Risk and Safety Analysis of Nuclear Systems E-Book

John C. Lee

• Herausgeber: John Wiley & Sons
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 740

Veröffentlichungsjahr: 2012

Beschreibung

The book has been developed in conjunction with NERS 462, a course offered every year to seniors and graduate students in the University of Michigan NERS program. The first half of the book covers the principles of risk analysis, the techniques used to develop and update a reliability data base, the reliability of multi-component systems, Markov methods used to analyze the unavailability of systems with repairs, fault trees and event trees used in probabilistic risk assessments (PRAs), and failure modes of systems. All of this material is general enough that it could be used in non-nuclear applications, although there is an emphasis placed on the analysis of nuclear systems. The second half of the book covers the safety analysis of nuclear energy systems, an analysis of major accidents and incidents that occurred in commercial nuclear plants, applications of PRA techniques to the safety analysis of nuclear power plants (focusing on a major PRA study for five nuclear power plants), practical PRA examples, and emerging techniques in the structure of dynamic event trees and fault trees that can provide a more realistic representation of complex sequences of events. The book concludes with a discussion on passive safety features of advanced nuclear energy systems under development and approaches taken for risk-informed regulations for nuclear plants.

Leseprobe

CONTENTS

Cover

Half Title page

Title page

Copyright page

Preface

Permissions and Copyrights

List of Tables

List of Figures

Chapter 1: Risk and Safety of Engineered Systems

1.1 Risk and Its perception and Acceptance

1.2 Overview of Risk and Safety Analysis

1.3 Two Historical Reactor Accidents

1.4 Definition of Risk

1.5 Reliability, Availability, Maintainability, and Safety

1.6 Organization of the Book

References

Chapter 2: Probabilities of Events

2.1 Events

2.2 Event Tree Analysis and Minimal Cut Sets

2.3 Probabilities

2.4 Time-Independent Versus Time-Dependent Probabilities

2.5 Time-Independent Probabilities

2.6 Normal Distribution

2.7 Reliability Functions

2.8 Time-Dependent Probability Distributions

2.9 Extreme-Value Probability Distributions

2.10 Probability Models for Failure Analyses

References

Exercises

Chapter 3: Reliability Data

3.1 Estimation Theory

3.2 Bayesian Updating of Data

3.3 Central Limit Theorem and Hypothesis Testing

3.4 Reliability Quantification

References

Exercises

Chapter 4: Reliability of Multiple-Component Systems

4.1 Series and Active-Parallel Systems

4.2 Systems with Standby Components

4.3 Decomposition Analysis

4.4 Signal Flow Graph Analysis

4.5 Cut Set Analysis

References

Exercises

Chapter 5: Availability And Reliability of Systems With Repair

5.1 Introduction

5.2 Markov Method

5.3 Availability Analyses

5.4 Reliability Analyses

5.5 Additional Capabilities of Markov Models

References

Exercises

Chapter 6: Probabilistic Risk Assessment

6.1 Failure Modes

6.2 Classification of Failure Events

6.3 Failure Data

6.4 Combination of Failures and Consequences

6.5 Fault Tree Analysis

6.6 Master Logic Diagram

6.7 Uncertainty and Importance Analysis

References

Exercises

Chapter 7: Computer Programs for Probabilistic Risk Assessment

7.1 Fault Tree Methodology of the SAPHIRE Code

7.2 Fault and Event Tree Evaluation with the SAPHIRE Code

7.3 Other Features of the Saphire Code

7.4 Other PRA Codes

7.5 Binary Decision Diagram Algorithm

References

Exercises

Chapter 8: Nuclear Power Plant Safety Analysis

8.1 Engineered Safety Features of Nuclear Power PLANTS

8.2 Accident Classification and General Design Goals

8.3 Design Basis Accident: Large-Break LOCA

8.4 Severe (Class 9) Accidents

8.5 Anticipated Transients Without Scram

8.6 Radiological Source and Atmospheric Dispersion

8.7 Biological Effects of Radiation Exposure

References

Exercises

Chapter 9: Major Nuclear Power Plant Accidents and Incidents

9.1 Three Mile Island Unit 2 Accident

9.2 PWR In-Vessel Accident Progression

9.3 Chernobyl Accident

9.4 Fukushima Station Accident

9.5 Salem Anticipated Transient Without Scram

9.6 Lasalle Transient Event

9.7 Davis-Besse Potential LOCA Event

References

Exercises

Chapter 10: PRA Studies of Nuclear Power Plants

10.1 WASH-1400 Reactor Safety Study

10.2 Assessment of Severe Accident Risks: NUREG-1150

10.3 Simplified PRA in the Structure of NUREG-1150

References

Exercises

Chapter 11: Passive Safety and Advanced Nuclear Energy Systems

11.1 Passive Safety Demonstration Tests at EBR-II

11.2 Safety Characteristics of Generation III+ Plants

11.3 Generation IV Nuclear Power Plants

References

Exercises

Chapter 12: Risk-Informed Regulations and Reliability-Centered Maintenance

12.1 Risk Measures for Nuclear Plant Regulations

12.2 Reliability-Centered Maintenance

References

Exercises

Chapter 13: Dynamic Event Tree Analysis

13.1 Basic Features of Dynamic Event Tree Analysis

13.2 Continuous Event Tree Formulation

13.3 Cell-To-Cell Mapping for Parameter Estimation

13.4 Diagnosis of Component Degradations

References

Exercises

Appendix A: Reactor Radiological Sources

A.1 Fission Product Inventory and Decay Heat

A.2 Health Effects of Radiation Exposure

References

Appendix B: Some Special Mathematical Functions

B.1 Gamma Function

B.2 Error Function

References

Appendix C: Some Failure Rate Data

Appendix D: Linear Kalman Filter Algorithm

References

Answers to Selected Exercises

Index

Risk and Safety Analysis of Nuclear Systems

Copyright © 2011 by John Wiley & Sons, Inc. All rights reserved.

Published by John Wiley & Sons, Inc., Hoboken, New Jersey.

Published simultaneously in Canada.

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Library of Congress Cataloging-in-Publication Data:

Lee, John C, 1941–author. Risk and Safety Analysis of Nuclear Systems/John C. Lee, Norman J. McCormick. p. cm ISBN 978-0-470-90756-6 (hardback) 1. Nuclear facilities—Security measures. 2. Nuclear engineering—Safety measures. 3. Nuclear engineering—Risk assessment. I. McCormick, Norman J., 1938–author. II. Title. TK9152.L44 2011 621.48’35—dc222010049603

oBook ISBN: 978-1-118-4346-2 ePDF ISBN: 978-1-118-04344-8 ePub ISBN: 978-1-118-04345-5

PREFACE

Nuclear power provides over 20% of the U. S. electricity generation and in several other countries the percentage is much higher (e.g., in France it is nearly 80%). After a multi-decade hiatus, it appears that nuclear power again may become a viable option for new electrical generation facilities in the United States. Enrollments in undergraduate and graduate nuclear science and engineering programs around the country are now increasing and recently there have been applications to the U. S. Nuclear Regulatory Commission for the licensing of proposed nuclear power plants. We hope that this book will help enhance the safety, reliability, and availability of nuclear energy systems in the coming decades and serve to remind the next generation of nuclear professionals that a nuclear accident anywhere is a nuclear accident everywhere. This was demonstrated with the tsunami-initiated events of March 2011 at the Fukushima Daiichi nuclear complex.

The first part of the book covers the principles of risk and reliability analysis found in courses typically offered in mechanical engineering or industrial engineering departments, as well as in nuclear engineering programs. The second part of the book covers applications of the methods for probabilistic risk assessment of complex engineered systems, together with deterministic safety analysis of nuclear power plants. A review of major accidents and incidents for nuclear power plants over the past thirty years also is presented, as well as passive safety features of advanced nuclear systems under development. The advanced systems are expected to efficiently generate electricity and process heat as well as transmute transuranics from used nuclear fuel.

The book has been developed in conjunction with a course taught every year to seniors and beginning graduate students in the Nuclear Engineering and Radiological Sciences department at the University of Michigan by the first author. A portion of that course was based on the textbook Reliability and Risk Analysis Methods and Nuclear Power Applications (Academic, 1981) by the second author that was used a couple of decades ago for a course in the University of Washington Nuclear Engineering department. Portions of that book have been extensively revised and additional exercises have been included to form the first part of this book.

The first author acknowledges help from Josh Hartz and Kwang Il Ahn, and a number of his current and former students, especially John Lehning, Douglas Fynan, Athi Varuttamasenni, Fariz Abdul Rahman, and Nick Touran. He also wishes to thank the late Professor Thomas H. Pigford for an introduction to the emerging field of nuclear reactor safety and the late Professor William Kerr for sustained opportunities to learn the reactor safety culture. Finally, he offers thanks to his wife Theresa and daughter Nina for all their loving care and sustained support. The second author thanks his wife Millie for her patience and not asking too frequently “Are you sure you want to be doing this when retired?”

March 2011

John C. LeeAnn Arbor, Michigan

Norman J. McCormickSeattle, Washington

PERMISSIONS AND COPYRIGHTS

Many figures and tables in this book have been reproduced from copyrighted sources. Permission from the publishers and authors for the use of the material is gratefully acknowledged. Some of the sources are directly identified in captions and footnotes, while many others are cited by alphanumeric references. Citations for these sources are listed below:

Introduction to Nuclear Power, 2nd ed., G. F. Hewitt and J. G. CollierCopyright © 2000 by Taylor & Francis. Figures 8.13, 8.14, 8.15, 8.16, 8.17, 8.18, 8.19.

Handbook of System and Product Safety, 1st ed., pp. 242, 243, 245, W. HammerCopyright © 1972 by Pearson Education, Inc., Upper Saddle River, NJ. Figures 6.3, 6.4, 6.5.

Nuclear Engineering and DesignCopyright © 1987 by Elsevier Science and Technology. Figures 8.20, 8.21, 11.1, 11.5, 11.6.

Nuclear Engineering InternationalCopyright © 2002 by Progressive Media Group. Figure 11.9.

Nuclear NewsCopyright © 1986 by the American Nuclear Society, La Grange Park, IL. Figure 9.8.

Nuclear Science and EngineeringCopyright © 1981, 1987, 2006 by the American Nuclear Society, La Grange Park, IL. Figures 13.1, 9.15, 13.4, 13.9, 13.10, 13.11, 13.12, 13.13, Table 13.2.

Nuclear TechnologyCopyright © 1989 by the American Nuclear Society, La Grange Park, IL. Figures 9.1, 9.2, 9.4, 9.5, 9.6, 9.7.

Reliability Engineering and System SafetyCopyright © 1988, 1993, 2008 by Elsevier Science and Technology. Table 13.1. Figures 7.4, 9.1, 9.2, 13.2, 13.6, 13.7, 13.8.

The New York Times, K. ChangCopyright © June 8, 2003 by The New York Times. All rights reserved. Used by permission and protected by the copyright laws of the United States. The printing, copying, redistribution, or retransmission of the material without express written permission is prohibited. Figure 9.11.

A number of figures and tables were also obtained from publications of various government agencies and laboratories: Tables 6.1, 6.4, 6.5, 6.7, 9.1, 9.2, 10.1, 10.2, 10.3, 10.4, 10.5. Figures 2.2, 2.4, 6.8, 7.1, 7.2, 7.3, 8.1, 8.3, 8.4, 8.6, 8.7, 8.8, 8.9, 8.12, 8.26, 8.27, 8.28, 8.29, 9.3, 9.9, 9.10, 9.12, 9.13, 9.16, 9.17, 9.18, 9.19, 10.1, 10.2, 10.3, 10.510.6, 10.7, 10.8, 10.10, 10.11, 10.12, 10.13, 10.14, 10.15, 10.16, 10.17, 10.18, 10.19, 11.11, 11.12, 11.13, 11.19, 11.22, 11.23, 12.1, 12.2.

List of Tables

1.1 Factors affecting acceptance of risks

2.1 Boolean algebra for events

2.2 Results for Example 2.4

2.3 Confidence levels for mean of normal distribution

2.4 Summary of Equations for λ(t), R(t), F(t), and f(t)

2.5 Summary of Equations for , and

2.6 Classification scheme for extreme-value distributions

3.1 Moment estimators for failure probability distributions

3.2 Maximum likelihood and maximum entropy estimators

3.3 Comparison of results from Examples 3.1, 3.3, and 3.5

3.4 Upper bound estimates for failure rate given three failures observed

3.5 Diameters of rivet heads for Exercise 3.1

4.1 Fail-danger and fail-safe functional states and probabilities

4.2 Other cut sets for Example 4.9

5.1 Availability of systems consisting of identical components

5.2 Reliability of systems consisting of identical components

5.3 MTTF of systems consisting of identical components

5.4 MTTF versus Rsw

6.1 Failure modes used in Reactor Safety Study

6.2 Some generic failure modes

6.3 Examples of contributing events to common cause failures

6.4 Some generic beta factors for various reactor components

6.5 Severity classification scheme for failure modes

6.6 Sample column headings for FMECA spreadsheet

6.7 Sample classification system for FMECA

6.8 Sample guide words for HAZOPS or other analysis methods

6.9 Fault tree symbols commonly used

6.10 Fault tree construction guidelines

9.1 In-vessel accident progression stages

9.2 Release of radionuclides and fuel in the Chernobyl accident

10.1 Key to PWR accident sequence symbols

10.2 Key to BWR accident sequence symbols

10.3 PWR dominant accident sequences

10.4 Surry equilibrium mass inventory

10.5 Surry core melt inventory at vessel failure

11.1 Representative feedback coefficients and temperature rises

11.2 Design parameters for a typical SFR design

13.1 Time evolution of one possible dryout scenario

13.2 Attributes of feasible component hypotheses

A.1 Activity of radionuclides at a 3560-MWt reactor

C.1 Summary of failure rate and owntime for electrical equipment

CHAPTER 1

RISK AND SAFETY OF ENGINEERED SYSTEMS

1.1 RISK AND ITS PERCEPTION AND ACCEPTANCE

Risk and safety concerns for the engineering of nuclear power plants are somewhat analogous to the opposing yin and yang energies that represent the ancient Chinese understanding of how things work. The outer circle represents “everything”, while the “yin” (black) and “yang” (white) shapes within the circle represent the interaction of two energies that cause everything to happen. As such, risk (yin) is the performance downside of a nuclear system and safety (yang) is what happens when the system performs its intended function. In the Chinese interpretation of yin-yang, there is a continuous movement between the two energies, just as there is when a nuclear system operates. Just as the Chinese have observed, risk and safety are intertwined, even though the engineering principles for each have a different emphasis.

Risk is the combination of the predicted frequency of an undesired initiating event and the predicted damage such an event might cause if the ensuing follow-up events were to occur. In essence, it combines the concepts of “How often?” with “How bad?”

In this book we are concerned with probabilistic risk assessment (PRA) and the methods used to analyze the safety of nuclear systems. For this reason we are investigating risks that might occur to society as a whole, rather than risks that might be incurred by an individual in society. A PRA typically models events that only very rarely occur. Hence it differs from an investigation in which there is an operating history from which to predict risks. Although most of the licensing and regulations governing the current generation of operating nuclear power plants are based on deterministic assessment of the consequences of postulated accidents and operating conditions, there is an increasing emphasis placed on implementing PRA techniques in licensing decisions. With this perspective, the terminology probabilistic safety analysis often is used to represent the safe assessment that combines the elements of both probabilistic and deterministic methods. Thus, the dichotomy between risk and safety has become somewhat fuzzy in recent years.

When thinking about a complex technology it is not difficult to conjecture a series of questions: What if undesired event A happened? Or if undesired event B happened? Or if undesired event C happened? … To scientifically answer such questions requires clearly defining what the consequences of events A, B, C, … are, but an often overlooked aspect is the frequency of occurrence of such events. Risk analysis techniques are needed to assess both the frequency and the consequence of an undesired event while safety analysis techniques are for preventing the occurrence of such events.

Perception of the risk associated with any human activity, including that associated with the utilization of man-made systems, is quite subjective. This can be illustrated by the way the news media typically report on airplane crashes involving the injury or death of even a few passengers and crew, while the annual casualties of 40,000 to 50,000 individuals due to automobile accidents in the United States do not receive special coverage. The distinction between perhaps a few hundred casualties resulting from airplane accidents and a much larger number of deaths from automobile accidents in the United States every year can be characterized in two ways: (a) voluntary versus involuntary risks and (b) distributed versus acute or catastrophic risks. We consider the risk associated with traveling in private automobiles a voluntary one that is under our personal control, in contrast to the involuntary risk involved with commercial airline flights in which we do not have control. Similarly, an automobile-related accident typically does not result in a large number of casualties so the risk is distributed, while a catastrophic airline crash can result in a large number of casualties.