Guidebook on Spent Fuel Storage Options and Systems

Guidebook on Spent Fuel

Storage Options and Systems

Third Edition

TECHNICAL REPORTS SERIES No. 240

Guidebook on Spent Fuel

Storage Options and Systems

Third Edition

INTERNATIONAL ATOMIC ENERGY AGENCY

VIENNA, 2024

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Printed by the IAEA in Austria

February 2024

STI/DOC/010/240/3

IAEA Library Cataloguing in Publication Data

Names: International Atomic Energy Agency.

Title: Guidebook on spent fuel storage options and systems, third edition / International Atomic Energy Agency.

Description: Vienna : International Atomic Energy Agency, 2024. | Series: Technical Report Series, ISSN 0074-1914 ; no. 240 | Includes bibliographical references.

Identifiers: IAEAL 23-01602 | ISBN 978–92–0–135523–2 (paperback : alk. paper) | ISBN 978–92–0–135623–9 (pdf) | ISBN 978–92–0–135723–6 (epub)

Subjects: Spent reactor fuels — Storage. | Spent reactor fuels — Storage —Equipment and supplies. | Radioactive wastes — Storage. | Radioactive wastes — Management.

Classification: UDC 621.039.74 | STI/DOC/010/240/3

FOREWORD

Nuclear power can help to address the twin challenges of ensuring reliable energy supplies and curbing greenhouse emissions. The nuclear power reactors in operation today supply more than 10% of the world’s total electricity and a third of all low carbon power. Nuclear power will continue to play a key role in the world’s low carbon energy mix for decades to come. Since the inception of nuclear power, spent fuel has been generated and spent fuel storage has been a necessary step in all spent fuel management strategies. Since the 1950s, spent fuel has been stored safely and securely in a variety of wet and dry storage systems, with around 70% of the global inventory currently in storage pending decisions or implementation of decisions on its management and disposition.

In recent decades, the operating environment of nuclear power plants has continued to move toward increasing fuel cycle efficiencies through generally higher fuel burnup, which puts greater demand on the adopted spent fuel management strategy and on spent fuel storage systems. In addition, the duration of spent fuel storage is not currently defined in some instances, partly due to the long lead time to develop a deep geological repository, which subsequently impacts the handling and transportation of spent fuel in the long term.

This Technical Report is the third edition of the Guidebook on Spent Fuel Storage; earlier editions were published in 1984 and 1991. It aims at providing guidance to Member States on spent fuel storage options, describing the history and observed trends of spent fuel storage technologies, gathering operational experiences and lessons learned, observing the evolving aspects related to higher burnup and mixed oxide spent fuel and the extension of the storage time frames. It also includes information on the distribution of the current global inventory of spent fuel by storage systems and a description and terminology of available spent fuel storage technologies and different storage facility locations.

This information will enable Member States to prepare for and manage spent fuel storage issues and challenges, especially those countries embarking on nuclear power, to make the best sustainable decisions in managing their spent fuel.

The IAEA wishes to express its appreciation to everyone who took part in the preparation and review of this publication. The IAEA officer responsible for this publication was A. González-Espartero 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.

This publication does not address questions of responsibility, legal or otherwise, for acts or omissions on the part of any person.

Guidance and recommendations provided here, describing good practices, represents expert opinion but does not constitute recommendations made on the basis of a consensus of Member States.

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.

The IAEA has no responsibility for the persistence or accuracy of URLs for external or third party Internet web sites referred to in this book and does not guarantee that any content on such web sites is, or will remain, accurate or appropriate.

The authoritative versions of the publications are the hard copies issued and available as PDFs on www.iaea.org/publications.To create the versions for e-readers, certain changes have been made, including the movement of some figures and tables.

CONTENTS

1. INTRODUCTION

1.1. Background

1.2. Objective

1.3. Scope

1.4. Structure

2. SPENT FUEL STORAGE

2.1. Spent fuel arisings

2.2. Alternatives for spent fuel storage

2.3. Selection criteria for away from reactor storage

3. SPENT FUEL STORAGE TECHNOLOGIES

3.1. Wet storage

3.2. Dry storage

5. IMPACT OF AGEING ON SPENT FUEL AND SPENT FUEL STORAGE SYSTEMS

4. SAFETY

4.1. Generic spent fuel storage design safety considerations

4.2. Specific spent fuel storage design safety considerations

4.3. Safety assessment

5.1. Potential degradation mechanisms affecting storage systems and spent fuel

5.2. Surveillance

5.3. Maintenance and repair

5.4. Data preservation

6. SPENT FUEL TRANSPORTATION: CONSIDERATIONS ASSOCIATED WITH SPENT FUEL STORAGE

6.1. Transport for storage only systems

6.2. Transport for dual purpose systems

7. SECURITY AND SAFEGUARDS ASPECTS

7.1. Security and physical protection

7.2. Safeguards and accountancy

8. ECONOMICS OF SPENT FUEL STORAGE

8.1. Cost categories and components

8.2. Factors affecting costs and economics

8.3. Financing

9. ANTICIPATED FUTURE DEVELOPMENTS IN STORAGE

Appendix I: EXAMPLES OF RECENT STORAGE FACILITY DESIGNS

Appendix II: REGULATIONS AND GUIDANCE FOR SPENT FUEL STORAGE AND TRANSPORT

Appendix III: EXAMPLES OF DESIGN BASIS ACCIDENTS RELATED TO SPENT FUEL HANDLING

Appendix IV: REPORTED MATERIALS PERFORMANCE DATA

Appendix V: SPENT FUEL STORAGE RELATED IAEA PUBLICATIONS

REFERENCES

GLOSSARY

ABBREVIATIONS

CONTRIBUTORS TO DRAFTING AND REVIEW

1. INTRODUCTION

1.1. Background

Spent nuclear fuel (SNF) storage is a necessary step in any spent fuel management strategy. Around 70% of the spent fuel generated by nuclear power plants (NPPs) worldwide is accumulating in storage, pending decisions or implementation of decisions on spent fuel for recycling¹ or disposal. Although in recent years there has been a slight decrease in the amount of SNF being generated due to a combination of the more efficient use of nuclear fuel in the reactors and a number of NPPs shutting down, spent fuel generation still far exceeds existing and near future reprocessing and disposal capacities. Due to the demand for clean energy and the positive ratio of the number of new connections and reactors under construction² to those permanently shut down, the trend of spent fuel accumulating in storage is set to continue. The resulting uncertainties relative to the duration of the storage period and the amount of spent fuel in storage for the next decades create new considerations to be taken into account during the design and operation of spent fuel storage facilities.

During the first two decades of the 2000s, the NPP operating environment continued to move in the direction of ever increasing fuel cycle efficiencies, in particular through higher fuel burnups and other approaches to increase fuel efficiency which generally require increased fuel enrichment. Such developments reduce the amount of spent fuel relative to the energy being produced but put greater demands on the adopted spent fuel management strategy and on spent fuel storage systems. As higher burnup fuel produces greater decay heat, recent loss of cooling assessments in some countries have led to a drive to reduce stocks of spent fuel held in at-reactor (AR) storage facilities in order to increase safety margins. This, coupled with a saturation of AR storage capacities (as a result of NPP life extensions, delays to the implementation of back end steps or delays in achieving approval for higher density storage) has led to increasing need for additional storage capacity through away from reactor (AFR) storage facilities. At the same time, many of the first storage facilities in operation are reaching the end of their initial licence period and are undergoing a process of renewal, with some renewals already completed.

Over the 2020s, the nuclear power community looks to welcome a number of new reactors built in embarking countries.³ The sharing of operating experience, lessons learned and advice is essential for these countries to make the best sustainable decisions in managing their spent fuel.

The responsibility for establishing and implementing the overall strategy for the management of radioactive waste from NPPs is allocated to the operator [1]. The IAEA’s Specific Safety Guide SSG-15, Storage of Spent Nuclear Fuel [2], describes these responsibilities in relation to spent fuel, including determining the overall strategy for its management. Development of this strategy needs to take into account the national radioactive waste management policy, interdependences among all steps in waste management and the available options [1]. To discharge this responsibility, it is important to have the latest information on the options available for managing spent fuel. The present publication provides an updated overview and technical information on spent fuel storage options.

1.2. Objective

The overall objective of this publication is to provide guidance to Member States on SNF storage options. This is approached by providing an update to the Guidebook on Spent Fuel Storage (IAEA-TRS-240) published in 1991 [3], describing the history and observed trends of spent fuel storage options and gathering operational experiences and lessons learned. The evolving aspects related to higher burnup and mixed oxide (MOX) spent fuel and the extension of the storage time frames are also covered.

This enables Member States to better prepare for and manage spent fuel storage issues and challenges.

Guidance and recommendations provided here in relation to identified good practices represent expert opinion but are not made on the basis of a consensus of all Member States.

1.3. Scope

This guide is limited to storage of SNF from commercial power reactors. Storage of SNF from research and prototype reactors is not specifically covered here, although the storage technologies described may also be applicable for these spent fuels.

Inventory data within this publication has been taken from the country reports provided for the Seventh Review Meeting of the Contracting Parties to the Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management (Joint Convention) with a reporting date of 31 December 2019, unless other data was publicly available. Values used in the figures have been rounded, as those are intended to illustrate trends rather than displaying exact inventories.

The inventory data presented have been split into the following regions:

—