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Compilation and Evaluation of Fission Yield Nuclear Data Iaea, Vienna, 2000 Iaea-Tecdoc-1168 Issn 1011–4289

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Compilation and Evaluation of Fission Yield Nuclear Data Iaea, Vienna, 2000 Iaea-Tecdoc-1168 Issn 1011–4289 IAEA-TECDOC-1168 Compilation and evaluation of fission yield nuclear data Final report of a co-ordinated research project 1991–1996 December 2000 The originating Section of this publication in the IAEA was: Nuclear Data Section International Atomic Energy Agency Wagramer Strasse 5 P.O. Box 100 A-1400 Vienna, Austria COMPILATION AND EVALUATION OF FISSION YIELD NUCLEAR DATA IAEA, VIENNA, 2000 IAEA-TECDOC-1168 ISSN 1011–4289 © IAEA, 2000 Printed by the IAEA in Austria December 2000 FOREWORD Fission product yields are required at several stages of the nuclear fuel cycle and are therefore included in all large international data files for reactor calculations and related applications. Such files are maintained and disseminated by the Nuclear Data Section of the IAEA as a member of an international data centres network. Users of these data are from the fields of reactor design and operation, waste management and nuclear materials safeguards, all of which are essential parts of the IAEA programme. In the 1980s, the number of measured fission yields increased so drastically that the manpower available for evaluating them to meet specific user needs was insufficient. To cope with this task, it was concluded in several meetings on fission product nuclear data, some of them convened by the IAEA, that international co-operation was required, and an IAEA co-ordinated research project (CRP) was recommended. This recommendation was endorsed by the International Nuclear Data Committee, an advisory body for the nuclear data programme of the IAEA. As a consequence, the CRP on the Compilation and Evaluation of Fission Yield Nuclear Data was initiated in 1991, after its scope, objectives and tasks had been defined by a preparatory meeting. The different tasks, such as special evaluations and development of improved methods, were distributed among participants. The results of the research work were discussed and approved by all participants in research co-ordination meetings. For a successful development of theoretical and empirical models, experiments had to be recommended and their results to be awaited, which made necessary an extension of the CRP by two years. This TECDOC is the result of a joint effort of all participants in this CRP. The individual sections represent CRP tasks and were prepared by the participants responsible for doing the research, some of which comprise significant new scientific developments. The appendices to this book contain voluminous tables and are therefore enclosed as a CD-ROM, which also includes a computer program for calculating fission yields. For the availability of evaluations, data files or tabulations contained or described in this book the reader is referred to the addresses given in Chapter 3 or in the list of CRP participants. The IAEA wishes to thank all CRP participants who contributed to the success of the CRP and to this publication, namely: H.O. Denschlag (Chapter 2); T.R. England (Section 7.1); A.A. Goverdovski (Section 5.2); M.F. James (Sections 4.4 and 7.2); Liu Tingjin (Sections 5.1, 6.1, 6.3 and 7.4); R.W. Mills (Sections 4.4, 6.2 and 7.2); G. Rudstam (Section 4.3); F. Storrer (Section 3.2); A.C. Wahl (Sections 4.1, 4.2 and 7.4) and Wang Dao (Sections 6.3 and 7.3). The IAEA officer responsible for the project and this publication was M. Lammer of the Division of Physical and Chemical Sciences. EDITORIAL NOTE The use of particular designations of countries or territories does not imply any judgement by the publisher, the IAEA, as to the legal status of such countries or territories, of their authorities and institutions or of the delimitation of their boundaries. The mention of names of specific companies or products (whether or not indicated as registered) does not imply any intention to infringe proprietary rights, nor should it be construed as an endorsement or recommendation on the part of the IAEA. CONTENTS CHAPTER 1. INTRODUCTION AND SUMMARY OF THE CO-ORDINATED RESEARCH PROJECT.......................................................1 1.1. Requirements for fission yields ...............................................................................1 1.1.1. Fission yields in application fields...............................................................1 1.1.2. Types of required fission yields...................................................................2 1.2. Fission yield evaluation and the need for a CRP .....................................................3 1.2.1. Fission yield evaluation before the CRP and needs for improvements .......3 1.2.2. The need for co-operation ...........................................................................4 1.2.3. Scope, goals and tasks of the CRP...............................................................5 1.2.4. Current fission yield evaluations .................................................................6 1.3. Summary of work, conclusions and recommendations............................................8 1.3.1. Work during the CRP ..................................................................................8 1.3.2. Fission yield measurements .........................................................................9 1.3.3. Compilation of fission yields.....................................................................10 1.3.4. Model calculations.....................................................................................10 1.3.5. Ternary fission yields .............................................................................. 11 1.3.6. Energy dependence of fission yields..........................................................12 1.3.7. Correlations of experimental yields...........................................................12 1.3.8. Reference fission yields .............................................................................13 1.3.9. Evaluation of fission yields........................................................................13 1.3.10. CRP achievements and open problems......................................................13 References to Chapter 1 ............................................................................................................14 CHAPTER 2. TECHNIQUES OF FISSION YIELD MEASUREMENTS AND INHERENT ERROR MARGINS .....................................................................16 2.1. Introduction............................................................................................................16 2.2. Yield definitions.....................................................................................................16 2.3. General problems in fission yield determination ...................................................18 2.3.1. Absolute fission rate/reference yields........................................................18 2.3.2. Nuclear reactions of fission products.........................................................19 2.3.3. Neutron energy spectra ..............................................................................19 2.3.4. Self shielding.............................................................................................19 2.4. Single experimental techniques .............................................................................20 2.4.1. Radiochemical methods.............................................................................20 2.4.2. Classical mass spectrometry ......................................................................21 2.4.3. Direct C ray spectroscopy ...........................................................................22 2.4.4. Measurements of unstopped fission fragments..........................................23 2.5. Outlook: New trends and developments ................................................................29 2.5.1. Multiparameter measurements...................................................................29 2.5.2. Fission in inverse kinematics.....................................................................30 2.6. Requirements for publications ...............................................................................30 References to Chapter 2 ............................................................................................................31 CHAPTER 3. COMPUTERIZED INFORMATION SYSTEMS.............................................36 3.1. International information systems..........................................................................36 3.1.1. The Nuclear Data Centres Network...........................................................36 3.1.2. INIS............................................................................................................38 3.2. Other systems and retrieval programs....................................................................39 3.2.1. Use of computerized information systems.................................................39 3.2.2. Software recently developed to display nuclear data.................................39 3.2.3. The three main nuclear data centres in Europe and in the USA providing databases and on-line services..................................................42 References to Chapter 3 ............................................................................................................44 CHAPTER 4. MODEL CALCULATIONS..............................................................................45 4.1. Models for mass distribution and Wahl’s model ...................................................45 References to Section 4.1 ................................................................................................57
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