Nuclear Science NEA/NSC/WPNCS/DOC(2011)5 June 2011 www.oecd-nea.org Spent Nuclear Fuel Assay Data for Isotopic Validation State-of-the-art Report Nuclear Science NEA/NSC/WPNCS/DOC(2011)5 Spent Nuclear Fuel Assay Data for Isotopic Validation State-of-the-art Report Nuclear Science Committee Working Party on Nuclear Criticality Safety (WPNCS) Expert Group on Assay Data of Spent Nuclear Fuel (EGADSNF) © OECD 2011 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 34 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 1 February 1958. Current NEA membership consists of 30 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, Poland, Portugal, the Republic of Korea, the Slovak Republic, Slovenia, Spain, Sweden, Switzerland, Turkey, the United Kingdom and the United States. The European Commission 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 the 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. Corrigenda to OECD publications may be found online at: www.oecd.org/publishing/corrigenda. © OECD 2011 You can copy, download or print OECD content for your own use, and you can include excerpts from OECD publications, databases and multimedia products in your own documents, presentations, blogs, websites and teaching materials, provided that suitable acknowledgment of the OECD as source and copyright owner is given. All requests for public or commercial use and translation rights should be submitted to [email protected]. Requests for permission to photocopy portions of this material for public or commercial use shall be addressed directly to the Copyright Clearance Center (CCC) at [email protected] or the Centre français d'exploitation du droit de copie (CFC) [email protected]. FOREWORD Foreword Management of nuclear fuel is a key issue for many NEA member countries with operating or decommissioned nuclear power plants. In the area of nuclear criticality safety, burn-up credit is an accepted practice for more efficient and cost effective management of irradiated fuel which takes into account a decrease in the reactivity of spent fuel due to the burn-up. In many countries burn-up credit has been implemented for spent fuel transportation, dry storage, pool storage, and in areas of spent fuel reprocessing. In many other countries the technical basis for burn-up credit is being actively developed and advanced for use in spent fuel management safety and licensing. The OECD/NEA Nuclear Science Committee (NSC) has been active in the area of criticality safety of irradiated nuclear fuel since 1980. In 1991, the OECD/NEA NSC formed the working group that in 1997 became the Working Party on Nuclear Criticality Safety (WPNCS), and the Expert Group on Burn-up Credit Criticality (EGBUC) was formed to co-ordinate burn-up credit technical activities and benchmarks of the criticality safety for irradiated nuclear fuel. Within the EGBUC, the importance of experimental assay data for irradiated nuclear fuel compositions to support validation of computer codes and nuclear data libraries used to calculate isotopic compositions used in burn-up credit has been recognised and discussed. In the EGBUC and WPNCS meetings in 2006 at Aix-en-Provence, it was decided that an effort dedicated specially to the collection and analyses of nuclear fuel assay data should be initiated, and the new Expert Group on Assay Data of Spent Nuclear Fuel (EGADSNF) was established. Because of the importance of assay data to a broad range of nuclear safety topics, the new Expert Group consists not only of members from WPNCS but also members from the standing technical Committee on the Safety of Nuclear Installations (CSNI) and the working group for the Integration Group for the Safety Case (IGSC) of the Radioactive Waste Management Committee. This report discusses the technical activities of the EGADSNF and the associated efforts of many NEA member countries to compile and document a comprehensive database of assay data to support applications related to nuclear energy and irradiated fuel safety and management. The new contributions of assay data are reviewed, with a summary of the existing database, experimental radiochemical assay measurement methods and best practices, and an uncertainty analysis. Based on the review of new assay data compiled by NEA member countries, progress to update the OECD/NEA web-based nuclear fuel nuclide composition database SFCOMPO is discussed. SPENT NUCLEAR FUEL ASSAY DATA FOR ISOTOPIC VALIDATION – © OECD 2011 3 LEADING PARTICIPANTS OF THE EXPERT GROUP ON ASSAY DATA FOR SPENT NUCLEAR FUEL Leading participants of the Expert Group on Assay Data for Spent Nuclear Fuel ALEJANO, Consuelo – Consejo de Seguridad Nuclear (Spain) BOULANGER, Daniele – ONDRAF/NIRAS (Belgium) BRADY-RAAP, Michele – Pacific Northwest National Laboratory (United States) BRENNETOT, Rene – Commissariat à l’énergie atomique (France) CHRAPCIAK, Vladimir – VUJE (Slovakia) CONDE, Jose – Consejo de Seguridad Nuclear (CSN, Spain) GAULD, Ian (Chair) – Oak Ridge National Laboratory (United States) GULLIFORD, Jim – OECD Nuclear Energy Agency GYSEMANS, Mireille – SCK•CEN (Belgium) HAVLUJ, Frantisek – Nuclear Research Institute at Rez (Czech Republic) HENNEBACH, Maik – AREVA NP GmbH (Germany) HORDOSY, Gabor – Atomic Energy Research Institute – KFKI (Hungary) ISHIGURO, Katsuhiko – Nuclear Waste Management Organization – NUMO (Japan) JUTIER, Ludyvine – IRSN (France) KILGER, Robert – GRS (Germany) KROEGER, Helge – BFS (Germany) MARKOVA, Ludmila – Nuclear Research Institute at Rez (Czech Republic) McKNIGHT, Richard – Argonne National Laboratory (United States) MICHEL-SENDIS, Franco – OECD Nuclear Energy Agency MILLS, Robert – UK National Nuclear Laboratory (United Kingdom) NEUBER, Jens Christian – AREVA NP GmbH (Germany) ORTEGO, Pedro – SEA Ingenieria y Analisis de Blindajes S. (Spain) MENNERDAHL, Dennis – E Mennerdahl Systems (Sweden) RANTA-AHO, Anssu – Teollisuuden Voima Oyj – TVO (Finland) REICHE, Ingo – BFS (Germany) RIFFARD, Cecile – Commissariat à l’énergie atomique – CEA (France) RUGAMA, Yolanda – Electricite de France – EdF (France) SANTAMARINA, Alain – Commissariat à l’énergie atomique – CEA (France) SUYAMA, Kenya (Past Chair) – Japan Atomic Energy Agency – JAEA (Japan) VAN WINCKEL, Stefaan – ITU, Karlsruhe (Germany) YAMAMOTO, Toru – Japan Nuclear Energy Safety Organization – JNES (Japan) ZWICKY, Hans-Urs – Zwicky Consulting GmbH (Switzerland) ZIMMERMAN, Colin – UK National Nuclear Laboratory (United Kingdom) 4 SPENT NUCLEAR FUEL ASSAY DATA FOR ISOTOPIC VALIDATION – © OECD 2011 TABLE OF CONTENTS Table of Contents Foreword .................................................................................................................................................. 3 List