THE NEW NUCLEAR FORENSICS Analysis of Nuclear Materials for Security Purposes edited by vitaly fedchenko The New Nuclear Forensics Analysis of Nuclear Materials for Security Purposes STOCKHOLM INTERNATIONAL PEACE RESEARCH INSTITUTE SIPRI is an independent international institute dedicated to research into conflict, armaments, arms control and disarmament. Established in 1966, SIPRI provides data, analysis and recommendations, based on open sources, to policymakers, researchers, media and the interested public. The Governing Board is not responsible for the views expressed in the publications of the Institute. GOVERNING BOARD Sven-Olof Petersson, Chairman (Sweden) Dr Dewi Fortuna Anwar (Indonesia) Dr Vladimir Baranovsky (Russia) Ambassador Lakhdar Brahimi (Algeria) Jayantha Dhanapala (Sri Lanka) Ambassador Wolfgang Ischinger (Germany) Professor Mary Kaldor (United Kingdom) The Director DIRECTOR Dr Ian Anthony (United Kingdom) Signalistgatan 9 SE-169 70 Solna, Sweden Telephone: +46 8 655 97 00 Fax: +46 8 655 97 33 Email: [email protected] Internet: www.sipri.org The New Nuclear Forensics Analysis of Nuclear Materials for Security Purposes EDITED BY VITALY FEDCHENKO OXFORD UNIVERSITY PRESS 2015 1 Great Clarendon Street, Oxford OX2 6DP, United Kingdom Oxford University Press is a department of the University of Oxford. It furthers the University’s objective of excellence in research, scholarship, and education by publishing worldwide. Oxford is a registered trade mark of Oxford University Press in the UK and in certain other countries © SIPRI 2015 The moral rights of the authors have been asserted All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, without the prior permission in writing of SIPRI, or as expressly permitted by law, or under terms agreed with the appropriate reprographics rights organizations. Enquiries concerning reproduction outside the scope of the above should be sent to SIPRI, Signalistgatan 9, SE-169 70 Solna, Sweden You must not circulate this book in any other form and you must impose the same condition on any acquirer British Library Cataloguing in Publication Data Data available Library of Congress Cataloging in Publication Data Data available ISBN 978–0–19–873664–6 Typeset and originated by SIPRI Printed in Great Britain by CPI Group (UK) Ltd, Croydon Links to third party websites are provided by Oxford in good faith and for information only. Oxford disclaims any responsibility for the materials contained in any third party website referenced in this work Contents Preface xiii Acknowledgements xv Abbreviations xvi Glossary xxi 1. Introduction 1 VITALY FEDCHENKO I. National security policies and the analysis of nuclear 1 materials II. Nuclear forensic analysis as a collective term 4 III. The applications and purposes of nuclear forensic analysis 7 Box 1.1. Definitions 6 Table 1.1. Applications of nuclear forensic analysis 8 Part I. Nuclear forensic methods 2. The process of nuclear forensic analysis 11 VITALY FEDCHENKO I. Sample collection and categorization 13 Sample collection 13 Sample categorization 16 II. Sample characterization 19 Material characteristics 19 Measurement techniques and equipment 19 III. Nuclear forensic interpretation 23 Signatures 23 The process of interpretation 25 Libraries, databases and archives 26 Table 2.1. Materials and their forms sampled for nuclear 12 forensic purposes Table 2.2. Categories of nuclear materials 16 Table 2.3. Categories of radioactive materials other than 17 nuclear materials Table 2.4. Categories of characteristics of materials or items 18 subject to measurement Table 2.5. Typical material characteristics categories and 20 measurement technique Table 2.6. Measurement techniques typical for sample 21 characterization in nuclear forensic analysis vi THE NEW NUCLEAR FORENSICS Appendix 2A. Basic facts and definitions related to measurement 34 SOPHIE GRAPE I. Terms and definitions 34 Accuracy and precision 35 Fundamental aspects of the measurand 36 Statistical distributions 37 Measuring errors 39 II. Assessment of a measurand 40 Currie classification scheme and data interpretation 41 III. Application to counting measurements 45 How good is the fit to data? 46 Figure 2A.1. Graphical representation of the terms accuracy 36 and precision using a dartboard Figure 2A.2. The normal distribution, the Poisson distribution and 38 Student’s t-distribution with three independent parameters Figure 2A.3. The standard normal distribution showing the maximum 42 acceptable error of the first kind 3. Inorganic mass spectrometry as a tool of destructive nuclear forensic 47 analysis KLAUS MAYER, MARIA WALLENIUS, ZSOLT VARGA, MAGNUS HEDBERG AND NICOLE ERDMANN I. Thermal ionization mass spectrometry 48 Principle and general description 49 Application of TIMS in nuclear forensics 50 II. Inductively coupled plasma mass spectrometry 52 Principle and general description 52 Determination of elemental composition and impurities 55 Isotope ratio measurements by multi-collector ICP-MS 58 Example of the use of ICP-MS in nuclear forensics 61 III. Secondary ion mass spectrometry 63 Principle and general description 63 Classical safeguards application of uranium particle 63 analysis by SIMS Examples of forensic application of SIMS analysis 67 IV. Other mass spectrometric techniques 68 Resonance ionization mass spectrometry 69 Accelerator mass spectrometry 73 Figure 3.1. Sample of uranium ore concentrate seized at Rotterdam in 50 2003, after arrival at the nuclear forensics laboratory Figure 3.2. A typical mass spectrum of the thorium fraction, obtained 56 from confiscated material for age measurement Figure 3.3. The lead-207 : lead-204 isotope-abundance ratio measured 60 in selected uranium ore concentrate samples CONTENTS vii Figure 3.4. The strontium-87 : strontium-86 isotope-abundance ratio 62 of selected uranium ore concentrate samples Figure 3.5. Scanning electron microscope picture of a conglomerate of 64 uranium particles Figure 3.6. Vacuum impactor 65 Figure 3.7. A large geometry SIMS instrument 66 Figure 3.8. Plot of individual particle analysis showing uranium-236 67 versus uranium-235 and uranium-234 versus uranium-235 Figure 3.9. The typical structure of a particle from a nuclear fuel 68 Figure 3.10. Resonance ionization mass spectrometry spectrum of 72 plutonium from a metal plate of natural uranium from the German nuclear programme of the 1940s Table 3.1. Nuclear forensic measurement methods 48 Table 3.2. Typical detection limits and precisions of inductively 58 coupled plasma mass spectrometry instruments for fissile nuclides 4. Gamma spectrometry as a tool of non-destructive nuclear forensic 74 analysis SOPHIE GRAPE I. The principle of gamma spectrometry 74 The physics behind gamma spectrometry 74 Electromagnetic interactions with matter 75 Measurement principles 75 II. Gamma spectrometry equipment 77 Detector types 78 III. Ability, demands and limitations of gamma detectors 83 Explanations for the peak width 85 Measurement time 87 Background radiation 89 IV. Special applications of gamma spectrometry 90 Airborne and air-related measurements 90 Underwater measurements 91 Underground experiments 92 Figure 4.1. Example of two Gaussian distributions with the same 84 centroid value but different resolutions 5. Sample characteristics and nuclear forensic signatures 93 KLAUS MAYER, MARIA WALLENIUS AND ZSOLT VARGA I. Physical characteristics and signatures 93 Metallic uranium and plutonium 94 Fuel pellets 95 Powders and liquids related to the nuclear fuel cycle 99 II. Chemical characteristics and signatures 101 Uranium compounds 102 Plutonium compounds 106 Common non-nuclear chemicals in the fuel cycle 107 viii THE NEW NUCLEAR FORENSICS III. Elemental characteristics and signatures 109 IV. Isotopic characteristics and signatures 111 Plutonium isotopes 111 Determination of the age of plutonium 113 Uranium isotopes 117 Other important stable isotope ratios 122 Figure 5.1. Uranium and plutonium metal in various shapes 94 Figure 5.2. Metallic cubes made of natural uranium used in the first 95 prototype reactors in Germany and the United States Figure 5.3. Aircraft counterweight 96 Figure 5.4. Examples of uranium oxide pellets used in nuclear power 96 reactors Figure 5.5. A uranium fuel pellet, showing dimensions and markings 98 Figure 5.6. Scanning electron microscopy images of the grain 98 morphology of two pellets from different manufacturers Figure 5.7. Lower magnification scanning electron microscopy images 100 of two samples of uranium ore concentrate Figure 5.8. Higher magnification scanning electron microscopy images 100 of two samples of uranium ore concentrate Figure 5.9. Photographs of two samples of uranium ore concentrate 101 Figure 5.10. The Fourier-transform infrared spectroscopy spectra of 102 chemical compounds found in uranium ore concentrate Figure 5.11. The infrared spectrum recorded for ammonium diuranate 104 from a sample of uranium ore concentrate Figure 5.12. The measured ion chromatogram for ammonium diuranat 105 from a sample of uranium ore concentrate Figure 5.13. The rare-earth elemental pattern of various uranium ores 110 and the respective uranium ore concentrates produced Figure 5.14. The plutonium-240 : plutonium-239 ratio versus the 114 plutonium-242 : plutonium-239 ratio in different reactor types Figure 5.15. The variation of main progeny-to-parent nuclide atom 115 ratios for the most important nuclear radionuclides as a function of time Figure 5.16.