Radioactive Waste Management ISBN 978-92-64-99050-0 Safety Cases for Deep Geological Disposal of Radioactive Waste: Where Do We Stand? Symposium Proceedings Paris, France 23-25 January 2007 Organised by the OECD Nuclear Energy Agency (NEA) of the Organisation for Economic Co-operation and Development (OECD) in co-operation with the European Commission (EC) and the International Atomic Energy Agency (IAEA) © OECD 2008 NEA No. 6319 NUCLEAR ENERGY AGENCY ORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT ORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT The OECD is a unique forum where the governments of 30 democracies work together to address the economic, social and environmental challenges of globalisation. The OECD is also at the forefront of efforts to understand and to help governments respond to new developments and concerns, such as corporate governance, the information economy and the challenges of an ageing population. 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The opinions expressed and arguments employed herein do not necessarily reflect the official views of the Organisation or of the governments of its member countries. NUCLEAR ENERGY AGENCY The OECD Nuclear Energy Agency (NEA) was established on 1st February 1958 under the name of the OEEC European Nuclear Energy Agency. It received its present designation on 20th April 1972, when Japan became its first non-European full member. NEA membership today consists of 28 OECD member countries: Australia, Austria, Belgium, Canada, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Japan, Luxembourg, Mexico, the Netherlands, Norway, Portugal, Republic of Korea, the Slovak Republic, Spain, Sweden, Switzerland, Turkey, the United Kingdom and the United States. The Commission of the European Communities also takes part in the work of the Agency. The mission of the NEA is: to assist its member countries in maintaining and further developing, through international co-operation, the scientific, technological and legal bases required for a safe, environmentally friendly and economical use of nuclear energy for peaceful purposes, as well as to provide authoritative assessments and to forge common understandings on key issues, as input to government decisions on nuclear energy policy and to broader OECD policy analyses in areas such as energy and sustainable development. Specific areas of competence of the NEA include safety and regulation of nuclear activities, radioactive waste management, radiological protection, nuclear science, economic and technical analyses of the nuclear fuel cycle, nuclear law and liability, and public information. The NEA Data Bank provides nuclear data and computer program services for participating countries. In these and related tasks, the NEA works in close collaboration with the International Atomic Energy Agency in Vienna, with which it has a Co-operation Agreement, as well as with other international organisations in the nuclear field. © OECD 2008 OECD freely authorises the use, including the photocopy, of this material for private, non-commercial purposes. Permission to photocopy portions of this material for any public use or commercial purpose may be obtained from the Copyright Clearance Center (CCC) at [email protected] or the Centre français d’exploitation du droit de copie (CFC) [email protected]. All copies must retain the copyright and other proprietary notices in their original forms. All requests for other public or commercial uses of this material or for translation rights should be submitted to [email protected]. Cover credit: Deep Geologic Repository Concept at the Bruce Site (Canada). FOREWORD A safety case for the post-closure phase of a geological repository is a synthesis of evidence, analyses and arguments to quantify and substantiate that a repository will be safe after closure and beyond the time when active control of the facility can be relied upon. A safety case is presented, most often by organisations responsible for implementing waste disposal solutions, at specific points in the process of repository development. The International Symposium on Safety Cases for Deep Geological Disposal: Where Do We Stand? (held in January 2007 in Paris, France) covered practical experience in defining, planning and developing the elements of a safety case for deep geological disposal of radioactive waste. Presentations by invited speakers, including stakeholders, also addressed the communication and presentation of safety cases. The aims of the symposium were to: x Share practical experiences on preparing for, developing and documenting a safety case both at the technical and managerial levels (testing the concept of a safety case). x Share experiences on the regulatory perspective. What are the regulatory requirements and expectations of the safety case? Does the safety case provide answers? x Highlight the progress made in the last decade, the actual state of the art and the observed trends. x Assess the relevance of the international contributions in this field. x Receive indications useful to the future work programmes of the NEA and other international organisations. The symposium was organised by the Nuclear Energy Agency (NEA) of the Organisation for Economic Co-operation and Development (OECD), in co-operation with the European Commission (EC) and the International Atomic Energy Agency (IAEA). Participants in the symposium included approximately 150 representatives from implementer, regulatory, scientific and stakeholder organisations in nearly 20 countries and international organisations. These symposium proceedings represent a multitude of contributions in the development and communication of the safety case made during the past 15-20 years, thereby building on the experience and knowledge exchanged at the previous international symposium of 1989, also organised by the OECD Nuclear Energy Agency, the EC and the IAEA. In addition to the contributed papers, these proceedings include an overview of the symposium, a synthesis of lessons learnt from an international perspective and detailed session-by-session summaries of the symposium. 3 ACKNOWLEDGEMENTS The planning and implementation of the symposium were supported by the efforts of the programme committee, whose members were: Peter De Preter Agency for Radioactive Waste and Enriched Fissile Materials, ONDRAF/NIRAS, Belgium Bruno Cahen Agency for Radioactive Waste Management, Andra, France Sylvie Voinis Agency for Radioactive Waste Management, Andra, France Gérard Bruno Radiological Protection and Nuclear Safety Institute, IRSN, France Hiroyuki Umeki Japan Atomic Energy Agency, JAEA, Japan Jesús Alonso Empresa Nacional de Residuos Radiactivos, SA, ENRESA, Spain Bo Stromberg Swedish Nuclear Power Inspectorate, SKI, Sweden Piet Zuidema National Cooperative for the Disposal of Radioactive Waste, NAGRA, Switzerland Alan Hooper United Kingdom Nirex Limited, United Kingdom Abraham Van Luik Office of Civilian Radioactive Waste Management, Department of Energy, DOE, United States of America Michel Raynal European Commission, EC, Belgium Didier Louvat International Atomic Energy Agency, IAEA, Austria Claudio Pescatore Organisation for Economic Co-operation and Development, Nuclear Energy Agency, OECD/NEA, France Betsy Forinash Integration Group for the Safety Case, IGSC, Secretariat, OECD/NEA, France The proceedings were drafted with the support of the United States (US) Department of Energy (DOE), with consultation and review by the NEA Secretariat, the Programme Committee, and symposium authors, presenters, session chairs and rapporteurs. The NEA staff wishes to acknowledge in particular the efforts of representatives of the US DOE (Barbara Merrill of Bechtel SAIC Company, LLC, Las Vegas, Nevada; Peter Swift of US Sandia National Laboratories, Albuquerque, New Mexico; and Abraham Van Luik, US DOE, Las Vegas, Nevada) in materially aiding the production of these proceedings. 4 TABLE OF CONTENTS FOREWORD ..................................................................................................................................... 3 OVERVIEW OF THE SYMPOSIUM ............................................................................................. 9 DEVELOPMENT AND MATURITY OF THE SAFETY CASE: AN INTERNATIONAL PERSPECTIVE FROM THE NEA SECRETARIAT ................................................................... 15 Background .................................................................................................................................. 15 The Concept and Meaning of the “Safety Case” .........................................................................