Safety Cases for the Deep Disposal of Radioactive Waste: Where Do We Stand?
23-25 January 2007
Disposal of long-lived radioactive waste in engineered facilities, or repositories, located deep underground in suitable geological formations, is being investigated world wide as a means to protect humans and the environment both now and in the future. The modern concept of the safety case for deep disposal was developed in the 1990s and first presented in the NEA document Confidence in the Long-term Safety of Deep Geological Repositories: Its Development and Communication.
Recently, there has been notable convergence in documents published nationally and internationally on the understanding and development of long-term safety cases for deep disposal. The NEA brochure Post-closure Safety Case for Geological Repositories (2004) defines and discusses the purpose and general contents of such studies. Similar concepts are presented in the IAEA Safety Requirement on Geological Disposal of Radioactive Waste (WS-R-4), co-sponsored by NEA. Following these developments, and more than 15 years after the OECD international symposium of 1989, it was appropriate to take stock of progress.
- The symposium focused on the safety case for deep disposal facilities. Safety cases in other fields are of interest only for comparison.
- The symposium covered practical experience in addressing the development of the several elements that constitute a safety case.
- Presentations including various stakeholders, also addressed how to communicate and present a safety case.
The aims of the symposium were:
- to share practical experiences on preparing for, developing, and documenting a safety case both at the technical and managerial level (test the concept of a safety case);
- to share experiences on the regulatory perspective. What are the regulatory requirements and expectations of the safety case? Does the safety case provide answers?
- to highlight the progress made in the last decade; the actual state of the art and the observed trends;
- to assess the relevance of the international contributions in this field;
- to receive indications useful to the future working programme of the NEA and other international organizations.
- Session I provided a comprehensive overview of recent progress regarding the safety case concept in the national programme for our host country, France.
- Session II provided an overview of the international evolution of the safety case concept. It describes the progression of international guidance on the topic, and provides key examples of implementation of these concepts in various national programmes. A panel discussion will explore these issues in depth.
- Session III highlighted recent practical experiences in developing, supporting, and reviewing safety cases, including views of regulatory agencies and decision-makers.
- Session IV addressed the role of the safety case in societal dialogue, and focuses on communication aspects with the emphasis on non-institutional actors.
- A poster session was organised to present additional papers on relevant topics during the second day of the symposium.
Day 1 - 23 January 2007
Opening – Welcome addresses
OECD Nuclear Energy Agency
French Ministry of Research
Director, Department of Energy, Transport, Environment, and Natural Resources
International Atomic Energy Agency
Director of Radiation, Transport and Waste Safety
Head of Unit "Fission", DG-Research
Session I: French National Programme on Deep Disposal Safety
Chair: H. Riotte (NEA)
Rapporteur: A. Hooper (Nirex)
Session II: The Safety Case Concept and its Evolution
Chair: C. Ruiz Lopez (CSN)
Rapporteur: P. de Preter (ONDRAF/NIRAS)
Session II-a: The International Evolution
Questions and Answers
Session II-b: The National Evolution
Questions and Answers
Session II-c: Plenary Panel Discussion
Moderators: M. Sailer (Oeko Institut) and C. McCombie (Arius)
Rapporteur: R. Ferch (Consultant, Canada)
The aim was to give the floor to the audience: opinion, discussion, open questions. The moderators gave a short summary and set forth questions for discussion.
Day 2 - 24 January 2007
Session III: Recent Experiences in Developing a Safety Case
Session III-a: Approaches to Achieving Safety
Chair: P. Zuidema (Nagra)
Rapporteur: S. Voinis (Andra)
The presentations focussed on:
- Siting and design strategy, e.g. precautionary principle, reversibility, flexibility principles, multi-barrier principles.
- Management strategy, including quality plan, how to adapt to stakeholders’ requirements, allocation of resources, co-ordination activities.
- Assessment strategy, e.g. Management of uncertainties, approaches.
Session III-b: The Scientific and Technical Basis for Assessing Safety
- Introduction: Review of the Preliminary Results of the NEA Survey on International Experience in the Safety Case (INTESC)
J. Andersson (JA Streamflow AB)
- Bátaapáti Repository (Hungary): Evolution of the Safety Case
M. Goldsworthy, P. Molnar, G. Danko (Golder Associates); Z. Nagy and F. Frigyesi (PURAM)
- An Iterative Approach to Achieving Safety: Application in the Dossier Argile 2005
B. Cahen, S. Voinis and L. Griffault (Andra)
- Developing a Safety Case for Ontario Power Generation’s L&ILW Deep Geologic Repository
H. Leung, P. Gierszewski, T. Kempe, R. Heystee, and M. Jensen (OPG)
- Development of a Methodology for an Environmental Safety Case in the UK
L.E.F. Bailey (UK Nirex Ltd.)
- Strategy for Safety Case Development: Impact of a Volunteer Approach to Siting a Japanese HLW Repository
K. Kitayama, K. Ishiguro, M. Takeuchi, H. Tsuchi, T. Kato, Y. Sakabe and K. Wakasugi (NUMO)
- The Canadian Nuclear Regulatory Process and Use of the Safety Case for Demonstrating the Long-term Safety of Radioactive Waste
P. Flavelle and M. Ben Belfadhel (CNSC)
- The ONDRAF/NIRAS Safety Strategy for the Disposal of B&C Wastes
A. Dierckx, W. Cool, P. De Preter, P. Lalieux (ONDRAF/NIRAS) and P. Smith (SAM Ltd.)
- Developing an Advanced Safety Concept for a HLW Repository in Rock Salt
J. Krone, N. Müller-Hoeppe (DBE Technology); W. Brewitz, J. Mönig (GRS-Braunschweig), M. Wallner and J.R. Weber (BGR)
Chair: K-J. Röhlig (GRS-Köln)
Rapporteur: F. Mompeán (NEA)
The presentations focussed on:
- System concept: components, safety functions, timescales, design constraints and requirements, challenges in technology.
- Scientific and technical information and understanding, confidence in the scientific and technical understanding, management of FEPs, handling diverse sources of information.
- Methods, models, computer codes and databases: Approaches, FEPs, choice of scenarios.
Research commissioned by regulatory bodies vis-à-vis programme priorities.
Session III-c: Evaluating and Documenting the Confidence in Safety
Chair: H. Umeki (JAEA)
Rapporteur: J. Andersson (JA Streamflow AB)
The presentations focussed on:
- Statement of confidence.
- Evaluating uncertainty in the context of confidence.
- Compliance measures and safety indicators.
- Quality plan and peer reviews (internal and external).
- Elements of the Safety Case for the Morsleben Repository Based on Probabilistic Modeling
J. Wollrath (BfS); M. Niemeyer, G. Resele (Colenco Power Engineering AG) D A. Becker and P. Hirsekorn (GRS)
- European Pilot Study on the Regulatory Review of the Safety Case for Geological Disposal of Radioactive Waste
F. Besnus (IRSN), J. Vigfusson (HSK), R. Smith (UK EA), V. Nys (AVN), G. Bruno (EC), P. Metcalf (IAEA), C. Ruiz Lopez (CSN), E. Ruokola (STUK), M. Jensen (SSI), K-J. Röhlig (GRS-Köln) and P. Bodenez (ASN)
- From Initial Safety Considerations to a Final Safety Case: Forms and Purposes of Safety Analysis during a Disposal Project’s Lifetime
J. Vigfusson (HSK)
- To What Extent Can Natural Analogues Contribute to the Safety Case of High-Level Waste Repositories (Abstract)
U. Noseck, W. Brewitz and I. Müller-Lyda (GRS)
- Geological Repository Programme in the Czech Republic– Current State of The Safety Case (Abstract)
S. Konopásková (RAWRA)
- Application of Archaeological Analogues for Repository Safety Case: Arguments Supporting the Waste Container Lifetime (Abstract)
H. Yoshikawa, K. Ueno and M. Yui (JAEA)
- Application of a Timeframes Approach to Performance Assessment (Abstract)
M.J. Poole (UK Nirex Ltd.)
- Safety Case for Radioactive Waste Disposal Facilities; Guidance on Confidence Building and Regulatory Review, IAEA ASAM Coordinated Research Project (Abstract)
M. Ben Belfadhel (CNSC), D.G. Bennett (Consultant), P. Metcalf (IAEA), V. Nys (AVN) and W. Goldammer (Consultant)
- 14C in the Safety Case (Abstract)
G. Bracke and W. Müller (Institute for Safety Technology)
- Pre-closure Safety Analysis for Seismically Initiated Event Sequences (Abstract)
M.J. Shah (US-NRC)
- Safety Assessments of Ultimate Isolation of Radioactive Waste in Deep Geological Formations in Russia: Objectives, Problems, Prospects (Abstract)
T.A. Gupalo (FSUE VNIPIpromtekhnologii)
- Development of the Safety Case of Geologic Repository in Korea (Abstract)
C-H. Kang, Y-M. Lee and Y-S. Hwang (KAERI)
Day 3 - 25 January 2007
Session III-c: Evaluating and Documenting the Confidence in Safety (continued)
Session IV: The Embedding of the Safety Case in Societal Dialogue and Decision Making
Chair: A. Hooper (Nirex)
Rapporteur: B. Stromberg (SKI)
Moderator: E. Van Hove (University of Antwerp)
Rapporteur: C. Pescatore (NEA)
The aim was to give the floor to the audience: opinion, discussion, open questions. The moderator gave a short summary and set forth questions for discussion.
Session V: Report on the Meeting
Chair: A. van Luik (US-DOE)
Rapporteur: P. Swift (SNL)
An overview was provided of the themes, progress, and conclusions reflected during the symposium.
Last updated: 7 February 2007