Review of Criticality Accidents

157 Pages·2000·12.607 MB·English

A Review of
Criticality Accidents
2000 Revision
Issued: May 2000
United States Authors:
Thomas P. McLaughlin
Shean P. Monahan
Norman L. Pruvost*
Russian Federation Authors:
Vladimir V.Frolov**
Boris G. Ryazanov***
Victor I. Sviridov+
WXXES= FROMBEST AVAILABLECOPY
*Senior Analyst. Galaxy Computer Services, Inc., Santa Fe, NM 87501.
**LeadResearcher. Institute ofPhysics and Power Engineering (IPPE),
Obninsk, Russia 249020.
***Headof the Nuclear Safety Division. Institute of Physics and Power
Engineering (IPPE), Obninsk, Russia 249020.
‘Head of the Nuclear Safety Laboratory. Institute of Physics and Power
Engineering (IPPE), Obninsk, Russia 249020.
Los Alamos
NATIONAL LABORATORY
.
LosAlamos,NewMexico87545
DISCLAIMER
This report was.prepared as an account of work sponsored
by an agency of the United States Government. Neither
the United States Government nor anyagencythereof, nor
any of their employees, make any warranty, express or
implied, or assumes any legal Inability or responsibility for
the accuracy, completeness, or usefulness of any
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represents that its use would not infringe privately owned
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manufacturer, or otherwise does not necessarily constitute
or imply its endorsement, recommendation, or favoring by
the United States Government or any agency thereof. The
views and opinions of authors expressed herein do not
necessarily state or reflect those of the United States
Government or any agency thereof.
DISCLAIMER
Portions of this document may be illegible
in electronic image products. Images are
produced from the best available original
document.
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FOREWARD
We, of the early decades at Pajarito Site, Los Alamos, were near a number of accidental
bursts of radiation in the course of critical experiments. In the first of these, the person at the
controls exclaimed “a disaster!” With a quarter-mile separation protecting operators, each of
these “disasters” proved to be without consequence. Nevertheless, errors that led to them should
have been avoided, and accounts of these accidents were disseminated to discourage recurrence.
A serious process criticality accident at Los Alamos was another matter, because protection
of operators was supposed to have been provided by criticality safety practices instead of built-in
features such as shielding or distance. In this case, publication brought out obscure causes that
demanded consideration in the discipline of criticality safety.
The value of publication of both types of accident-led William R. Stratton of the Pajanto
Group to bring together all available descriptions in his A Review of Criticality Accidents, the
linchpin of this account.
Hugh C. Paxton
Los Alamos, NM
August 1999

PREFACE
This document is the second revision of A Review of Criticality Accidents. The first was
issued as report LA-3611 in 1967 and authored by William R. Stratton. 1At that time, he was a
staff member in the Critical Experiments Group at Los Alamos and a member of the Atomic
Energy Commission’s Advisory Committee on Reactor Safeguards. The first revision was pub-
lished with the same title in 1989 as document NCT-04.2 This revision was carried out by
David R. Smith, a colleague of Stratton’s in the Critical Experiment Group during the 60’s and
70’s and the Laboratory’s Criticality Safety Ot%cer. In 1980, the criticality safety function was
removed from the Critical Experiments Group and made a separate entity in the Laboratory’s
Health and Safety organization with Smith as the first group leader.
With the advent of cooperative research and information exchanges between scientists in the
Russian Federation (Russia, R.F.) of the Former Soviet Union and Los Alamos National Labora-
tory in the early 1990s, discussions began to investigate possible joint work in the field of nuclear
criticality safety (to be referred to hereafter as simply “criticality safety”). By 1994, interactions
were ongoing between Los Alamos and four Russian sites with criticality safety interests: the
Institute of Physics and Power Engineering (IPPE) in Obnins~ the All Russian Scientific Re-
search Institute of Experimental Physics (VNIIEF) in Sarov (formerly Arzamas- 16); the All
Russian Scientific Research Institute of Technical Physics (VNIITF) in Snezhinsk (formerly
Chelyabinsk-70); and the Kurchatov Institute (KI) in Moscow.
Criticality safety staff at IPPE have regulatory oversight responsibility for the four major
fissile material production and handling sites where process facility criticality accidents have
occurred. These are the Mayak Production Association (Mayak), the Siberian Chemical Combine
(Tomsk-7) in Seversk, the Electrostal Machine Building Plant in Electrostal, and the Novosibirsk
Chemical Concentrates Plant in Novosibirsk. Thus, criticality safety staff from these four sites
were directly involved in the 13 Russian process accidents described herein. The other three
institutes, Arzamas- 16, Chelyabinsk-70, and the Kurchatov Institute have critical experiment and
reactor development capabilities; accidents in this category have occurred at these sites.
This report, planned to be published in both English and Russian language versions, is the
fruit of cooperative efforts of criticality safety specialists in both countries. It not only includes
all of the Russian criticality accidents, but also revises the US and UK process facility accidents
reported in the second edition. The revisions to the US and UK process accident descriptions are
mainly expansions of the text to include information that was previously only in reference docu-
ments. In a few instances, technical corrections were necessary. The expanded descriptions are
provided for the benefit of the broader audience that this document has been attracting over the
years.
Finally, as this report was almost to be printed in September 1999, a criticality accident
occurred at the JCO fuel processing facility in Japan. Printing was delayed until this most recent
accident could be fully understood and documented herein. It is the goal of the authors that with
this expanded report, the causes of criticality accidents and their consequences will be better
understood and the safety and efllciency of operations with significant quantities of llssile mate-
rials will be enhanced.
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ACKNOWLEDGMENTS
Many people have contributed significantly to the completion of this second revision of
A Review of Criticality Accidenls. The relative importance of the contribution of each person is
not intended by the ordering of names. Each person made a necessary contribution to the final
document.
For the Russian accident information:
Gennadiy T. Kirillov—Tomsk-7
Mikhail I. Kuvshinov—Arzamas- 16
Dimitri M. Parfanovich-Kurchatov Institute
Aleksandr V.Romanov—Electrostal “
Igor G. Smimov—Arzamas- 16
Gennadiy S. Starodubtsev-Mayak
A. P.Suslov—Mayak
Vladimir Teryokhin-Chelyabinsk-70
Aleksandr G. Ustyugov—Novosibirsk
Sergei Vorontsov—Arzamas- 16
Isao Takeshita-Japanese Atomic Energy Research Institute
The U.S. authors are indebted to each of the above for answering innumerable questions,
often by telephone, at home, late at night in Russia in order to accommodate a mid-morning
meeting time in Los Alamos. In particular, we acknowledge that Igor G. Smimov, Sergei
Vorontsov, Mikhail I. Kuvshinov, and Vladimir Teryokhin endured about three hours of “interro-
gation” one night at one of the Los Alamos authors’ homes, and were recompensed only with a
meal. On another occasion, after a similar evening of questions and discussion, Gemadiy
Starodubtsev agreed to return two evenings later for another four-hour session, each time accept-
ing only a meal as payment. These evening sessions took place after a full day of other business
in Los Alamos. Gennadiy Starodubtsev was motivated by a personal desire to contribute to an
accurate, complete recounting of the seven Mayak accidents.
Barbara D. Henderson played a key administrative role in keeping the project on track in
many regards. She has been involved with the project from the time it was only an ill-defined
goal to the final product, a nearly eight-year span.
Charles T. Rombough assisted with this project for more than two years. He has provided
seamless transmission of information, text, figures, and photographs, in both English and Rus-
sian languages, in addition to producing electronic files of all intermediate drafts.
Nellie Schachowskoj Shropshire and Olga Vlddo provided both interpretation and translation
services for the many meetings, telephone calls, emails, and intermediate drafts.
Hugh C. Paxton once again, at the young ageof91 years, provided insightful and thought-
provoking comments on the technical content. He also contributed sharp editorial comments.
David R. Smith provided valuable comments on various drafts, particularly on lessons
learned from the accidents.
William R. Stratton provided valuable comments on early drafts of the report.
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Tom Jones was invaluable in generating most of the schematics found in Part I and in
Appendix B, under significant time constraints.
Jerry McKamy of the Department of Energy and Chuck Nllsen of the Nuclear Regulatory
Commission were instrumental in recognizing the value of and providing financial support for
this project. They both also exhibited a vanishing talent by not micromanaging the project, for
which the authors are grateful.
CONTENTS
FOREWORD .................................................................................................................................. v
PREFACE ..................................................................................................................................... vii
ACKNOWLEDGMENTS .............................................................................................................ix
TABLE OF CONTENTS ...............................................................................................................xi
LIST OF FIGURES ......................................................................................................................xv
LIST OF TABLES .......................................................................................................................xix
ABSTRACT ................................................................................................................................... 1
INTRODUCTION .......................................................................................................................... 1
I. PROCESS ACCIDENTS ...........................................................................................................2
A. ACCIDENT DESCRIPTIONS ............................................................................................2
1.Mayak Production Association, 15 March 1953 ...........................................................7
2. Mayak Production Association, 21 April 1957 .............................................................9
3. Mayak Production Association, 2 January 1958 ......................................................... 11
4. Oak Ridge Y-12 Plant, 16June 1958 ........................................................................... 13
5. Los Alamos Scientific Laboratory, 30 December 1958 ............................................... 16
6. Idaho Chemical Processing Plant, 16 October 1959 ................................................... 18
7. Mayak Production Association, 5 December 1960 ..................................................... 19
8. Idaho Chemical Processing Plant, 25 January 1961 ....................................................22
9. Siberian Chemical Combine, 14July 1961 ................................................................. 23
10. Hanford Works, 7 April 1962 ......................................................................................27
11. Mayak Production Association, 7 September 1962 .....................................................28
12. Siberian Chemical Combine, 30 January 1963 ........................................................... 30
13. SiberianChemical Combine,2December 1963 ......................................................... 31
14. United Nuclear Fuels Recovery Plant, 24 July 1964 ...................................................33
15. Electrostal Machine Building Plant, 3 November 1965 ..............................................35
16. Mayak Production Association, 16 December 1965 ................................................... 37
17. Mayak Production Association, 10 December 1968 ...................................................40
18. Windscale Works, 24 August 1970 ..............................................................................43
19. Idaho Chemical Processing Plant, 17October 1978 ...................................................45
20. Siberian Chemical Combine, 13 December 1978 .......................................................47
21. Novosibirsk Chemical Concentration Plant, 15May 1997 .........................................50
22. JCO Fuel Fabrication Plant, 30 September 1999 ........................................................53
B. PHYSICALANDNEUTRONICCHARACTERISTICS FORTHEPROCESS
FACILITY CRITICALITY ACCIDENTS ........................................................................57
Accident Reconstruction ..................~.................................................................................57
Geometry ........................................................................................................................... 57
Material ..............................................................................................................................59
Discussion .......................................................................................................................... 59
Conclusions ....................................................................................................................... 60
Fission Y1elds..................................................................................................................... 61
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