Safe handling and storage of plutonium

147 Pages·1998·0.532 MB·English

by  International Atomic Energy Agency

SAFE HANDLING AND
STORAGE OF PLUTONIUM
The following States are Members of the International Atomic Energy Agency:
AFGHANISTAN HOLY SEE PARAGUAY
ALBANIA HUNGARY PERU
ALGERIA ICELAND PHILIPPINES
ARGENTINA INDIA POLAND
ARMENIA INDONESIA PORTUGAL
AUSTRALIA IRAN,ISLAMIC REPUBLIC OF QATAR
AUSTRIA IRAQ REPUBLIC OF MOLDOVA
BANGLADESH IRELAND ROMANIA
BELARUS ISRAEL RUSSIAN FEDERATION
BELGIUM ITALY SAUDI ARABIA
BOLIVIA JAMAICA SENEGAL
BOSNIA AND JAPAN SIERRA LEONE
HERZEGOVINA JORDAN SINGAPORE
BRAZIL KAZAKHSTAN SLOVAKIA
BULGARIA KENYA SLOVENIA
CAMBODIA KOREA,REPUBLIC OF SOUTH AFRICA
CAMEROON KUWAIT SPAIN
CANADA LATVIA SRI LANKA
CHILE LEBANON SUDAN
CHINA LIBERIA SWEDEN
COLOMBIA LIBYAN ARAB JAMAHIRIYA SWITZERLAND
COSTA RICA LIECHTENSTEIN SYRIAN ARAB REPUBLIC
COTE D’IVOIRE LITHUANIA THAILAND
CROATIA LUXEMBOURG THE FORMER YUGOSLAV
CUBA MADAGASCAR REPUBLIC OF MACEDONIA
CYPRUS MALAYSIA TUNISIA
CZECH REPUBLIC MALI TURKEY
DEMOCRATIC REPUBLIC MALTA UGANDA
OF THE CONGO MARSHALL ISLANDS UKRAINE
DENMARK MAURITIUS UNITED ARAB EMIRATES
DOMINICAN REPUBLIC MEXICO UNITED KINGDOM OF
ECUADOR MONACO GREAT BRITAIN AND
EGYPT MONGOLIA NORTHERN IRELAND
EL SALVADOR MOROCCO UNITED REPUBLIC
ESTONIA MYANMAR OF TANZANIA
ETHIOPIA NAMIBIA UNITED STATES
FINLAND NETHERLANDS OF AMERICA
FRANCE NEW ZEALAND URUGUAY
GABON NICARAGUA UZBEKISTAN
GEORGIA NIGER VENEZUELA
GERMANY NIGERIA VIET NAM
GHANA NORWAY YEMEN
GREECE PAKISTAN YUGOSLAVIA
GUATEMALA PANAMA ZAMBIA
HAITI 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’’.
© IAEA,1998
Permission to reproduce or translate the information contained in this publication may be
obtained by writing to the International Atomic Energy Agency, Wagramer Strasse 5, P.O. Box 100,
A-1400Vienna,Austria.
Printed by the IAEA in Austria
September 1998
STI/PUB/1061
SAFETY REPORTS SERIES No. 9
SAFE HANDLING AND
STORAGE OF PLUTONIUM
INTERNATIONAL ATOMIC ENERGY AGENCY
VIENNA,1998
VIC Library Cataloguing in Publication Data
Safe handling and storage of plutonium. — Vienna : International Atomic
Energy Energy,1998.
p. ; 24 cm. —(Safety reports series,ISSN 1020–6450 ;
no. 9)
STI/PUB/1061
ISBN 92–0–102998–5
Includes bibliographical references.
1. Plutonium—Safety measures. 2. Plutonium—Storage.
I.International Atomic Energy Agency. II. Series.
VICL 98–00198
FOREWORD
A large increase in the use of plutonium was anticipated with the development
of the civil applications of nuclear energy. Significant capital investments were made
in facilities to separate plutonium from spent nuclear fuel. However, with the
discoveries of large quantities of inexpensive uranium ores (which provide an
alternative to plutonium as a nuclear fuel) coupled with the slow development of
nuclear electrical energy and with the rapidly escalating cost of developing and
deploying fast breeder reactors (which were expected to be the major users of
plutonium), the utilization of separated plutonium has not kept pace with its rate of
separation. As a result, the stockpiles of separated civil plutonium around the world
totalled more than 150 t at the end of 1996.
This Safety Report updates IAEA Safety Series No. 39, ‘Safe Handling of
Plutonium’,which was published in 1974. The focus of the previous publication was
on plutonium research and development facilities,which used very limited quantities
of plutonium. At that time,the average burnup of fuel was much lower than it is today.
With higher burnup,there are higher concentrations of 238Pu,240Pu,241Pu and 242Pu.
Also,large amounts of weapon grade plutonium (with greater than 90% 239Pu) have
been declared to be in excess of military requirements,and these materials may also
be added to the civil plutonium inventories. This report therefore describes the effects
of this wide variance in isotopic composition on storage and handling requirements.
The effects of stricter standards for the exposure of personnel to radiation — which
have been established since Safety Series No. 39 was published — are also described.
That publication did not address criticality because it covered only laboratory scale
facilities (facilities which had less than 220 g of plutonium). This report, however,
describes facilities now in place or needed in the future which have large quantities
of plutonium, and thus it addresses criticality issues as well. Further, because of the
growing need to store plutonium for long periods of time, this report also covers
plutonium storage. Although safeguards and physical security are very important
issues with respect to plutonium handling and storage,these issues are not covered in
this report.
The development and publication of this report is part of an expanded
programme within the IAEA to identify and deal with problems associated with the
accumulation of stockpiles of separated civil plutonium. It is the result of a sharing of
data and experience concerning the handling and storage of plutonium by the
countries which have the most experience in these areas. The officer responsible for
this report was J. Finucane from the Nuclear Fuel Cycle and Materials Section of the
Division of Nuclear Fuel Cycle and Waste Technology.
EDITORIAL NOTE
Although great care has been taken to maintain the accuracy of information contained
in this publication, neither the IAEA nor its Member States assume any responsibility for
consequences which may arise from its use.
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. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1. Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2. Objective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.4. Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. CURRENT AND FUTURE PLUTONIUM
ACTIVITIES AND INVENTORIES . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1. Separation of civil plutonium from irradiated fuel . . . . . . . . . . . . . 5
2.2. Storage of separated civil plutonium . . . . . . . . . . . . . . . . . . . . . . . 5
2.3. Consumption of separated civil plutonium . . . . . . . . . . . . . . . . . . 6
2.4. Research and development:Emerging technologies . . . . . . . . . . . . 9
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3. NUCLEAR,PHYSICAL AND CHEMICAL PROPERTIES
OF PLUTONIUM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.1. Nuclear properties of plutonium . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.2. Physical and chemical properties of plutonium . . . . . . . . . . . . . . . 16
3.3. Chemical and radiolytic reactions . . . . . . . . . . . . . . . . . . . . . . . . . 22
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4. PLUTONIUM IN THE ENVIRONMENT . . . . . . . . . . . . . . . . . . . . . . . 25
4.1. Sources of environmental plutonium . . . . . . . . . . . . . . . . . . . . . . . 25
4.2. Distribution of plutonium in the environment . . . . . . . . . . . . . . . . 26
4.3. Behaviour of plutonium in the environment . . . . . . . . . . . . . . . . . 27
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
5. PATHWAYS TO HUMANS AND THE BIOLOGICAL EFFECTS
OF PLUTONIUM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
5.1. Internal exposure to plutonium . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
5.2. Entry of plutonium by inhalation . . . . . . . . . . . . . . . . . . . . . . . . . 35
5.3. Gastrointestinal absorption of plutonium . . . . . . . . . . . . . . . . . . . . 36
5.4. Penetration of plutonium through intact skin . . . . . . . . . . . . . . . . . 39
5.5. Distribution and retention of absorbed plutonium . . . . . . . . . . . . . 39
5.6. Reducing the dose from internally deposited plutonium . . . . . . . . 40
5.7. External exposure to plutonium . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
6. LICENSING,CONTROLS AND REGULATORY LIMITS . . . . . . . . . . 45
6.1. Licensing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
6.2. Exemption levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
6.3. Occupational dose limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
6.4. Dose limit to the public . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
6.5. Optimization of protection (ALARA) . . . . . . . . . . . . . . . . . . . . . . 48
6.6. Regulatory guides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
6.7. Criticality safety limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
7. SAFETY ASPECTS OF DESIGN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
7.1. Safety assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
7.2. Containment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
7.3. Ventilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
7.4. Fire safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
7.5. Prevention of explosions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
7.6. Criticality safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
7.7. Removal of decay heat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
7.8. Prevention of mechanical failures or load drop . . . . . . . . . . . . . . . 70
7.9. Radiation shielding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
7.10. Countermeasures for the loss of electrical power . . . . . . . . . . . . . . 71
7.11. Seismic safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
7.12. Aircraft crash hazard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
7.13. Minimization of radioactive waste . . . . . . . . . . . . . . . . . . . . . . . . 72
7.14. Design for decommissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
7.15. Feedback for safety improvements . . . . . . . . . . . . . . . . . . . . . . . . 73
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
8. OPERATIONAL SAFETY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
8.1. Effective management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
8.2. Characterization during commissioning . . . . . . . . . . . . . . . . . . . . 76
8.3. Operating procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
8.4. Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
8.5. Control of maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
8.6. Control of modifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
8.7. Audit of operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
8.8. Radiation monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
8.9. Area monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
8.10. Individual monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
8.11. Environmental monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
8.12. Operational emergency procedures . . . . . . . . . . . . . . . . . . . . . . . . 85
8.13. Examples of incidents and practical responses . . . . . . . . . . . . . . . 87
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
9. SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
9.1. Safe handling of plutonium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
9.2. Storage of plutonium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
ANNEX I. EXAMPLES OF PLUTONIUM PLANT DESIGN . . . . . . . . . . 93
I–1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
I–2. Modern glove box design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
I–3. Conversion (finishing) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
I–4. Packaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
I–5. Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
I–6. Safety principles applied to MOX fabrication . . . . . . . . . . . . . . 103
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
ANNEX II. RADIOLOGICAL SAFETY DATA FOR
PLUTONIUM HANDLING . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
II–1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
II–2. Surface gamma dose rate of PuO and MOX . . . . . . . . . . . . . . . . 110
2
II–3. Attenuation factor for plutonium gamma radiation . . . . . . . . . . . 113
II–4. Neutron yields and dose rate from plutonium . . . . . . . . . . . . . . . 113
II–5. Internal exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
II–6. Radiation exposure from criticality incidents . . . . . . . . . . . . . . . 117
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
ANNEX III. CRITICALITY SAFETY PARAMETERS . . . . . . . . . . . . . . . . 121
III–1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121