Nuclear Science 2015 Review of Integral Experiments for Minor Actinide Management Review Review of Integral Experiments for Minor Actinide Management NEA Nuclear Science Review of Integral Experiments for Minor Actinide Management OECD 2015 NEA No. 7222 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. The Organisation provides a setting where governments can compare policy experiences, seek answers to common problems, identify good practice and work to co-ordinate domestic and international policies. The OECD member countries are: Australia, Austria, Belgium, Canada, Chile, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Israel, Italy, Japan, Luxembourg, Mexico, the Netherlands, New Zealand, 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 takes part in the work of the OECD. OECD Publishing disseminates widely the results of the Organisation’s statistics gathering and research on economic, social and environmental issues, as well as the conventions, guidelines and standards agreed by its members. This work is published on the responsibility of the OECD Secretary-General. NUCLEAR ENERGY AGENCY The OECD Nuclear Energy Agency (NEA) was established on 1 February 1958. Current NEA membership consists of 31 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 Russian Federation, 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; – 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. This document and any map included herein are without prejudice to the status of or sovereignty over any territory, to the delimitation of international frontiers and boundaries and to the name of any territory, city or area. Corrigenda to OECD publications may be found online at: www.oecd.org/publishing/corrigenda. © OECD 2015 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 Spent nuclear fuel contains minor actinides (MAs) such as neptunium, americium and curium, which require careful management. This becomes even more important when mixed oxide (MOX) fuel is being used on a large scale since more MAs will accumulate in the spent fuel. One way to manage these MAs is to transmute them in nuclear reactors, such as light water reactors, fast reactors or accelerator-driven subcritical systems. The transmutation of MAs is, however, not straightforward, as the loading of MAs generally affects physics parameters, such as coolant void, Doppler and burn-up reactivity. In addition, due to a lack of measured MA data, and by extension accurate MA nuclear data, it remains difficult to establish a detailed design of transmutation systems with the capacity to precisely predict the composition of the spent fuel. Nuclear data of the major actinides, such as 235U, 238U and 239Pu, are based on a vast number of differential and integral experiments, using accelerators, critical facilities and experimental reactors. Integral experiments on MAs are much more difficult because of material handling restrictions at facilities, the difficulty of sample preparation and the need to improve measurement techniques to reduce the influence of background radiation. Moreover, most facilities for nuclear data measurements and validation are older facilities. Therefore, the NEA Nuclear Science Committee (NSC) decided to establish an Expert Group on Integral Experiments for Minor Actinide Management (EGIEMAM) to critically review integral experiments, recommend additional integral experiments for validating MA nuclear data and investigate the potential for establishing an international framework with a view to facilitating integral experiments for MA management. The EGIEMAM has recommended integral measurements of several minor actinide nuclides from the viewpoint of the design of transmutation systems and of fuel cycles. New actions have been proposed for reactor physics and irradiation experiments, and recommendations have been made for an international comparison of the analysis of integral experiments for minor actinides. The expert group has worked closely with the Working Party on Scientific Issues of Reactor Systems (WPRS), the Working Party on Scientific Issues of the Fuel Cycle (WPFC) and the Working Party on International Nuclear Data Evaluation Co-operation (WPEC). The relevant activities of these working parties include minor actinide burning in thermal reactors (MA-ThR), the International Reactor Physics Experiment Evaluation (IRPhE) Project, a comparative study on homogeneous and heterogeneous recycling of transuranics (TRU) and on potential benefits of advanced fuel cycles with partitioning and transmutation, meeting nuclear data needs for advanced reactors and the combined use of integral experiments and covariance data. This report presents the main results of the discussions in the EGIEMAM, focusing on the requirements of nuclear data for MA management, the specification of important nuclear data for MA management, the review of existing integral data, the identification of bottlenecks and possible solutions, as well as the recommendation of an action programme for international co-operation. REVIEW OF INTEGRAL EXPERIMENTS FOR MINOR ACTINIDE MANAGEMENT, NEA No. 7222, © OECD 2015 3 ACKNOWLEDGEMENTS Acknowledgements The NEA Secretariat would like to acknowledge the contributions of members of the NEA Expert Group on Integral Experiments for Minor Actinide Management. In particular, work completed by the following experts for this report is greatly appreciated: C.S. Gil (KAERI), G. Glinatsis (ENEA), K. Hesketh (NNL), O. Iwamoto (JAEA), R. Jacqmin (CEA), Y. Khomyakov (IPPE), A. Kochetkov (SCK•CEN), M. Kormilitsyn (RIAR), S. Okajima (JAEA), G. Palmiotti (INL), G. Perret (PSI), A. Rineiski (KIT), V. Romanello (KIT), M. Salvatores (INL), D. Sweet (AMEC) and K. Tsujimoto (JAEA). This report is dedicated to the memory of Dr Richard D. McKnight, who passed away on 28 August 2013. Dr McKnight first came to Argonne National Laboratory (ANL) in the early 1970s to work on his PhD. An international expert in the field of reactor physics, criticality safety and nuclear data, Dr McKnight was well-known at the NEA for his enthusiastic and highly valued contributions in all of these technical areas over several decades. The authors and the NEA Secretariat would like to recognise Dr McKnight for his outstanding contributions and support. 4 REVIEW OF INTEGRAL EXPERIMENTS FOR MINOR ACTINIDE MANAGEMENT, NEA No. 7222, © OECD 2015 TABLE OF CONTENTS Table of contents Executive summary ........................................................................................................................9 1. Introduction ...............................................................................................................................17 2. Requirements of nuclear data for minor actinide management .....................................19 2.1 Status of MA nuclear data ..................................................................................................19