An Introduction to the Engineering of Fast Nuclear Reactors

Size: px

Start display at page:

Download "An Introduction to the Engineering of Fast Nuclear Reactors"

Barry Burke
5 years ago
Views:

1 An Introduction to the Engineering of Fast Nuclear Reactors This book is a resource for both graduate-level engineering students and practicing nuclear engineers who want to expand their knowledge of fast nuclear reactors, the reactors of the future. The book is a concise yet comprehensive introduction to all aspects of fast reactor engineering. It covers topics including neutron physics, neutron flux spectra, Doppler and coolant temperature coefficients, the performance of ceramic and metal fuels under irradiation, the effects of irradiation and corrosion on structural materials, heat transfer in the reactor core and its effect on core design, coolants including sodium and lead-bismuth alloy, coolant circuits, pumps, heat exchangers and steam generators, and plant control. The final chapter covers all aspects of safety including operational safety and hypothetical accidents. The book includes discussions of gas coolants, the use of reactors to consume radioactive waste, and accelerator-driven subcritical systems. has more than 40 years experience in nuclear engineering, including managing the operation of a fast reactor power station and a period as Chief Technologist for Fast Reactors during which he was responsible for the entire UK national fast reactor R&D program. He spent periods at the Argonne National Laboratory (United States) and at the University of Cambridge Engineering Department. In addition to his research publications and presentations, he is the author of Fast Breeder Reactors: An Engineering Introduction.

3 AN INTRODUCTION TO THE ENGINEERING OF FAST NUCLEAR REACTORS

4 32 Avenue of the Americas, New York, NY , USA Cambridge University Press is part of the University of Cambridge. It furthers the University s mission by disseminating knowledge in the pursuit of education, learning, and research at the highest international levels of excellence. Information on this title: / C 2014 This publication is in copyright. Subject to statutory exception and to the provisions of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press. First published 2014 Printed in the United States of America A catalog record for this publication is available from the British Library. Library of Congress Cataloging in Publication data Judd, A. M. An introduction to the engineering of fast nuclear reactors /. pages cm. A revision and extension of Fast breeder reactors : an engineering introduction, published in 1981 Preface. Includes bibliographical references and index. ISBN (hardback) 1. Fast reactors. 2. Breeder reactors. 3. Nuclear engineering. I. Judd, A. M. Fast breeder reactors. II. Title. TK9203.F3J dc ISBN Hardback Cambridge University Press has no responsibility for the persistence or accuracy of URLs for external or third-party Internet Web sites referred to in this publication and does not guarantee that any content on such Web sites is, or will remain, accurate or appropriate.

5 CONTENTS Preface xi Introduction...1 What Fast Reactors Can Do 1 Chain Reactions 1 Breeding and Consumption 2 Energy Resources 6 How Fast Reactors Have Been Developed 8 The Early Years 8 The Era of Metal Fuel 10 The Importance of Burnup 11 Oxide Fuel and Sodium Coolant 13 The Period of Decline 14 The 21st Century 15 General References 16 1 Physics Introduction Physics and Design Comparison with Thermal Reactors Typical Reactors Calculation Methods The Transport Equation Discretisation The Diffusion Approximation Multigroup Diffusion Theory Fundamental Mode Calculations Perturbation Theory Matrix Notation 32 v

6 vi Contents Resonances the Effect of Temperature Resonances Effective Cross Sections Computation Transport and Diffusion Theory Computation the Monte Carlo Method Accuracy and Experimental Checks Neutron Flux Energy Spectra Power Distribution and Enrichment Zones Higher Actinides Formation of Higher Actinides Breeding Internal Breeding Fuel Composition Control Rods Materials Reactivity Worth Reactivity Requirements Reactivity Coefficients Effects of Temperature Structure Temperatures Bowing Coolant Density Doppler Coefficient Power and Temperature Coefficients Dependence of Doppler and Sodium Coefficients on Design Breeders Dependence of Doppler and Sodium Coefficients on Design Consumers Subcritical Reactors Neutron Economy Gain Changes in Reactivity Power Density 89 References for Chapter Fuel Introduction Oxide Fuel Temperatures Temperature Distribution Thermal Conductivity Conductance between Fuel and Cladding 97

7 Contents vii 2.3 Design and Manufacture of Oxide Fuel Porosity, Swelling and Smear Density Manufacturing Processes Reprocessing Stoichiometry and Oxygen Potential Fission-Product Gas Release Sealed or Vented Fuel Fuel Element Design Irradiation Behaviour of Oxide Fuel Recrystallisation Cracking Thermal and Irradiation Creep Interaction between Fuel and Cladding Migration of Plutonium and Oxygen Fission-Product Behaviour Corrosion of the Cladding Metal Fuel Temperatures Swelling Mechanical Behaviour during Irradiation Redistribution of Alloy Components Corrosion of the Cladding Reprocessing and Fabrication Other Fuel Materials Carbide Nitride Fuel for Consumer Reactors Consumption of Plutonium Consumption of Higher Actinides Ceramic Fuel Preferred Ceramic Fuel Materials for a Consumer of Higher Actinides Consumption of Higher Actinides Metal Fuel 147 References for Chapter ReactorCore Introduction Heat Transfer and Transport Fuel Element Rating Distribution of Power Density Heat Transport from the Core 153

8 viii Contents Heat Transfer to the Coolant Coolant and Cladding Temperatures Structural Materials Displacement of Atoms Irradiation Swelling Irradiation Creep, Embrittlement and Hardening Corrosion in Sodium Corrosion in Lead and Lead-Bismuth Eutectic Choice of Structural Materials Core Structure Fuel Subassemblies Subassembly Bowing and Restraint Diagrid Configuration of the Reactor Core 188 References for Chapter CoolantCircuitsandSteamPlant Introduction Choice of Coolant Sodium Coolant Primary Sodium Circuit Pool or Loop Layout Pumps Intermediate Heat Exchangers Thermal Shock High-Cycle Fatigue ( Thermal Striping ) Crack Initiation and Growth Control of Impurities Monitoring of Impurities Refuelling Steam Plant Steam Generator Design Steam Generator Tube Welds Steam Generator Heat Transfer Plant Efficiency Available Energy Control Systems Normal Operation Abnormal Conditions 235 References for Chapter 4 237

9 Contents ix 5 Safety Introduction Safety and Design Comparison with Thermal Reactors Low-Pressure Coolants Reactor Protective Systems Automatic Shutdown Whole-Core Instrumentation Subassembly Instrumentation Decay-Heat Removal Containment Operational Safety Operator Dose Sodium Fires Sodium-Water Reactions Hypothetical Accidents Accident Sequences Subassembly Accidents Whole-Core Accidents Core-Disruptive Accidents the Initiation Phase Core-Disruptive Accidents the Transition Phase Core-Disruptive Accidents Passive Protection Post-Accident Cooling 280 References for Chapter Index 285

11 PREFACE This book is a revision and extension of Fast Breeder Reactors: An Engineering Introduction, published in I have rewritten much of it in the light of developments in fast reactor technology that have taken place in the subsequent three decades, and to take account of the new applications for fast reactors that have been suggested. It is intended for the newcomer to the study of fast reactors, either as a student or at a later stage of his or her career. It will probably be most useful to someone who already has some knowledge of nuclear reactors. There are many excellent introductory texts for the beginner in nuclear engineering but they all concentrate on thermal reactors. The purpose of this book is to provide an up-to-date account of fast reactors for those who want to take the next step. Fast reactor technology has become a wide field, so wide that it is not possible to cover all of it in depth in a single book of reasonable length. What I have attempted is to cover the whole in sufficient detail to allow the reader to understand the important features, and to provide suitable references for further study. I have gone into detail on the neutron physics because any fast reactor engineer, whether he or she is a designer, an operator or a researcher, needs to understand how the machinery works at a basic level. I have also attempted to include the results of experience, often hard-won, of operating a fast reactor power station. xi

12 xii Preface I have divided the subject matter up in chapters according to discipline. Chapter 1 about the physics of fast reactors is the most detailed and mathematical. This is to give those who have to use the numbers produced by the complex computer codes that predict reactor performance some idea of where they come from. Chapter 2 is mainly about the chemistry of fast reactor fuel. Chapters 3 and 4 are about the application of mainly conventional engineering disciplines to fast reactors so they contain less theoretical detail. In Chapter 5 I have tried to show how safety can be attained by careful attention to detail in design. The Introduction includes an explanation of the difference between fast reactors and thermal reactors and a brief summary of the history of fast reactor development. I wish to thank Argonne National Laboratory for permission to reproduce Figures 2.19, 2.22 and Many of my colleagues in the atomic energy industry have been very generous in helping me to write this book and its predecessor. They are for too numerous to mention by name. By way of thanks I wish to dedicate this account of the technology to the hundreds of engineers, scientists and technicians whose achievements made possible the success of the British Fast Reactor project, started in 1946 and abandoned prematurely in 1993.

Thermodynamics of Surfaces and Interfaces

Thermodynamics of Surfaces and Interfaces An accessible yet rigorous discussion of the thermodynamics of surfaces and interfaces, bridging the gap between textbooks and advanced literature by delivering