its very core: this expertise underpins<br />

the company’s strategy and is key to<br />

serving the needs of its customers and<br />

furthering the success of the nuclear<br />

industry.<br />

In the words of Bernard Fontana,<br />

Chairman of the Managing Board and<br />

Chief Executive Officer of Framatome,<br />

“Framatome possesses unique knowhow<br />

in an industry that today is and<br />

will remain key for a low-carbon<br />

energy mix. Our employees in France<br />

and around the world have been able<br />

to face considerable challenges in<br />

recent years. As we emerge from this<br />

transition phase, I share their pride<br />

and I want to thank them for all<br />

the work they have accomplished.<br />

Steeped in a rich heritage, Framatome<br />

is today one of the reference players in<br />

the nuclear sector worldwide, benefiting<br />

from unparalleled operating<br />

feedback. Our ambition is delivering a<br />

level of industrial excellence that is<br />

recognized by our customers.”<br />

Proud of its core business expertise<br />

as designer, supplier and installer of<br />

nuclear steam supply systems Framatome<br />

contributes to the design of<br />

power plants, supplies the nuclear<br />

steam supply system, designs and<br />

manufactures components and fuels,<br />

integrates the instrumentation and<br />

control systems and carries out the<br />

maintenance of in-service nuclear<br />

reactors. It delivers its high-performance<br />

products and services to<br />

customers all over the world.<br />

Framatome is a technology company,<br />

holding around 3,500 patents<br />

covering some 680 inventions, which<br />

serve the most demanding needs of its<br />

customers who number among the<br />

key international energy leaders.<br />

Framatome operates on more than<br />

250 reactors worldwide.<br />

An internationally-focused strategy<br />

of development and industrial excellence<br />

Framatome has the determination<br />

to go further in terms of industrial<br />

excellence, leveraging five strategic<br />

axes: proven and sustainable expertise,<br />

performance in delivering, an<br />

agile and adaptive organization, safe<br />

and competitive solutions and international<br />

development. With an existing<br />

global fleet of some 440 reactors<br />

representing output of around<br />

390 GWe in 31 countries, and with<br />

new nuclear capacity on its way, the<br />

nuclear market presents opportunities<br />

in the areas of components, fuel, retrofits<br />

and services. (18191512)<br />

| | www.framatome.com<br />

Brookfield to acquire Westinghouse<br />

Electric Company<br />

(westn) Westinghouse Electric Company,<br />

the global leader in nuclear<br />

technology, fuel and services, has<br />

agreed to be acquired by Brookfield<br />

Business Partners L.P. (NYSE:BBU)<br />

(TSX:BBU.UN) together with institutional<br />

partners (collectively, “Brookfield”)<br />

for approximately $ 4.6 billion.<br />

The purchase price for substan tially<br />

all of the global business of Westinghouse<br />

Electric Company LLC and its<br />

affiliated debtors and debtors- in-posses<br />

sion (collectively “Westinghouse”)<br />

excludes cash, but includes the assumption<br />

of certain pension, environmental<br />

and other operating obligations.<br />

“Brookfield’s acquisition of Westinghouse<br />

reaffirms our position as the<br />

leader of the global nuclear industry,”<br />

said Westinghouse President & CEO<br />

José Emeterio Gutiérrez. “Our transformation<br />

and strategic restructuring<br />

131<br />

NEWS<br />

News


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

132<br />

NEWS<br />

process is creating a stronger, stable,<br />

and more streamlined global Westinghouse<br />

business, for the benefit of our<br />

customers and employees.”<br />

Brookfield’s acquisition of Westinghouse<br />

is expected to close in the third<br />

quarter of <strong>2018</strong>, subject to Bankruptcy<br />

Court approval and customary closing<br />

conditions including, among others,<br />

regulatory approvals. Throughout the<br />

process, Westinghouse will continue<br />

to operate in the ordinary course of<br />

business under its existing senior<br />

management.<br />

PJT Partners is the financial advisor<br />

to Westinghouse, Weil, Gotshal &<br />

Manges LLP is Westinghouse’s legal<br />

counsel, and AlixPartners LLP is Westinghouse’s<br />

turnaround consultant.<br />

| | www.westinghousenuclear.com,<br />

www.brookfield.com<br />

People<br />

Appointment of the<br />

Framatome Managing Board<br />

(framatome) The Supervisory Board<br />

of Framatome, meeting under the<br />

chairmanship of Jean-Bernard Lévy,<br />

Chairman and CEO of EDF, appointed<br />

Some Questions and Answers About Energy.<br />

Answers<br />

1b. False: All leading scenarios predict a rise of the global<br />

energy demand for the next decades (2015 to 2040:<br />

between 10 % to 40 %) mainly driven by the increase<br />

of the population and the growing demand in developing<br />

countries.<br />

2b. False: All leading scenarios predict an over proportional rise<br />

of the global electricity demand for the next decades (2015<br />

to 2040: between 60 % to 80 %) mainly driven by the<br />

increase of the population, the growing demand in<br />

developing countries and the today’s poor access to<br />

electricity for about one third of the world’s population.<br />

3b. False: In 2017 the global coal production increased by 2 %<br />

compared with the previous year 2016.<br />

4c. Since 2010 about 11 % of world’s electricity demand is<br />

produced in nuclear power plants.<br />

5b. About 5 % of world’s electricity demand was produced by<br />

wind (4 %) and solar (1 %) in 2017.<br />

6c. United States, with about 6,800 billions of tonnes,<br />

98 % thereof coal; EU about 530 billions of tonnes,<br />

95 % thereof coal<br />

7d. China. The carbon dioxide emission are always twice<br />

the emissions of the USA and three times the emissions<br />

of all 28 EU countries.<br />

8d. Hydropower, 4 to 13 g CO 2 per kWh.<br />

Wind and nuclear: about 8 to 20 g CO 2 per kWh.<br />

Photovoltaics: 35 to 160 g CO 2 per kWh.<br />

9a. Nuclear power, especially small modular reactors<br />

with advanced fuel usage.<br />

10d. Nuclear power. The number of lost lifetime-days per<br />

kilowatt-hour produced from nuclear power is in the range<br />

of wind power and about 5- to 100-times lower than of<br />

every other primary energy source.<br />

11d. The natural radiation caused by Thorium and its decay<br />

products in Guarapari (Monazit area) is up to<br />

10,000-times higher than the radiation from nuclear<br />

reactors in normal operation.<br />

12b. False: There are 448 nuclear power plants in operation<br />

worldwide and 59 under construction. About 120 additional<br />

power plants are planned. Only some plants will be shutdown<br />

in the upcoming year, mainly in the „old“ countries.<br />

Further expansion programmes are under the way e.g. in<br />

China with more than 100 plants to be in operation in the<br />

period 2030 to 2040 and the „Newcomer“ countries in Asia.<br />

Bernard Fontana Chairman of the<br />

Managing Board and Chief Executive<br />

Officer.<br />

It also appointed Philippe Braidy<br />

Managing Director, member of the<br />

Managing Board.<br />

Bernard Fontana holds a degree in<br />

engineering from the École Polytechnique<br />

and the École Nationale<br />

Supérieure des Techniques Avancées<br />

in Paris. He has 30 years’ experience<br />

in the chemical, steel and building<br />

materials industries (SNPE, Arcelor-<br />

Mittal, APERAM and Holcim).<br />

From February 2012 to September<br />

2015, he served as CEO of Holcim Ltd.<br />

Since September 1, 2015, Bernard<br />

Fontana had been Chief Executive<br />

Officer of AREVA NP.<br />

Philippe Braidy, former Head of<br />

regional and local Development and<br />

network in French Caisse des Dépôts,<br />

has 30 years’ experience as Technical<br />

and Financial Director in public<br />

administrations (French Ministry<br />

of Budget, Prime minister’s office,<br />

CEA…). Up to now he has been<br />

managing the Finance, Strategy/Innovation/Communications,<br />

Legal/Compliance,<br />

Risks/Audit, and Information<br />

Systems Functions of AREVA NP.<br />

| | www.framatome.com<br />

Einige Fragen und Antworten zum Thema Energie.<br />

Die Antworten<br />

1b. Falsch: Alle führenden Szenarien prognostizieren einen Anstieg<br />

des globalen Energiebedarfs für die nächsten Jahrzehnte (2015<br />

bis 2040: zwischen 10 % und 40 %), der vor allem durch das<br />

Bevölkerungswachstum und die wachsende Nachfrage an<br />

Energie in den sich entwickelnden Ländern getrieben wird.<br />

2b. Falsch: Alle führenden Szenarien prognostizieren für die nächsten<br />

Jahrzehnte einen überpropor tio nalen Anstieg des weltweiten<br />

Strombedarfs (2015 bis 2040: zwischen 60 % und 80 %), der<br />

vor allem durch das Bevölkerungswachstum, die wachsende<br />

Nachfrage in den sich entwickelnden Ländern und dem heute<br />

fehlenden Zugang zu Elektrizität für etwa ein Drittel der Weltbevölkerung<br />

bedingt ist.<br />

3b. Falsch: Im Jahr 2017 stieg die weltweite Kohle förderung<br />

im Vergleich zum Vorjahr 2016 um 2 %.<br />

4c. Seit 2010 werden rund 11 % des weltweiten Strombedarfs<br />

in Kernkraftwerken erzeugt.<br />

5b. Rund 5 % des weltweiten Strombedarfs wurden 2017<br />

durch Wind (4 %) und Solarenergie (1 %) erzeugt.<br />

6c. USA mit rund 6.800 Mrd. t, davon 98 % Kohle;<br />

EU mit rund 530 Mrd. t, davon 95 % Kohle<br />

7d. China. Die Kohlendioxid-Emissionen sind doppelt so hoch wie<br />

die der USA und dreimal so hoch wie die aller 28 EU-Länder.<br />

8d. Wasserkraft, 4 bis 13 g CO 2 pro kWh.<br />

Wind und Atomkraft: ca. 8 bis 20 g CO 2 pro kWh.<br />

Photovoltaik: 35 bis 160 g CO 2 pro kWh.<br />

9a. Kernkraft, insbesondere kleine modulare Reaktoren<br />

mit fortschrittlichem Brennstoff.<br />

10d. Kernenergie. Die Anzahl der Ausfalltage pro Kilowatt stunde<br />

aus Kernenergie liegt im Bereich der Windkraft und<br />

etwa 5- bis 100-mal niedriger als bei jeder anderen<br />

Primärenergiequelle.<br />

11d. Die natürliche Strahlung, die Thorium und seine Zerfalls produkte<br />

in Guarapari (Monazit-Gebiet) verursachen, ist bis zu<br />

10.000-mal höher als die Strahlung aus Kernkraftwerken<br />

im Normalbetrieb.<br />

12b. Falsch: Weltweit sind 448 Kernkraftwerke in Betrieb und<br />

59 in Bau; rund 120 weitere Kraftwerke sind geplant.<br />

Nur einige Anlagen werden in den kommenden Jahren<br />

stillgelegt werden, vor allem in den “alten” Ländern.<br />

Weitere Ausbauprogramme werden verfolgt und umgesetzt,<br />

z.B. in China mit mehr als 100 Anlagen, die im Zeitraum<br />

2030 bis 2040 in Betrieb sein werden, sowie in den<br />

“Newcomer”-Ländern Asiens.<br />

Market data<br />

(All information is supplied without<br />

guarantee.)<br />

Nuclear Fuel Supply<br />

Market Data<br />

Information in current (nominal)<br />

U.S.-$. No inflation adjustment of<br />

prices on a base year. Separative work<br />

data for the formerly “secondary<br />

market”. Uranium prices [US-$/lb<br />

U 3 O 8 ; 1 lb = 453.53 g; 1 lb U 3 O 8 =<br />

0.385 kg U]. Conversion prices<br />

[US-$/kg U], Separative work<br />

[US-$/SWU (Separative work unit)].<br />

January to December 2013<br />

• Uranium: 34.00–43.50<br />

• Conversion: 9.25–11.50<br />

• Separative work: 98.00–127.00<br />

January to December 2014<br />

• Uranium: 28.10–42.00<br />

• Conversion: 7.25–11.00<br />

• Separative work: 86.00–98.00<br />

January to June 2015<br />

• Uranium: 35.00–39.75<br />

• Conversion: 7.00–9.50<br />

• Separative work: 70.00–92.00<br />

June to December 2015<br />

• Uranium: 35.00–37.45<br />

• Conversion: 6.25–8.00<br />

• Separative work: 58.00–76.00<br />

2016<br />

January to June 2016<br />

• Uranium: 26.50–35.25<br />

• Conversion: 6.25–6.75<br />

• Separative work: 58.00–62.00<br />

July to December 2016<br />

• Uranium: 18.75–27.80<br />

• Conversion: 5.50–6.50<br />

• Separative work: 47.00–62.00<br />

2017<br />

January 2017<br />

• Uranium: 20.25–25.50<br />

• Conversion: 5.50–6.75<br />

• Separative work: 47.00–50.00<br />

February 2017<br />

• Uranium: 23.50–26.50<br />

• Conversion: 5.50–6.75<br />

• Separative work: 48.00–50.00<br />

March 2017<br />

• Uranium: 24.00–26.00<br />

• Conversion: 5.50–6.75<br />

• Separative work: 47.00–50.00<br />

April 2017<br />

• Uranium: 22.50–23.50<br />

• Conversion: 5.00–5.50<br />

• Separative work: 45.50–48.50<br />

May 2017<br />

• Uranium: 19.25–22.75<br />

• Conversion: 5.00–5.50<br />

• Separative work: 42.00–45.00<br />

June 2017<br />

• Uranium: 19.25–20.50<br />

• Conversion: 5.55–5.50<br />

• Separative work: 42.00–43.00<br />

News


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

July 2017<br />

• Uranium: 19.75–20.50<br />

• Conversion: 4.75–5.25<br />

• Separative work: 42.00–43.00<br />

August 2017<br />

• Uranium: 19.50–21.00<br />

• Conversion: 4.75–5.25<br />

• Separative work: 41.00–43.00<br />

September 2017<br />

• Uranium: 19.75–20.75<br />

• Conversion: 4.60–5.10<br />

• Separative work: 40.50–42.00<br />

October 2017<br />

• Uranium: 19.90–20.50<br />

• Conversion: 4.50–5.25<br />

• Separative work: 40.00–43.00<br />

November 2017<br />

• Uranium: 20.00–26.00<br />

• Conversion: 4.75–5.25<br />

• Separative work: 40.00–43.00<br />

December 2017<br />

• Uranium: 23.50–25.50<br />

• Conversion: 5.00–6.00<br />

• Separative work: 39.00–42.00<br />

| | Source: Energy Intelligence<br />

www.energyintel.com<br />

Cross-border Price<br />

for Hard Coal<br />

Cross-border price for hard coal in<br />

[€/t TCE] and orders in [t TCE] for<br />

use in power plants (TCE: tonnes of<br />

coal equivalent, German border):<br />

2012: 93.<strong>02</strong>; 27,453,635<br />

2013: 79.12, 31,637,166<br />

2014: 72.94, 30,591,663<br />

2015: 67.90; 28,919,230<br />

2016: 67.07; 29,787,178<br />

I. quarter: 56.87; 8,627,347<br />

II. quarter: 56.12; 5,970,240<br />

III. quarter: 65.03, 7.257.041<br />

IV. quarter: 88.28; 7,932,550<br />

2017:<br />

I. quarter: 95.75; 8,385,071<br />

II. quarter: 86.40; 5,094,233<br />

III. quarter: 88.07; 5,504,908<br />

| | Source: BAFA, some data provisional<br />

www.bafa.de<br />

EEX Trading Results<br />

December 2017<br />

(eex) In December 2017, the European<br />

Energy Exchange (EEX) achieved a<br />

total volume of 234.5 TWh on its<br />

power derivatives markets (December<br />

2016: 287.4 TWh). The December<br />

volume comprised 160.8 TWh traded<br />

at EEX via Trade Registration with<br />

subsequent clearing. Clearing and<br />

settlement of all exchange transactions<br />

was executed by European<br />

Commodity Clearing (ECC).<br />

On the German power derivatives<br />

market, trading volumes in Phelix-<br />

DE Futures (72.9 TWh) exceeded<br />

| | Uranium spot market prices from 1980 to 2017 and from 2007 to <strong>2018</strong>. The price range is shown.<br />

In years with U.S. trade restrictions the unrestricted uranium spot market price is shown.<br />

| | Separative work and conversion market price ranges from 2007 to <strong>2018</strong>. The price range is shown.<br />

)1<br />

In December 2009 Energy Intelligence changed the method of calculation for spot market prices. The change results in virtual price leaps.<br />

Phelix- DE/AT Futures (66.0 TWh) for<br />

the first time. On the markets for Italy<br />

(50.0 TWh) and Spain (7.4 TWh),<br />

EEX recorded the highest monthly<br />

volume of the year 2017. Compared to<br />

the previous year, volumes in these<br />

markets increased by 43% (Italy) and<br />

10% (Spain). On the Dutch power<br />

derivatives market, trading volumes<br />

almost doubled to 1.8 TWh (December<br />

2016: 0.9 TWh).<br />

The Settlement Price for base<br />

load contract (Phelix Futures) with<br />

delivery in <strong>2018</strong> amounted to<br />

37.67 €/MWh. The Settlement Price<br />

for peak load contract (Phelix Futures)<br />

with delivery in <strong>2018</strong> amounted to<br />

46.80 €/MWh.<br />

On the EEX markets for emission<br />

allowances, 65.6 million tonnes of<br />

CO 2 were traded in December<br />

( December 2016: 117.6 million tonnes<br />

of CO 2 ). Primary market auctions<br />

contributed 45.0 million tonnes of<br />

CO 2 to the total volume.<br />

The EUA price with delivery in<br />

December 2017 amounted to<br />

7.10/8.21 €/ EUA (min./max.).<br />

| | www.eex.com<br />

MWV Crude Oil/Product Prices<br />

November 2017<br />

(mwv) According to information and<br />

calculations by the Association of the<br />

German Petroleum Industry MWV e.V.<br />

in November 2017 the prices for super<br />

fuel, fuel oil and heating oil noted<br />

slightly higher compared with the<br />

pre vious month October 2017. The<br />

average gas station prices for Euro<br />

super consisted of 138.54 €Cent<br />

( October 2017: 134.72 €Cent, approx.<br />

+2.84 % in brackets: each information<br />

for pre vious month or rather previous<br />

month comparison), for diesel fuel of<br />

118.52 €Cent (116.196; +2.01 %) and<br />

for heating oil (HEL) of 60.06 €Cent<br />

(57.07 €Cent, +5.24 %).<br />

The tax share for super with<br />

a consumer price of 138.54 €Cent<br />

(134.72 €Cent) consisted of<br />

65.45 €Cent (47.24 %, 65.45 €Cent)<br />

for the current constant mineral oil<br />

tax share and 22.12 €Cent (current<br />

rate: 19.0 % = const., 21.51 €Cent) for<br />

the value added tax. The product<br />

price (notation Rotterdam) consisted<br />

of 39.06 €Cent (28.19 %, 36.20 €Cent)<br />

and the gross margin consisted of<br />

11.91 €Cent (8.60 %; 11.74 €Cent).<br />

Thus the overall tax share for super<br />

results of 66.24 % (67.58 %).<br />

Worldwide crude oil prices<br />

(monthly average price OPEC/Brent/<br />

WTI, Source: U.S. EIA) were again<br />

higher, approx. +9.43 % (+3.27 %)<br />

in November compared to October<br />

2017.<br />

The market showed a stable<br />

development with higher prices; each<br />

in US-$/bbl: OPEC basket: 60.74<br />

(53.44); UK-Brent: 62.70 (57.51);<br />

West Texas Inter mediate (WTI):<br />

56.64 (51.58).<br />

| | www.mwv.de<br />

133<br />

NEWS<br />

News


<strong>atw</strong> Vol. 63 (<strong>2018</strong>) | Issue 2 ı February<br />

134<br />

NUCLEAR TODAY<br />

Links to reference<br />

sources:<br />

President Macron<br />

interview: http://<br />

reut.rs/2EIkEgM<br />

Trump on Iran: http://<br />

nyti.ms/2mF1Ecp<br />

UK statement on<br />

Euratom: http://bit.ly/<br />

2mGhrbf<br />

Author<br />

John Shepherd<br />

nuclear 24<br />

41a Beoley Road West<br />

St George’s<br />

Redditch B98 8LR,<br />

United Kingdom<br />

Playing Politics with Nuclear<br />

is All Part of the Game<br />

John Shepherd<br />

If a week is a long time in politics – a statement attributed to former British prime minister Harold Wilson – then what<br />

about a month, or several months? Just eight months ago, Emmanuel Macron was elected president of France. Among<br />

his portfolio of political pledges was one to respect reductions in the country’s nuclear park set out by his predecessor,<br />

Francois Hollande.<br />

Hollande’s administration had established an energy<br />

transition law which set a target of reducing the share of<br />

nuclear in France’s electricity mix to 50 % by 2<strong>02</strong>5 from<br />

around 75 %.<br />

Fast forward to November 2017 and Macron’s environment<br />

minister, Nicolas Hulot, admitted that this could not<br />

be done – at least in the timeframe envisaged – without<br />

pushing up CO2 emissions, endangering security of power<br />

supply and the not-so-insignificant matter of risking<br />

thousands of jobs. Instead, Hulot said the government<br />

would come up with a more “realistic” target.<br />

Now move forward into early <strong>2018</strong> and France has<br />

signed a deal for closer cooperation in the development of<br />

civil nuclear with the China National Nuclear Corporation<br />

(CNNC). The agreement, signed by Framatome and CNNC<br />

during Macron’s visit to Beijing in January, also renewed a<br />

contract under which Framatome will supply nuclear fuel<br />

components to CNNC.<br />

As Macron’s visit came to a close, he issued a joint statement<br />

with his Chinese counterpart, Xi Jinping, to express<br />

“their high appreciation of the active cooperation between<br />

the two countries in the field of civilian nuclear energy and<br />

support a deepening of cooperation in the entire nuclear<br />

cycle”.<br />

Now this was indeed good news. France has had more<br />

than its fair share of ups and downs in the state-backed<br />

nuclear sector in recent years. But it begs the question, why<br />

would Macron want to expand civil nuclear activities in<br />

cooperation with an overseas partner if, back home, the<br />

goal is to reduce the reliance on nuclear?<br />

The answer is politics. As Macron was quoted telling<br />

France 2 television in an interview last December: “I don’t<br />

idolise nuclear energy at all. But I think you have to pick<br />

your battle. My priority in France, Europe and internationally<br />

is CO 2 emissions and (global) warming.”<br />

A leader who certainly does not shy away from battles is<br />

US president Donald Trump, who has also had nuclear<br />

power in his sights – but he too gives mixed messages on<br />

nuclear.<br />

On the domestic front, President Trump has been<br />

outspoken in his support for the use of civil nuclear energy<br />

as indeed he has for rejuvenating his country’s coal<br />

industry. However, proposals that paved the way for the US<br />

to offer incentives to power plants such as coal and nuclear<br />

in a bid to improve the resilience of the nation's power grid,<br />

were recently rejected by federal energy regulators.<br />

But Trump’s reason for backing nuclear does not appear<br />

to be linked to a desire to help the climate – or maybe it<br />

does – depending it seems on his temperament from one<br />

day to the next. You will recall that he pulled the US out of<br />

the Paris climate accord reached on his predecessor’s<br />

watch.<br />

But then a few weeks ago Trump said the US could<br />

go “go back” into the Paris deal. “We could conceivably go<br />

back in... I feel very strongly about the environment,” the<br />

president said during a joint news conference with<br />

Norwegian prime minister Erna Solberg.<br />

In a related move, Trump has demanded that European<br />

allies agree to rewriting a deal struck with Iran in 2015 –<br />

which lifted economic sanctions in exchange for Tehran<br />

limiting its nuclear ambitions beyond power generation –<br />

otherwise he said the US would pull out of the deal in the<br />

coming months, effectively “killing it”.<br />

The UK is also attempting a balancing act on matters<br />

nuclear. The government has confirmed Britain will exit<br />

Euratom at the same time as it withdraws from membership<br />

of the European Union on 29 March 2019.<br />

Greg Clark, secretary of state for business, energy and<br />

industrial strategy, told parliament the government’s<br />

“No.1 priority is continuity for the nuclear sector”. Clark<br />

said: “It is vitally important that our departure from the EU<br />

does not jeopardise this success, and it is in the interests of<br />

both the EU and the UK that our relationship should<br />

continue to be as close as possible.”<br />

Tom Greatrex, chief executive officer of the UK's Nuclear<br />

Industry Association, warned that even with a suitable<br />

transition being negotiated for Britain’s exit from the EU<br />

there “remains much work for the government to do<br />

to prevent the significant disruption that industry is<br />

concerned about.”<br />

Greatrex is of course correct. The UK has barely limped<br />

through the first phase of talks relating to Brexit and time<br />

is not on the side of either party. So for a minister to be<br />

talking about leaving Euratom – while at the same time<br />

continuing to enjoy the benefits that Euratom brings the<br />

UK – is surprising to say the least.<br />

Of course all these political machinations could be<br />

applied to any sector or policy and in any country. But the<br />

nuclear industry has long accepted that it can be used as a<br />

political football, to be kicked into goal or off the pitch<br />

completely depending on the situation at hand.<br />

I am reminded of a quotation from Otto von Bismarck,<br />

the ‘Iron Chancellor’, who said: “Politics is the art of the<br />

possible, the attainable – the art of the next best.”<br />

No political leader wants the lights going off and<br />

hurting homes, hospitals and businesses while they are in<br />

charge. They also don’t want to be seen as responsible for<br />

driving up unemployment.<br />

In terms of nuclear, whether cheerleaders for the<br />

technology or not, as the French president said: “You have<br />

to pick your battle.” The nuclear industry is all too familiar<br />

with fighting battles – defending itself from attack while<br />

quietly going about its task of safely supplying clean<br />

electricity to power-hungry grids around the world.<br />

Our industry therefore has power in the political sense<br />

too, but with power comes responsibility – nuclear leaders<br />

know that only too well and now is as good as time as ever<br />

to lead by example.<br />

Nuclear Today<br />

Playing Politics with Nuclear is All Part of the Game ı John Shepherd


Kommunikation und<br />

Training für Kerntechnik<br />

International sicher agieren<br />

Seminar:<br />

Advancing Your Nuclear English (Aufbaukurs)<br />

Im internationalen Dialog ist Englisch die universelle Sprache. Dies gilt für Geschäfts beziehungen<br />

im Allgemeinen ebenso wie für die Branche der Kerntechnik im Speziellen. In Deutschland gewinnen<br />

der internationale Austausch und damit das Englische zudem durch die auf das Jahr 2<strong>02</strong>2 politisch<br />

begrenzte Stromerzeugung aus Kernenergie eine noch größere Bedeutung.<br />

Seminarinhalte<br />

ı Participating in an international conference for nuclear experts on “New products and processes”<br />

ı Before and during the conference<br />

ı Holding a town hall meeting in an international setting on “Safety issues at nuclear power facilities”<br />

ı Planning and conducting a town hall meeting<br />

ı After a town hall meeting<br />

Den Teilnehmerinnen und Teilnehmern wird über eine praxisorientierte Didaktik und unter der<br />

Verwendung „kerntechnischen Vokabulars“ das notwendige Know-how für den beruflichen Alltag<br />

vermittelt. Dabei gilt es sprachlich bedingte Kommunikationsbarrieren mit internationalem Kollegium<br />

und Kunden zu überwinden.<br />

Zielgruppe<br />

Diese 2-tägige Schulung richtet sich an Führungskräfte, Projektverantwortliche sowie Mitarbeiterinnen<br />

und Mitarbeiter aus allen Fachbereichen, bei denen Englisch für die organisationsinterne und/oder<br />

externe Kommunikation von Bedeutung ist.<br />

Maximale Teilnehmerzahl: 12 Personen<br />

Voraussetzungen<br />

Teilnehmerinnen und Teilnehmer sollten grundsätzliche Englischkenntnisse, in Form der Fähigkeit<br />

der allgemeinen Konversation in Wort und Schrift, mitbringen. Hierbei kann es sich um Kenntnisse<br />

handeln, die entweder während der Schulzeit bzw. während der Ausbildung/des Studiums oder<br />

aber berufs begleitend erworben wurden. (CEFR: etwa Niveau B1/B2).<br />

Referentin<br />

Devika Kataja<br />

Konferenzdolmetscherin, Fachübersetzerin und Sprachtrainerin (English Native Speaker)<br />

Wir freuen uns auf Ihre Teilnahme!<br />

Termin<br />

2 Tage<br />

11. bis 12. April <strong>2018</strong><br />

Tag 1: 10:30 bis 17:30 Uhr<br />

Tag 2: 09:00 bis 16:30 Uhr<br />

Veranstaltungsort<br />

Geschäftsstelle der INFORUM<br />

Robert-Koch-Platz 4<br />

10115 Berlin<br />

Teilnahmegebühr<br />

898,– € ı zzgl. 19 % USt.<br />

Im Preis inbegriffen sind:<br />

ı Seminarunterlagen<br />

ı Teilnahmebescheinigung<br />

ı Pausenverpflegung<br />

inkl. Mittagessen<br />

Kontakt<br />

INFORUM<br />

Verlags- und Verwaltungsgesellschaft<br />

mbH<br />

Robert-Koch-Platz 4<br />

10115 Berlin<br />

Petra Dinter-Tumtzak<br />

Fon +49 30 498555-30<br />

Fax +49 30 498555-18<br />

seminare@kernenergie.de<br />

Bei Fragen zur Anmeldung<br />

rufen Sie uns bitte an oder<br />

senden uns eine E-Mail.


The International Expert Conference on Nuclear Technology<br />

Outstanding Know-How<br />

and Innovations<br />

Insights<br />

on AMNT<br />

Watch the video:<br />

http://youtu.be/<br />

DDC3L3XhnoA<br />

The AMNT <strong>2018</strong> offers a great variety of high level sessions in the fields<br />

of know-how, innovations and regulation. International speakers<br />

will discuss current issues and relevant developments. Expand your<br />

professional network in meetings with experts and decision-makers<br />

working in industry, utilities, research and development as well as<br />

politics and administration.<br />

Sessions<br />

3 International Regulation – Radiation Protection:<br />

The Implementation of the EU Basic Safety Standards Directive 2013/59<br />

and the Release of Radioactive Material from Regulatory Control<br />

3 Safety of Advanced Nuclear Power Plants<br />

3 Know-How, New Build and Innovations<br />

3 Reactor Physics, Thermo and Fluid Dynamics<br />

3 Young Scientists’ Workshop<br />

3 Nuclear Energy Campus<br />

Outstanding<br />

Know-How &<br />

Sustainable<br />

Innovations<br />

Enhanced<br />

Safety &<br />

Operation<br />

Excellence<br />

Decommissioning<br />

Experience &<br />

Waste Management<br />

Solutions<br />

Don’t miss this key event of the global nuclear energy community.<br />

29 – 30 May <strong>2018</strong><br />

Estrel Convention Center Berlin<br />

Germany<br />

www.nucleartech-meeting.com

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