Dr. Samuel Glasstone, the senior author of the previous editions of this book, was anxious to live until his ninetieth birthday, but passed away in 1986, a few months short of this milestone. I am grateful for the many years of stimulation received during our association, and in preparing this edition have attempted to maintain his approach.

Previous editions of this book were intended to serve as a text for students and a reference for practicing engineers. Emphasis was given to the broad perspective, particularly for topics important to reactor design and oper­ation, with basic coverage provided in such supporting areas as neutronics, thermal-hydraulics, and materials. This, the Fourth Edition, was prepared with these same general objectives in mind. However, during the past three decades, the nuclear industry and university educational programs have matured considerably, presenting some challenges in meeting the objec­tives of this book.

Nuclear power reactors have become much more complex, with an ac­companying growth in supporting technology. University programs now offer separate courses covering such basic topics as reactor physics, thermal — hydraulics, and materials. Finally, the general availability of inexpensive powerful micro — and minicomputers has transformed design and analysis procedures so that sophisticated methods are now commonly used instead of earlier, more approximate approaches.

In light of this picture, giving priority to needed perspective, even at the expense of some depth which is now available elsewhere, was considered appropriate. Also, since it was important to keep the length of the book about the same, necessary new material could only be accommodated by deleting some old material. Significant new material has been added, par­ticularly in the areas of reactor safety, fuel management, plant operations, and advanced systems. However, material that generally continues to meet the objectives of the book has been retained, both to preserve its flavor and to keep the revision effort within reasonable bounds. Also, after the passing of Dr. Glasstone, I felt it inappropriate to change the basic ap­proach of the book.

Readers of the book will want to use computer-based methods to sup­plement the text material, as appropriate. Space did not permit a mean­ingful presentation of the methodology required. All problems listed at the end of the chapters may be solved with hand calculations. Although I have continued the use of SI units, as begun in the Third Edition, complete adoption by industry has been slower than anticipated. Therefore, some problems utilize English units.

A two-volume format has been adopted for this edition to provide read­ers with some flexibility. The chapters have been rearranged somewhat to provide volume coherence, with basic material concentrated in the first volume. An Instructor’s Manual is also available for qualified instructors, to be ordered directly from the publisher.

The suggestions made by A. L. B. Ho, L. E. Hochreiter, В. K. Malaviya, V. H. Ransom, J. R. Redding, G. R. Odette, and T. G. Theofanous are gratefully acknowledged.

Thanks are due to the Chapman & Hall team that published the book, particularly Marielle Reiter for production administration and Barbara Zeiders for editorial assistance.

Finally, I wish to thank my wife for her help and encouragement during the preparation of the book.

Alexander Sesonske San Diego, California March 1994

INTRODUCTION

8.1. The availability of new, powerful digital computers in recent years has resulted not only in increased sophistication in nuclear reactor engi­neering but also in the development of other disciplines involving systems and optimal control theory. These subjects have potential applications in reactor engineering. In nuclear power plant design and operation, decisions must be made in applying engineering principles to the problems to be solved. Since plants are complex, aids to the decision-making process are essential. One aid is to recognize certain portions of the plant having a common function as a system, a term that we will explain further shortly. Decisions regarding dependencies between systems can be expedited by this type of representation.

8.2. The systems concept as a decision tool has its roots in a subject known as operations research [1], which evolved from the strategic planning needs of World War II. As powerful computers became available, sophis­ticated methods for systems analysis, modeling, and simulation were de­veloped for engineering and management applications. In this computer-
based information age, we are witnessing a trend toward greater and greater general use of such systems-related tools for decision making. Computer modeling of nuclear power plant behavior is essential for normal operation as well as for the analysis of postulated accidents to meet licensing re­quirements (§12.231 et seq.).

8.3. Space here does not permit even an introduction to operations research and modeling procedures. Reliability analysis applications will be mentioned in Chapter 12. However, we do wish to alert the reader to the possibility of using available operations research-based methods for the analysis and design of nuclear reactor systems. A first step here is to identify some typical systems.

8.4. In modern engineering practice which utilizes the power of the computer to accomplish most tasks, information of various kinds is a nec­essary tool for decision making. Nuclear engineers have available to them a variety of data bases, computer codes, and other information from many sources. An introduction to these resources is useful as a complement to the presentation of relevant reactor engineering topics in this book. Also, we have drawn attention to appropriate information sources in various other chapters.