Nuclear Energy FIFTH EDITION Nuclear Energy An Introduction to the Concepts, Systems, and Applications of Nuclear Processes FIFTH EDITION Raymond L. Murray Nuclear Engineering Department, North Carolina State University, Raleigh, North Carolina 27695 USA To Elizabeth Preface to the Fifth Edition AT THE transition to the new millennium the future of nuclear energy looks brighter. Nuclear power plants worldwide have operated safely. Applications for extension of reactor operating licenses in the U.S. are in place and construction is continuing abroad. Uses of isotopes and radiation in applications to medicine, research, and industry continue to assure human benefit. Research and development are active in the areas of controlled fusion, accelerator uses, isotope separation, space exploration, and excess weapons material disposition. Unfortunately, progress toward solutions for the nuclear waste problem has been frustratingly slow. And there are no new orders for nuclear plants in the U.S. Controversies surround the validity of the linear no-threshold model of the effect of low-level radiation and the anticipated consequences to climate of the buildup of greenhouse gases. It is the author’s firm belief that nuclear power will be necessary in the twenty-first century, as world population continues to grow, expectations for a better life are sought, and energy demands increase. The phenomenon of the Internet is dramatically changing communication of information and knowledge, including education at all levels. This new edition of the book includes citations to sites on the World Wide Web in addition to references in the print media. The author has explored the Web extensively, searching for sites that are relevant, useful, and accurate. However, the reader must beware of sites that become outdated or vanish. Further comments on the Internet appear in the Appendix. A few new Exercises are included in the fifth edition. The diskette containing programs in BASIC for use with Computer Exercises is now available free of charge on request from the author. The author hopes that the book will continue to serve in the orientation and education of the next generation of nuclear professionals and leaders, as well as being helpful to scientists and engineers in related fields. Communication by e-mail ([email protected]) with teachers, students, and other users of the book will be most welcome. Many persons have provided valuable ideas and information. They are recognized at appropriate points in the book. The advice and assistance of Michael Forster, Cate Rickard-Barr, and Lisa Jelly of Butterworth- Heinemann was most helpful. Special thanks are due Nancy Reid Baker for vii viii Preface to the Fifth Edition vital computer support, for preparation of new artwork, and for formatting the final camera-ready copy. Finally, the author is grateful for the encouragement provided by his wife, Elizabeth Reid Murray. Raleigh, North Carolina, 2000 RAYMOND L. MURRAY Preface to the Fourth Edition WORLD EVENTS in the early 1990s have accentuated the benefits of nuclear energy. The political revolutions in Eastern Europe and the U.S.S.R. have produced welcome relief in international tensions between the superpowers, with opportunity for the West to assist in enhancement of safety of reactors. The end of the Cold War produced a “peace dividend” for the U.S. that can help in solving social and financial problems. Weapons and their production capability can be phased out, and there remain scores of contaminated facilities to deal with. Military aspects of space can now be de-emphasized, with the prospect of space exploration using nuclear propulsion and nuclear power sources. The nuclear industry has taken bold positive steps to develop new and better nuclear power reactors, while the U.S. government and states continue to attack the problem of disposal of radioactive wastes. The public appears to better recognize the need for nuclear power, but remains reluctant to accept facilities to implement it. The beneficial uses of nuclear energy continue to grow, including the application of radioisotopes and radiation to medical diagnosis, treatment, and research. Regulatory policies in the U.S. that have hampered investment in nuclear power plants have largely been resolved by congressional action. At the same time, the laws encourage competition by alternative energy sources. It is the author’s belief that nuclear power will be necessary, as world population continues to grow, as expectations for better lives for people of the world are sought, but as the limits of energy efficiency are reached and fossil fuel resources become scarce. - Leadership in the technology of a closed fuel cycle enrichment, new - reactor construction, breeding, and reprocessing has been assumed by countries such as France and Japan. In the U.S., expertise necessary to maintain and expand the nuclear option in the next century needs to be preserved and extended, as professionals leave or retire from the field. The author hopes that this book will continue to serve as a useful vehicle to orient, train, and educate the next generation of professionals and leaders. The book is expected to be helpful as well for scientists and engineers in non-nuclear but related fields. As in past editions, the level of mathematics demanded by the book is - - not excessive. A new feature Computer Exercises has been added, however, intended to enhance the appreciation of effects, trends, and ix x Preface to the Fourth Edition magnitudes. They use a set of computer programs available from the author on a non-proprietary, non-profit basis. These are written in the BASIC language or utilize a popular spreadsheet. Each type of program demands a minimum of expertise in computer programming, but permits calculations that go well beyond those possible or practical by use of a hand-held calculator. Some of the programs have convenient menus; others yield directly a set of numbers; still others give graphical displays. It would have been good to be able to provide greater opportunity for the student to do creative programming and open-ended problem solving, but that was sacrificed because there is so much to learn in a field as varied and complex as nuclear technology. The author welcomes communication with teachers and students about difficulties, errors, and suggestions for improvement of the computer programs, the exercises, and the text itself. Those kind individuals who provided helpful comments are recognized in the pertinent sections. Special thanks are due the author’s wife, Elizabeth Reid Murray, for continued encouragement and advice. Raleigh, North Carolina, 1993 RAYMOND L. MURRAY Preface to the Third Edition THE ROLE of nuclear processes in world affairs has increased significantly in the 1980s. After a brief period of uncertainty, oil has been in adequate supply, but expensive for use in generating electricity. For countries without coal resources, nuclear power is a necessity, and new plants are being built. The U.S. nuclear industry has been plagued with a combination of high construction costs and delays. The latter are attributed to actions of intervenors, to inadequate management, and to regulatory changes. No new orders for nuclear reactors have been placed, and work has been suspended on a number of plants. It appears that less than 20% of the country’s electricity will be provided by nuclear power by the year 2000. Concerns about reactor safety persist in spite of major improvements and an excellent record since TMI-2. The Chernobyl accident accentuated public fears. Concerns about waste disposal remain, even though much technical and legislative progress has been made. The threat of nuclear warfare casts a shadow over commercial nuclear power despite great differences between the two applications. Although the ban on reprocessing of spent nuclear fuel in the United States has been lifted, economic factors and uncertainty have prevented industry from taking advantage of recycling. Spent fuel will continue to accumulate at nuclear stations until federal storage facilities and repositories are decided upon. Through compacts, states will continue to seek to establish new low-level radioactive waste disposal sites. Progress on breeder reactor development in the United States was dealt a blow by the cancellation of the Clinch River Breeder Reactor Project, while the use of fusion for practical power is still well into the future. Applications of radioisotopes and nuclear radiation for beneficial purposes continue to increase, and new uses of nuclear devices in space are being investigated. Although nuclear power faces many problems, there is optimism that the next few decades will see a growing demand for reactors, to assure industrial growth with ample environmental protection. In the long - - term into the 21st century and beyond nuclear will be the only available concentrated energy source. The challenge of being prepared for that future can be met through meticulous attention to safety, through continued research and development, and with the support of a public that is adequately informed about the technology, including a fair assessment of benefits and risks. xi xii Preface to the Third Edition This book seeks to provide useful information for the student of nuclear engineering, for the scientist or engineer in a non-nuclear field, and for the technically oriented layman, each of whom is called upon to help explain nuclear energy to the public. In this new edition, Part I Basic Concepts is only slightly changed; Part II Nuclear Systems involves updating of all chapters; Part III Nuclear Energy and Man was extensively revised to reflect the march of events. The “Problems” to be solved by the reader are now called “Exercises.” Many persons provided valuable ideas and information. They are recognized at appropriate points in the book. Special thanks are due my colleague Ephraim Stam, for his thorough and critical technical review, and to my wife Elizabeth Reid Murray, for advice, for excellent editorial suggestions, and for inspiration. Raleigh, North Carolina, 1987 RAYMOND L. MURRAY