Fission Product Yield Data for the Transmutation of Minor Actinide Nuclear Waste

353 Pages·2008·24.25 MB·English

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INTERNATIONAL ATOMIC ENERGY AGENCY
VIENNA
ISBN 92–0–115306–6
P1286_covI+IV_A4.indd 1 2008-04-16 10:23:54
FISSION PRODUCT YIELD DATA FOR
THE TRANSMUTATION OF MINOR
ACTINIDE NUCLEAR WASTE
The following States are Members of the International Atomic Energy Agency:
AFGHANISTAN GREECE NORWAY
ALBANIA GUATEMALA PAKISTAN
ALGERIA HAITI PALAU
ANGOLA HOLY SEE PANAMA
ARGENTINA HONDURAS PARAGUAY
ARMENIA HUNGARY PERU
AUSTRALIA ICELAND PHILIPPINES
AUSTRIA INDIA POLAND
AZERBAIJAN INDONESIA PORTUGAL
BANGLADESH IRAN, ISLAMIC REPUBLIC OF QATAR
BELARUS IRAQ REPUBLIC OF MOLDOVA
BELGIUM IRELAND ROMANIA
BELIZE ISRAEL RUSSIAN FEDERATION
BENIN ITALY SAUDI ARABIA
BOLIVIA JAMAICA SENEGAL
BOSNIA AND HERZEGOVINA JAPAN SERBIA
BOTSWANA JORDAN SEYCHELLES
BRAZIL KAZAKHSTAN SIERRA LEONE
BULGARIA KENYA SINGAPORE
BURKINA FASO KOREA, REPUBLIC OF SLOVAKIA
CAMEROON KUWAIT SLOVENIA
CANADA KYRGYZSTAN SOUTH AFRICA
CENTRAL AFRICAN LATVIA SPAIN
REPUBLIC LEBANON SRI LANKA
CHAD LIBERIA SUDAN
CHILE LIBYAN ARAB JAMAHIRIYA SWEDEN
CHINA LIECHTENSTEIN SWITZERLAND
COLOMBIA LITHUANIA SYRIAN ARAB REPUBLIC
COSTA RICA LUXEMBOURG TAJIKISTAN
CÔTE D’IVOIRE MADAGASCAR THAILAND
CROATIA MALAWI THE FORMER YUGOSLAV
CUBA MALAYSIA REPUBLIC OF MACEDONIA
CYPRUS MALI TUNISIA
CZECH REPUBLIC MALTA TURKEY
DEMOCRATIC REPUBLIC MARSHALL ISLANDS UGANDA
OF THE CONGO MAURITANIA UKRAINE
DENMARK MAURITIUS UNITED ARAB EMIRATES
DOMINICAN REPUBLIC MEXICO UNITED KINGDOM OF
ECUADOR MONACO GREAT BRITAIN AND
EGYPT MONGOLIA NORTHERN IRELAND
EL SALVADOR MONTENEGRO UNITED REPUBLIC
ERITREA MOROCCO OF TANZANIA
ESTONIA MOZAMBIQUE UNITED STATES OF AMERICA
ETHIOPIA MYANMAR URUGUAY
FINLAND NAMIBIA UZBEKISTAN
FRANCE NETHERLANDS VENEZUELA
GABON NEW ZEALAND VIETNAM
GEORGIA NICARAGUA YEMEN
GERMANY NIGER ZAMBIA
GHANA NIGERIA ZIMBABWE
The Agency’s Statute was approved on 23 October 1956 by the Conference on the Statute of the IAEA
held at United Nations Headquarters, New York; it entered into force on 29 July 1957. The Headquarters of the
Agency are situated in Vienna. Its principal objective is “to accelerate and enlarge the contribution of atomic
energy to peace, health and prosperity throughout the world’’.
SERIES
FISSION PRODUCT YIELD DATA FOR
THE TRANSMUTATION OF MINOR
ACTINIDE NUCLEAR WASTE
INTERNATIONAL ATOMIC ENERGY AGENCY
VIENNA, 2008
COPYRIGHT NOTICE
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© IAEA, 2008
Printed by the IAEA in Austria
April 2008
STI/PUB/1286
IAEA Library Cataloguing in Publication Data
Fission product yield data for the transmutation of minor actinide nuclear
waste. – Vienna : International Atomic Energy Agency, 2008.
p. ; 24 cm.
STI/PUB/1286
ISBN 92–0–115306–6
Includes bibliographical references.
1. Fission products — Measurement. 2. Radioactive wastes.
3. Transmutation (Chemistry). 4. Neutron cross-sections. 5. Fission
cross-sections — Measurement. I. International Atomic Energy
Agency.
IAEAL 08–00504
FOREWORD
A report issued by an international study group for the transmutation of nuclear waste using accelerator
driven systems has highlighted the need for specific sets of nuclear data. These authoritative requirements
include fission product yields at an intermediate incident neutron energy of up to 150 MeV.
Before the start of the present CRP on fission product yield data for the transmutation of nuclear waste,
only four types of evaluated fission yield data sets existed, namely for spontaneous fission, and for fission
induced by thermal, fast (or fission) spectrum, and by ‘high energy’ (14–15 MeV) neutrons. A new type of
evaluation for energy dependent neutron induced fission yields was required for this project. In view of the
scarcity of experimental data, such an evaluation has to be based on systematics and theoretical model calcula-
tions. Unlike fission cross-sections, where nuclear models are being used successfully for the calculation of
unmeasured cross-section ranges, such models or theories existed only for low energy fission yields. Hence the
CRP participants entered a completely new field of research for which the progress and outcome were unpre-
dictable. Clearly the ultimate goal of such an effort, namely an evaluation of energy dependent fission yields,
could not be realized within the perceived lifetime of a CRP.
The main emphasis of the CRP was on the development of adequate systematics and models for the
calculation of energy dependent fission yields up to 150 MeV incident neutron energy. Several problems had to
be solved, such as the correct choice of model parameters and multiplicity distributions of emitted neutrons, and
the effect of multi-chance fission. Models and systematics have been tested for lower energy yields, but they
failed to reproduce recent experimental data, particularly at higher energies, and the parameters had to be
modified. Other models have been developed from the analysis of experimental data in order to derive
systematic dependences and they were adapted in the course of the CRP to predict fission product yields. The
valuable role of the CRP in such work became evident during the meetings, at which the discussions formed a
fruitful basis for improvements to the models. The benchmark exercise revealed the true worth and predictive
capabilities of the systematics and theoretical models developed during the course of the CRP. Necessary
improvements and the direction of future studies were also revealed. These models have the potential to give
reliable predictions after implementation of the improvements suggested in this report.
A brief introduction and the various studies undertaken by individual participants are given at the
beginning of this publication, followed by a detailed description of the resulting overall achievements,
conclusions and recommendations of the CRP and a summary of the benchmark exercise and results. Additional
material is included on the enclosed CD-ROM, including compilations of the fission product yields, unedited
papers and all details of the benchmark exercise.
The IAEA wishes to thank all CRP participants for their contributions to the project. The IAEA
responsible officers were M. Lammer and A.L. Nichols of the Division of Physical and Chemical Sciences.
CONTRIBUTING AUTHORS
Denschlag, J.-O. Johannes-Gutenberg-Universität Mainz, Germany
Duijvestijn, M.C. Nuclear Research and Consultancy Group, Netherlands
Ethvignot, Th. Service de Physique Nucléaire, Commissariat à l’Énergie Atomique, France
Hambsch, F.-J. EC Joint Research Centre, Institute for Reference Materials and Measurements,
Belgium
Katakura, J. Japan Atomic Energy Agency, Japan
Kibkalo, Yu.V. SC Institute for Nuclear Research, Ukraine
Lammer, M. International Atomic Energy Agency
Tingjin, Liu China Institute of Atomic Energy, China
Maslov, V.M. Belarus Academy of Sciences, Belarus
Mills, R.W. Nexia Solutions, British Nuclear Fuels plc, United Kingdom
Wahl, A.C. Los Alamos National Laboratory, United States of America
Zhdanov, S.V. National Nuclear Centre, Kazakhstan
TECHNICAL ASSISTANCE
Nichols, A.L. International Atomic Energy Agency
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
1. FISSION PRODUCT YIELDS: MINOR ACTINIDES UP TO 150 MeV. . . . . . . . . . . . . . . . . . . . . . . 1
M. Lammer
1.1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1.1. Transmutation of nuclear waste . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1.2. New approach to fission yield evaluations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1.3. Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2. Modelling of fission fragment mass distributions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2.1. Fission process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2.2. Fission fragment mass distributions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2.3. Prediction of fission yields: Systematics and theoretical models . . . . . . . . . . . . . . . . . . . . . 3
1.3. Problems to be addressed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3.1. Experimental data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3.2. Collection of experimental data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3.3. Treatment of measured data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3.4. Multi-chance fission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.3.5. Neutron emission data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.3.6. Development of systematics and models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.3.7. Nuclear charge distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.4. CRP participants and tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.4.1. Participants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.4.2. Tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
References to Section 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2. EXPERIMENTAL DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1. Measurements of product yields from fission reactions induced by high energy
neutrons, protons, deuterons, alpha particles, other charged particles and photons —
Collection of references. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
J.-O. Denschlag
References to Section 2.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2. Measurements of the energy dependence of fission yields for 238U(n,f) from threshold
to 200 MeV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Th. Ethvignot
2.2.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.2.2. Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.2.3. Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.2.4. Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
References to Section 2.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3. EVALUATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3.1. Actinide nucleon induced fission cross-sections up to 200 MeV . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
V.M. Maslov
3.1.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3.1.2. Statistical model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
3.1.3. Analysis of fission cross-sections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
3.1.4. Concluding remarks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
References to Section 3.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
3.2. Evaluated reference fission yield data file. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Liu Tingjin, Liang Qichang
3.2.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3.2.2. Evaluation method. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3.2.3. Results and recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
3.2.4. Concluding remarks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
References to Section 3.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
3.3. Evaluation of mass distribution data from 252Cf spontaneous fission . . . . . . . . . . . . . . . . . . . . . . 87
Liu Tingjin
3.3.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
3.3.2. Collection and evaluation of experimental data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
3.3.3. Processing of evaluated experimental data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
3.3.4. Results and discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
3.3.5. Concluding remarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
References to Section 3.3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Annex 3.3.1. Evaluated experimental data for 252Cf spontaneous fission mass distribution. . . . 96
Annex 3.3.2. Evaluated data set 1 for 252Cf spontaneous fission mass distribution: Normal
spline fit without any restriction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
Annex 3.3.3. Evaluated data set 2 for 252Cf spontaneous fission mass distribution: Spline fit
with symmetric reflection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
3.4. Examination of possible evaluation methods for future energy dependent fission product
yield data sets required for minor actinide incineration, and other considerations. . . . . . . . . . . . 101
R.W. Mills
3.4.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
3.4.2. Thoughts on future evaluations utilizing the fission product yield methodologies
described by CRP participants. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
3.4.3. Collation of references and data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
3.4.4. Benchmark exercise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
3.4.5. Progress in the UK fission product yield file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
References to Section 3.4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
4. SYSTEMATICS AND MODELS FOR THE PREDICTION OF FISSION YIELDS . . . . . . . . . . . . 111
4.1. Prediction of fission mass yield distributions based on cross-section evaluations . . . . . . . . . . . . . 111
F.-J. Hambsch
4.1.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
4.1.2. Statistical model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
4.1.3. Results and discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
4.1.4. Concluding remarks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
References to Section 4.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
4.2. Systematics of fission product yields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
A.C. Wahl
4.2.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
4.2.2. Mass distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
4.2.3. Nuclear charge distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
4.2.4. Models for neutron emission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
4.2.5. Fast neutron induced fission. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
4.2.6. Calculation of fission yields from systematics — CYF program . . . . . . . . . . . . . . . . . . . . . 145
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
References to Section 4.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
4.3. Five Gaussian systematics for fission product mass yields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
Jun-ichi Katakura
4.3.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
4.3.2. Basic structure of present systematics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
4.3.3. Examination of parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
4.3.4. Description of parameters in the systematics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
4.3.5. Comparisons with measured mass yields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
4.3.6. Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
References to Section 4.3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
4.4. Phenomenological model for fragment mass and charge distribution in actinide
nuclei fission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
Yu.V. Kibkalo
4.4.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
4.4.2. Energy dependence of nuclear fission cross-sections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
4.4.3. Angular momentum dependence of fission fragment mass distributions. . . . . . . . . . . . . . 159
4.4.4. Fragment mass distributions for photofission. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
4.4.5. Fragment mass distributions from fission by α particles. . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
4.4.6. Fragment mass distribution for 238U fission by neutrons . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
4.4.7. Fragment mass distribution for spontaneous fission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
4.4.8. Description of fission fragment mass and charge distributions . . . . . . . . . . . . . . . . . . . . . . 171
4.4.9. Concluding remarks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
References to Section 4.4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
4.5. Modal approach to the description of fragment mass yields in neutron and proton induced
fission of actinides at incident particle energies from 5 to 200 MeV . . . . . . . . . . . . . . . . . . . . . . . . 183
D.M. Gorodisskiy, S.I. Mulgin, A.Ya. Rusanov, S.V. Zhdanov
4.5.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
4.5.2. Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
4.5.3. Multi-modal analysis of MEDs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
4.5.4. Discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
4.5.5. Systematics of fragment mass yields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
4.5.6. PYF code. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
4.5.7. Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207
References to Section 4.5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208
4.6. Fission yields in nucleon induced reactions at intermediate energies . . . . . . . . . . . . . . . . . . . . . . . 210
M.C. Duijvestijn, A.J. Koning
4.6.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
4.6.2. Compilation of proton induced fission product isotope yields. . . . . . . . . . . . . . . . . . . . . . . 210
4.6.3. Activation experiment on proton induced fission of natW, 197Au, natPb, 208Pb
and 232Th at 190 MeV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
4.6.4. Predictions of fission yields at intermediate energies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219
4.6.5. Summary and outlook. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
References to Section 4.6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
5. NEW MODELS AND SYSTEMATICS: DEFINITIONS AND TESTING . . . . . . . . . . . . . . . . . . . . . 239
M. Lammer
5.1. Output and products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
5.1.1. Data files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
5.1.2. Dedicated studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
5.1.3. Models and systematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240
5.2. Benchmark exercise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
5.2.1. Benchmark exercise — general remarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
5.2.2. Summary of results and intercomparisons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
5.2.3. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
5.3. Conclusions and recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
References to Section 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251