Nuclear Safety
NEA/CSNI/R(2019)9
May 2019
www.oecd-nea.org

Proceedings of the Nuclear

Energy Agency International
Workshop on Chemical Hazards
in Fuel Cycle Facilities Nuclear
Processing

Nuclear Energy Agency

NEA/CSNI/R(2019)9
Unclassified

English text only
12 June 2019

NUCLEAR ENERGY AGENCYCOMMITTEE ON THE SAFETY OF NUCLEAR INSTALLATIONS

Proceedings of the Nuclear Energy Agency International Workshop on Chemical
Hazards in Fuel Cycle Facilities Nuclear Processing

Boulogne-Billancourt, France, 17-19 April 2018.

JT03448750

This document, as well as any data and map included herein, are without prejudice to the status of or sovereignty over any territory, to thedelimitation of international frontiers and boundaries and to the name of any territory, city or area.

2 │ NEA/CSNI/R(2019)9
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NUCLEAR ENERGY AGENCYThe OECD Nuclear Energy Agency (NEA) was established on 1 February 1958. Current NEA membership consistsof 33 countries: Argentina, Australia, Austria, Belgium, Canada, the Czech Republic, Denmark, Finland, France,
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Specific areas of competence of the NEA include the safety and regulation of nuclear activities, radioactive waste
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NEA/CSNI/R(2019)9│3

Committee on the Safety of Nuclear Installations
The Committee on the Safety of Nuclear Installations (CSNI) is responsible for the Nuclear Energy Agency(NEA) programmes and activities that support maintaining and advancing the scientific and technicalknowledge base of the safety of nuclear installations.
The Committee constitutes a forum for the exchange of technical information and for collaboration
between organisations, which can contribute, from their respective backgrounds in research, development
and engineering, to its activities. It has regard to the exchange of information between member countries
and safety R&D programmes of various sizes in order to keep all member countries involved in and abreastof developments in technical safety matters.
The Committee reviews the state of knowledge on important topics of nuclear safety science andtechniques and of safety assessments, and ensures that operating experience is appropriately accounted forin its activities. It initiates and conducts programmes identified by these reviews and assessments in order
to confirm safety, overcome discrepancies, develop improvements and reach consensus on technical issuesof common interest. It promotes the co-ordination of work in different member countries that serve tomaintain and enhance competence in nuclear safety matters, including the establishment of joint
undertakings (e.g. joint research and data projects), and assists in the feedback of the results to participatingorganisations. The Committee ensures that valuable end-products of the technical reviews and analyses areprovided to members in a timely manner, and made publicly available when appropriate, to support broader
nuclear safety.
The Committee focuses primarily on the safety aspects of existing power reactors, other nuclear
installations and new power reactors; it also considers the safety implications of scientific and technicaldevelopments of future reactor technologies and designs. Further, the scope for the Committee includes
human and organisational research activities and technical developments that affect nuclear safety.

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Acknowledgements
Gratitude is expressed to the Workshop Organising Committee, the Session Chairpersons
and the workshop participants for their efforts and co-operation.

Workshop Organising Committee
Name

Organisation, country

Véronique Lhomme
Marc Philippe
Craig Erlanger
Marilyn Diaz-Maldonado
Kenji Mori
Mitsuhiro Takanashi
Sarah Eaton
Olli Nevander

IRSN, France
IRSN, France
NRC, United States
NRC, United States
S/NRA/R, Japan
S/NRA/R, Japan
CNSC, Canada
NEA, International

Session Chairpersons
M. Diaz-Maldonado, US NRC
S. Eaton, CNSC
V. Lhomme, IRSN
C. Erlanger, US NRC
M. Takanashi, S/NRA/R
O. Nevander, NEA

NEA/CSNI/R(2019)9│5

Table of contents
Executive summary ............................................................................................................................... 6
List of abbreviations and acronyms ..................................................................................................... 8
1. Introduction ....................................................................................................................................... 9
2. Previous workshops ......................................................................................................................... 10
Toronto workshop in September 2011 ........................................................................................ 10
Aomori workshop in November 2016 ........................................................................................ 10
3. Workshop sessions and technical visit ........................................................................................... 11
Opening – Introduction and objectives of the workshop ............................................................ 11
Session 1: Regulations, standards, requirements and guidance for chemical safety
for FCFs ...................................................................................................................................... 11
Session 2: Consideration of chemical hazards for the design, commissioning, operationand decommissioning of FCFs .................................................................................................... 11
Session 3: Emergency preparedness and response in case of accidental situation due tochemical hazards in FCFs ........................................................................................................... 12
Session 4: Operating experience feedback on managing chemical hazards in FCFs.................. 13
Final panel discussions on sessions ............................................................................................ 13
Technical visit to Saclay site....................................................................................................... 14
4. Conclusion and recommendations ................................................................................................. 15
5. References ........................................................................................................................................ 17
Appendix A - List of participants....................................................................................................... 18
Appendix B - Technical programme of the workshop ..................................................................... 20
Appendix C - Conference papers ....................................................................................................... 22

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Executive summary
Chemical hazards are an important subject for Fuel Cycle facilities, including various
chemical processes and substances such as explosions and healthy risks.
On 17-18 April 2018, the Nuclear Energy Agency (NEA) Committee on the Safety of
Nuclear Installations (CSNI) Working Group on Fuel Cycle Safety (WGFCS) held theInternational Workshop on Chemical Hazards in Fuel Cycle Facilities Nuclear Processing
at the NEA offices in Boulogne-Billancourt, France. During the workshop, a total of
14 presentations were given in 4 sessions. Within the framework of this workshop, atechnical visit to the Atomic Energy Commission’s (CEA’s) Saclay Nuclear ResearchCentre, which is 20 kilometres from Paris, was organised on Thursday 19 April.
The Boulogne workshop focused on methods to ensure that fuel cycle facilities (FCFs) aredesigned and operated in a manner that prevents or mitigates the risks of hazardous
chemical exposure, corrosion, fire, explosion and contamination. Many of the safety
principles related to ensuring chemical safety under discussion during the Boulogne
workshop were already agreed in previous workshops in Toronto, Canada in 2011 and in
Aomori, Japan in 2016.
During the Boulogne workshop, it was noted that several FCFs have different chemicalhazard categorisations under relevant legislation, requiring more detailed assessments ofsafety. FCFs are using modern methods and tools for quantifying chemical hazards, fromthe Quantitative Risk Assessment (QRA) to detailed calculation codes, e.g. computational
fluid dynamics (CFD). It was agreed at the Boulogne workshop that a wide variety ofchemical hazards, associated with nuclear fuel processing and different from the hazards
in NPPs, should be taken into account in the design, construction, operation anddecommissioning of FCFs. The workshop concluded that the following issues are importantin the provision of safety measures and in the assessment of chemical risks:•Radiological and chemical releases from the facilities situated on the same siteshould be taken into account in the emergency procedures of FCFs.

•

FCFs should have precise detection systems, suitable protection devices andadequate operation and emergency procedures for all chemical and radioactive
leakages.

•

FCFs should have an effective process for assessing the lessons learnt on operating
experiences of events involving chemicals (releases of chemicals, explosions, toxic
fires, etc.). The process for assessing lessons learnt of chemical release events ofother FCFs could be arranged by adequate participation in the FINAS database. In
addition to recognising necessary design and operation modifications, this process– useful for identifying R&D needs in support of safety assessments sufficiently inadvance – is also crucial (“longer-term anticipation”).

•

Co-operation between various national regulatory organisations is necessary toensure the use of a graded approach to safety in the preparation of safety measuresagainst the various chemical hazards in FCFs.

NEA/CSNI/R(2019)9

During the panel and discussions, the following questions arose, related to sharing theoperational experiences of FCFs:•

Is there a need for comparison of procedures and methods for FCFs with theequivalent methods in use for NPPs? Can insights from the FINAS database be
used in this work?

•

Operating experience shows that problems in the modification process are very
often leading to and causing the events. This raises the question: Is the use of the
FINAS database adequate guided for the collection of events related to chemicalhazards? Is there a need to improve the use of the FINAS database and even use
other sources of information (e.g. chemical event databases) in the assessment ofchemical hazards in the modification and design processes of FCFs? Necessary
improvements to the FINAS database can be discussed during meetings of the
CSNI Working Group on Fuel Cycle Facilities (WGFCS) in the near future.

•

Is there a need for work to compare qualitative and quantitative assessment(e.g. assessment on probability of events and their consequences) for chemicalhazards? Is there a need to compare exposure standards used in the nuclear industry
as well as in the chemical industry?

The questions above could be among the key subjects for international workshops of FCFs
arranged by the WGFCS and the International Atomic Energy Agency in the near future.

│78 │ NEA/CSNI/R(2019)9

List of abbreviations and acronyms
AEGL
ASN
CEA
CFD
CNSC
CSN
CSNI
EDF
EOPs
FCF
FINAS
HLLW
IAEA
IRSN
NEA
NPP
NRA
NRC
OECD
QRA
SNF
S/NRA/R
WGFCS

Acute exposure guideline levels (for airborne chemicals)
Autorité de Sûreté Nucléaire (France)
Commissariat à l'énergie atomique et aux énergies alternatives (France)
Computational fluid dynamics
Canadian Nuclear Safety Commission
Consejo de Seguridad Nuclear (Spain)
Committee on the Safety of Nuclear Installations (NEA)
Électricité de France
Emergency operating procedures
Fuel cycle facility
Fuel Incident Notification and Analysis System
High- and low-level waste
International Atomic Energy Agency
Institut de radioprotection et de sûreté nucléaire (France)
Nuclear Energy Agency
Nuclear power plant
Nuclear Regulation Authority (Japan)
Nuclear Regulatory Commission (United States)
Organisation for Economic Co-operation and Development
Quantitative risk assessment
Spent nuclear fuelRegulatory Standard and Research Department, Secretariat of Nuclear Regulation Authority(Japan)Working Group on Fuel Cycle Safety (NEA CSNI)NEA/CSNI/R(2019)9

1. Introduction
This is a summary report for the Nuclear Energy Agency (NEA) Committee on the Safetyof Nuclear Installations (CSNI) Working Group on Fuel Cycle Safety (WGFCS)International Workshop on Chemical Hazards in Fuel Cycle Facilities Nuclear Processing
held in Boulogne-Billancourt, France, on 17-19 April 2018. It describes the presentationsin the workshop and conclusions drawn during the discussions and closing panel. During
the workshop, a total of 14 presentations were given to 31 participants in 4 technicalsessions:•

regulations, standards, requirements and guidance for chemical safety for FCFs;•

consideration of chemical hazards for the design, commissioning, operation anddecommissioning of FCFs;•

emergency preparedness and response in case of accidental situations due tochemical hazards in FCFs;•

operating experience feedback on managing chemical hazards in FCFs.

The discussions on chemical hazards were based on work done in two previous workshopsof the WGFCS, namely, the Toronto, Canada workshop in September 2011 and theworkshop in Aomori, Japan in November 2016.
The main objective of this workshop was to bring together specialists involved in FCF
safety in order to discuss chemical hazards associated with nuclear fuel processing. The
objectives of the workshop were to review national activities, safety and regulatory
approaches for managing chemical hazards at FCFs, the effectiveness of these activities,
and areas for improvement. The scope of FCFs covered included uranium conversion
facilities, uranium enrichment facilities, all types of fuel fabrication facilities, irradiatedmaterial processing facilities and waste management operations.
FCFs employ many diverse technologies with large variations in physical and chemical
forms of the processed materials. These imply a wide variety of chemical hazards, different
from the hazards in NPPs, which are to be taken into account in design, construction,
operation and decommissioning of FCFs.
The hazardous chemical substances used in the production processes may be toxic,
corrosive, combustible, reactive or explosive, and disturbances may lead to specificchemical releases and personnel exposures.
These chemical, personnel and industrial hazards and their consequences need extra careand the conventional occupational safety and health requirements related to these hazards
must be taken into consideration by utilities and regulators, when looking at the generalsafety of FCFs.

│910 │ NEA/CSNI/R(2019)9

2. Previous workshops
Toronto workshop in September 2011
In Toronto, Canada, on 27-29 September 2011, the workshop on “Safety Assessment ofFuel Cycle Facilities – Regulatory Approaches and Industry Perspectives” (NEA, 2013)
drew several broad conclusions related to chemical hazards as follows:•

Participants recognised the importance of the impact of chemical hazards on safetyassessment of fuel cycle facilities (FCFs) in addition to radiation hazards, especiallywhen we are trying to keep good reputation and safety records of the nuclear
industry.

•

Participants felt that there is a need for improved co-ordination between various
regulatory bodies within each country, especially in the area of chemical hazards.
It may be beneficial to benchmark with other facility types within the nuclear
industries (such as NPPs) as well as outside (such as the petrochemical industry) toidentify cross-learning opportunities in managing various types of chemicals.

In the Toronto workshop (NEA, 2013) it was noted that the IAEA mandate does not include
chemical hazards, unless it leads to radiation hazards. Therefore, it is even more importantthat the CSNI WGFCS should continue to support technical workshops in the area on
chemical hazards. It was also noted in the Toronto workshop that there is a need for aninternational reference library of chemical hazards related to FCFs.

Aomori workshop in November 2016
FCFs have a large variety of physical and chemical forms of processed materials, andtherefore many of the actions presented at the NEA Workshop on Developments in Fuel
Cycle Facilities after the Fukushima Daiichi Nuclear Power Station Accident (or Aomori
workshop) were suitable only for specific facilities. The Aomori workshop in 2016 (NEA,
2018) pointed out new requirements, good practices and new research on chemical hazards,
and applications of these with a graded approach for FCFs. Applications of a gradedapproach will be used for FCFs in assessing the requirements and methods to mitigate theeffects of exposure of the various chemical substances and their combinations toradioactive substances during accidents.
Furthermore, it was noted in the Aomori workshop (NEA, 2018) that differences in national
legislation and regulatory approaches do not change the responsibility of FCF operators toprovide a full assessment of chemical hazards including the combination of these hazards
with nuclear and radiological risks. This means that all chemical forms and concentrationsof radioactive and toxic substances, major physical processes and exposure pathways andtheir consequences are identified and analysed in a comprehensive safety case for FCF.

NEA/CSNI/R(2019)9

3. Workshop sessions and technical visit
Opening – Introduction and objectives of the workshop
The opening session was chaired by Mr Takanashi (S/NRA/R) and Mr Erlanger (US NRC).
In the opening session, Mr Nevander from the Nuclear Energy Agency (NEA) gave a shortoverview on the NEA objectives and goals for the workshop. Next, Mr Bodenez, theDeputy Head of the Technical Risks Department in the Ministry of Ecological andSolidarity Transition of the French Government highlighted examples of industrial
accidents throughout the world and made a statement on the legal framework on theprevention of chemical accidents in Europe as well as an overview of the international
co-operation frameworks.

Session 1: Regulations, standards, requirements and guidance for chemicalsafety for FCFs
Session 1 was chaired by Ms Diaz-Maldonado of the US NRC, and there were fivepresentations on the regulations, standards, requirements and guidance used in member
countries. These presentations gave insights on the different regulatory approaches used toregulate chemical hazards, especially in the Canada, France, Japan and the United States.
A discussion took place on the need to develop a best practices document that highlights
the different regulatory approaches of participating countries/organisations.
The radiological and associated chemical or toxicological releases to the environment arecollectively termed the ‘environmental impact’ of the fuel cycle facility (FCF). It was notedthat ensuring the function of confinement and control for radioactive material in FCF canbe dependent on the effective management of various chemical reactions. The rapid
progression and limited grace period of some scenarios leading to toxicologicalconsequences or contamination by soluble radioactive material is a specific feature ofcertain types of FCFs. Regulations and standards require that associated chemical andindustrial hazards shall be analysed and taken into account in deriving appropriate design
criteria and identifying preventive or mitigative controls for the FCFs.
It was also recognised that there are different risk practices used by organisations inparticipating countries. All appear to be effective. During Session 1, a need was identified
for more a detailed safety assessment and evaluation of qualitative vs quantitative safety
analyses. More discussion addressing these types of analyses is necessary. The discussions
and different presentations showed that only very few countries have some prescriptive
criteria or exposure limits stated in their national regulations. The chemical exposure limits
vary and are chosen according to the studied situations and parameters. Further
understanding of the basis of exposure limits used by participating countries/organisations
is needed.

Session 2: Consideration of chemical hazards for the design, commissioning,
operation and decommissioning of FCFs
The second session was chaired by Ms Eaton of the Canadian Nuclear Safety Commission(CNSC) and included two presentations:│ 1112 │ NEA/CSNI/R(2019)9
The first one concerned the development of a methodology relating to the identification
and assessment of reactive chemical hazards of sorption systems in spent nuclear
fuel (SNF) reprocessing plants, including modelling of the chemical reactions involved that
could lead to explosion risks and potential radiological consequences for the workers, thepublic and the environment.
The second one pointed out the understanding of radiolytic mechanisms and otherparameters, which influence the material under normal and accidental/extreme conditions.
The modelling contributions (e.g. multi-scale modelling, fast free radical reactions,reactivity, and speciation) were recognised as requiring backup from experimental
qualification and test results.
During the discussion it was noted that the analysing and updating of possible chemicalhazards is an important part of the safety assessment, including/especially whenmodifications and upgrades are made to the processes. The categorisation of modifications
and the building of clear administrative paths to get problems and deviations recognised
during modification into processing are important parts of the management system of FCFs.
Good procedures for the administration of modifications are important and need to be clear,
including systems for categorising modifications, resolving problems and for identifying
deviations. It was agreed that it is important to prevent events relating to chemical processmodifications with applicable requirements, internal and external reviews of FCFs andlessons learnt on reported chemical events.

Session 3: Emergency preparedness and response in case of accidental situation
due to chemical hazards in FCFs
The third session was chaired by Ms Lhomme, of the French Radioprotection and Nuclear
Safety Institute (IRSN) and two presentations on accident management measures were
provided in this session.
The presentation given by the IRSN described a new R&D programme to re-examine theHigh and Low Level Waste (HLLW) storage tanks loss-of-coolant accident to improveknowledge of ruthenium behaviour during the accident phases from evaporation up to
dryness and associated risk control measures.
Then, a representative from Sellafield Ltd presented the grab cards produced by the
Emergency Management Technical Team at Sellafield Ltd for chemical hazards in order toprovide timely and technically underpinned advice for the responders to be able to protect
the workforce and public, whilst minimising environmental consequences and aid inrecovery.
In this session, the use of the emergency response handbook and procedures for generalguidance of actions and use of computer modelling for predicting the routes of plumes ofchemical releases was discussed. It was noted that the online modelling of routes of plumes
is not widely used in FCFs. It was also noted that chemical events cause damage to healthand the environment in a much shorter timescale (it takes only some seconds to harm aperson) compared to the radioactivity accidents.
The annual emergency exercises and prepared and analysed action lists for accidents inprocedures of FCFs were recognised to be effective tools for such situations. It was agreed
that comprehensive, dedicated detection and monitoring equipment for various chemical
releases was necessary for various emergency situations to initiate the countermeasures.

NEA/CSNI/R(2019)9

Session 4: Operating experience feedback on managing chemical hazards in
FCFs
The fourth session was chaired by Mr Erlanger of the US NRC and there were four
presentations on using operating experience feedback in member countries for the WGFCS
provided in this session.
FINAS can be utilised to provide illustrative examples, trending on events involving
chemical hazards and to develop lessons learnt to be shared with all the participating
countries. Participating countries/organisations, based on operating experience, have aneed for research in particular areas related to chemical hazards in FCFs, e.g. red oil
explosions and limits to control or prevent accidents.
During Session 4, the different practices used by participating countries to regulate or
manage chemical hazards were discussed. There seems to be a need to develop a high level
best practices document that highlights areas to be mindful of when managing chemicalhazards.
The following aspects were recognised as conclusions of the fourth session:•

Several FCFs fall within high chemical hazard categories, requiring more detailed
assessments of safety.

•

FCFs are using modern methods and tools for quantifying chemical hazards, from
Quantitative Risk Assessment (QRA) to detailed computational fluid dynamics(CFD). However, the symptom and state based models and procedure development
methodologies used in NPPs could be applied to the emergency operatingprocedures and emergency plans for chemical hazards of FCFs.

•

Acute Exposure Guideline Levels for Airborne Chemicals (AEGL) for harmful
chemicals are necessary to be used as a basis for design against of chemical hazards.

Final panel discussion on sessions
The panel discussion was chaired by M. Takanashi (NRA) and O. Nevander (OECD/NEA)
and the four panellists were M. Philippe (IRSN), R. Gater (IAEA), W. Kwan (SellafieldLtd) and C. Erlanger (US NRC).
The final panel discussion confirmed many of the subjects recognised during the workshop
sessions. It was agreed that the workshop presentations pointed out some difficult topics
relating to chemical safety, such as the chemistry that leads to releases of hydrogen andruthenium. These are problems of complexity, meaning that they are problems in FCF
operation because they are so complex. For example, hydrogen is produced by corrosion
as well as radiolysis. Some of the radiolysis reactions that produce hydrogen are reversible;
almost all corrosion phenomena are irreversible. Technically, hydrogen gas can expand tooccupy all of the volume available to it. It may be better to restrict it to as small a volume
as possible, and keep flushing it away. Therefore, there is need for more knowledge abouthydrogen production processes and more knowledge on means for hydrogen removal
without negative impacts in other areas.
Furthermore, the importance of R&D in support of safety assessments has beenremembered. Indeed, it is crucial to identify R&D needs sufficiently in advance (“longerterm anticipation”), taking into account the feedback from previous safety assessments(gaps to be identified), the operating experience from FCFs including chemical hazards,│ 13

14 │ NEA/CSNI/R(2019)9
the expected future evolutions of the process or facilities and technology and scientificmonitoring. Actually, it is also important to periodically identify main topics for whichstate-of-the-art or knowledge syntheses would be necessary to identify new research needs.
Modelling in the field of the evaluation of chemical risks (i.e. thermal stability ofchemicals, thermal runaway reactions, etc.) was also stressed. Nevertheless, this approachrequires a full understanding of the phenomenology and reaction mechanism. In addition,
the importance of knowing the effect of irradiation on solutions or materials with regard to
the chemical hazards and not to content oneself on testing simulants was emphasised.
Finally, a thorough evaluation of chemical hazards associated with the decommissioning
activities is also necessary because the different processes used for cleaning use newchemicals and reagents which may lead to new risks.
It was also noted that these types of difficult technological problems require the sharing ofexpertise and ideas between many people of different subject disciplines; such as chemists,
physicists and engineers in different fields. This kind of work requires an effective
management system with internal prioritising of tasks with coherent principles and in thesame order and schedule in all disciplines. The existing national regulations and standards
may not help operators or different regulators of chemicals and radioactivity to co-operate,
but this co-operation is necessary for effective actions. It is obvious that information
available for minimising the risks should be shared between facilities with similar risks.
Furthermore, facilities could pool their data and their effort in the interests of safety. This
could be done in spite of the competition between operators and research organisations,especially, when co-operative work between FCFs could be arranged through internationalorganisations such as the NEA and the IAEA.

Technical visit to Saclay site
The workshop ended on 19 April, with a visit to Saclay laboratories near Paris, France.
Saclay is the largest CEA site, in terms of numbers of people in France. Having a long
history, it has one research reactor, a new medical facility called Neurospin, several
accelerators plus several laboratories operated by the IRSN. The group visited the IRSN’s
experimental facilities and means and especially TOSQUAN, which is used to reproduce
thermohydraulic conditions simulating accident scenarios that may occur in a containment
vessel and to assess the effect of mitigation measures, such as the internal spray system inthe containment vessel. Also test facility STARMANIA, which is intended for studying theaeraulic and mechanical behaviour of compartmentalisation and containment equipment,
subjected to pressure and temperature in nuclear facilities (fire, rupture of steam pipes,
post-earthquake conditions, etc.) was visited. The group also visited some of the CEA’s
laboratories from the Nuclear Activities Direction of Saclay/Physico-Chemistry
Department.

NEA/CSNI/R(2019)9

4. Conclusion and recommendations
The Nuclear Energy Agency (NEA) International Workshop on Chemical Hazards in Fuel
Cycle Facilities Nuclear Processing, held in Boulogne in 2018 was organised by theCommittee on the Safety of Nuclear Installations (CSNI) Working Group on Fuel Cycle
Safety (WGFCS). Workshop focused on methods to ensure that fuel cycle facilities (FCFs)
are designed and operated in a manner that controls and minimises the risks of hazardous
chemical exposure, corrosion, fire, explosion and contamination associated with nuclear
fuel processing.
In previous workshops in Toronto, Canada in 2011 and in Aomori, Japan in 2016, it was
already noted that all chemical forms and concentrations of radioactive and toxic
substances, major physical processes and exposure pathways and their consequences need
to be identified and assessed in a comprehensive safety case of the FCF. Furthermore, it
was agreed that these analyses on estimated source terms of radiological and chemical
releases to the environment and their trajectories make the measures described in theemergency operating procedures (EOPs) more effective.
During the Boulogne workshop and its discussions, it was noted that several FCFs fallwithin high chemical hazard categories, and thus require more detailed assessments ofsafety. FCFs are using modern methods and tools for quantifying chemical hazards, fromquantitative risk assessment (QRA) to detailed calculation codes, e.g. computational fluid
dynamics (CFD). Some are freely available, but adequate validation data may be missing
for some of these codes. Calculation codes and models for releases to the atmosphereinclude a great deal of uncertainties. It was recognised that acute exposure guideline levels(AEGLs) are now used by some operators for quantifying emergency exposure criteria
from chemical accidents.
It was agreed in the Boulogne workshop that a wide variety of chemical hazards (different
from the possible hazards in NPPs), should be taken into account in the design,
construction, operation and decommissioning of FCFs. The workshop concluded that thefollowing issues are important in the preparation of safety actions and in the assessment of
the risk of the chemical hazards:•

Radiological and chemical releases from the facilities situated at the same siteshould be taken into account in the emergency procedures.

•

FCFs should have precise detection measurements, suitable protection devices andadequate operation and emergency procedures for all radioactive leaks andassociated chemical releases.

•

FCFs should have an effective process for assessing the lessons learnt on operating
experiences of chemical release events. The process for assessing lessons learnt forchemical release events of other FCFs could be arranged through adequate
contribution to the FINAS database. In addition to recognising necessary designand operation modifications, this process is useful for identifying R&D needs insupport of safety assessments sufficiently in advance (“longer-term anticipation”).

•

Co-operation between various national regulatory organisations is necessary toensure a graded approach to safety in the protection from the various chemicalhazards of FCFs.

│ 15

16 │ NEA/CSNI/R(2019)9
During the panel and discussions of the workshop the following questions related to sharing
operational experiences of FCFs were noted:•

Is there a need for comparison of procedures and methods for FCFs with theequivalent methods in use for NPPs? Can insights from the FINAS database be
used in this work?

•

Operating experience shows that problems in the modification process are very
often leading to and causing the events. This raises the question: Is the use of the
FINAS database adequate guidance for chemical hazards? Is there a need to
improve the use of the FINAS database in the assessment of chemical hazards inthe modification and design processes of FCFs?

•

Is there a need for work to compare qualitative and quantitative assessment(e.g. assessment on probability of events and their consequences)? Is there a needto compare exposure standards used in the nuclear industry as well as in thechemical industry?

It was agreed in the Boulogne workshop that the reasonable application of sophisticatedsafety procedures and resource-demanding assessment methods of NPPs for large
variations of FCFs will be one of the key challenges at the international level in the future.
The use of a graded approach together with lessons learnt in terms of events in the FINAS
database could be one of answer for these challenges.

NEA/CSNI/R(2019)9

5. References
NEA (2013), “Safety Assessment of Fuel Cycle Facilities – Regulatory Approaches andIndustry Perspectives”, Proceedings from the NEA CSNI Workshop held in Toronto,
Canada on 27-29 September 2011; NEA/CSNI/R(2012)4, OECD, Paris.
NEA (2018), “Developments in Fuel Cycle Facilities after the Fukushima Daiichi Nuclear
Power Station Accident”, Proceedings from the NEA CSNI Workshop held in Aomori City,
Japan on 15-17 November 2016; NEA/CSNI/R(2017)12, OECD, Paris.

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Appendix A - List of participantsFirst name

Organisationor company

BECKERGaëtanOrano

BODENEZ

Philippe

Ministry of Sustainable Development

BOURROUS

Soleiman

IRSN

BULIT

Jean-MarcIRSN

CANTREL

LaurentIRSN

CARLVIK

NicklasWestinghouse Electric Sweden AB

DE ALMEIDA

Lucie

IRSN

DELIME

Brice

ASN

DIAZ
MALDONADO

Marilyn

US NRC

DUMAS

Agnès

IRSN

EATON

Sarah JaneCNSC

ERLANGERCraig

US NRC

GATER

Ramon

IAEA

Family name

NEA/CSNI/R(2019)9First name

Organisationor company

GUILLARD

MichelIRSN

HEMIMOU

YoucefASN

KWAN

WilliamSellafield Ltd

LHOMME

Véronique

IRSN

LOSINGER

Mathieu

Orano

MOISAN

LionelOrano

MONFORT

Marguerite

CEA

MORI

Kenji

S/NRA/R

MULYE

Hemendra

CNSC

NERISSONPhilippe

IRSN

NEVANDER

Olli Vilhelm

OECD/NEAORTEGARICOAngelica

IRSN

PHILIPPE

Marc

IRSN

PLUNTZ

Laurène

IRSN

RODIN

AlexeySECNRSROUXSERRET

Véronique

Orano

TAKANASHI

Mitsuhiro

S/NRA/R

YAMAGUCHI

Akinori

S/NRA/R

Family name│ 19

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Appendix B - Technical programme of the workshop
17 April 2018 - NEA building, room BB1
9:30 – 10:30
Opening Session - Chairpersons: M. Takanashi (S/NRA/R), C. Erlanger (USNRC)NEA objectives and goals for the workshop - O. Nevander (NEA)
Prevention of risks in chemical facilities in France - P. Bodenez (Head of Department ofaccidental hazards, General Directorate of prevention of risks, Ministry of Ecological andsolidarity-based Transition)
Practical arrangements of the workshop – O. Nevander (NEA)
10:50 – 13:00
Session 1: Regulations, standards, requirements and guidance for chemical safety for
FCF’s, Chair: M. Diaz-Maldonado, US/NRC(5) Chemical Hazards and the IAEA Safety Standards, R. Gater (IAEA)(8) French framework regulation related to chemical hazards in nuclear Fuel Cycle
Facilities, B. Delime (ASN) and Y. Hemimou (ASN)(15) Chemical Safety Requirements in the United States For Commercial Fuel Cycle
Facilities, M. Diaz-Maldonado (US NRC) (1) Chemical Effects and their Evaluation Methods for Accidental Release of Uranium
Hexafluoride, K. Mori (S/NRA/R)(9) Assessment of Risks to Human Health and the Environment of Hazardous Substancesin Nuclear Fuel Cycle Facilities in Canada, H. Mulye (CNSC)
14:15 – 15:15
Session 2: Consideration of chemical hazards for the design, commissioning, operation anddecommissioning of FCFs, Chair: S. Eaton, Canada, CNSC
(6) Estimation of reactive chemical hazards of sorption systems for reprocessing SNF, A.
Rodin (SEC NRS)
(13) Radiolysis and safety concerns in nuclear fuel cycle, M. Philippe (IRSN)
15:40-16:40
Session 3: Emergency preparedness and response in case of accidental situation due tochemical hazards in FCFs, Chair: V. Lhomme, France, IRSN
(2) R&D programme on volatilisation and transport behaviour of ruthenium under a loss ofcooling accident on high level liquid waste (HLLW) storage tanks in reprocessing plants
and mitigation strategies, Ph. Nérisson (IRSN)(12) Grab cards for chemical hazards at Sellafield Ltd, W. Kwan (Sellafield Ltd)
16:40 – 17:30
Session 4: Operating experience feedback on managing chemical hazards in FCFs, Chair:
C. Erlanger, US NRC

NEA/CSNI/R(2019)9(3) Reassessment of explosion risks associated with red oils in French reprocessing plants
and related R&D and first results, A. Ortega Rico (IRSN)(4) Reassessment of chemical hazards for the first periodic safety reviews of AREVA NC
La Hague reprocessing plants – the corrosion ageing of FP evaporators’ case, L. Almeida(IRSN)
17:30 - 17:50
Closing Discussion of first day
18 April 2018 NEA building, room BB1
10:00 – 11:00
Session 4: Operating experience feedback on managing chemical hazards in FCFs, Chair:
C. Erlanger, US NRC(10) The Operating Experience Feedback of Chemical Hazards in Canada, S. Eaton(CNSC)(14) Comparison of U.S. Operating Experience from Nuclear Fuel Cycle Facilities andCommercial Industrial Plants, C. Erlanger (US NRC)
11:10 – 12:00
FINAL PANEL DISCUSSIONS - Chairs: M. Takanashi, O. Nevander
Panel:
M. Philippe
R. GaterW. KwanC. Erlanger│ 2122 │ NEA/CSNI/R(2019)9

Appendix C - Conference papers
The Papers (Appendix C) presented during the workshop can be found on the NEA website.