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Preface
Matter is not converted to energy. The equivalence of mass and energy is involved in fundamentally the same way in chemical fuels as in nuclear fuels. The equivalence of mass and energy is neither an explanation of how these fuels release energy, nor is that equivalence even necessary in order for the release to occur.
When the complexities are stripped away, it's about bonds. Bonds are not the sole property of chemists. Bonds, whether chemical or nuclear, occur whenever a force of attraction brings two objects together and holds them there. In coming together, Work is done, and energy is released.
The nuclear force brings nuclear particles together, forming nuclear bonds, and energy is released. Along with that energy comes the mass of that energy.
Both the energy and the mass that comes with it are much greater in nuclear reactions than in chemical reactions. While the mass goes unnoticed in the chemical process, it is very much evident in the results of nuclear processes. So much so that it was in great measure the means for gaining information about nuclear reactions, which are not terribly well suited for laboratory experimentation.
On August 6, 1945, an atomic bomb small enough to fit in most living rooms, destroyed the Japanese city of Hiroshima. The reporters wanted to know how to explain this new weapon to the public. The technical people who briefed the reporters told them that because of Einstein, a way had been found to turn little tiny bits of matter into enormous amount of energy. So that's what the newspapers went with.
Nuclear science became immediately cloaked in the aura of relativity theory. The alchemy of turning tiny bits of matter into incredibly destructive energy was believed not because it was understood, but because there was a bomb, a city had been destroyed and a war concluded because of it.
At least one of the reasons that this confusing explanation was let loose, to become lodged in common wisdom and in text books, is that many otherwise competent scientists believed it. For so long had they been deriving energy predictions from mass measurements that they began themselves to think that the loss of mass caused the release of energy.
In the darkness, the cart had for all the world come to look as though it was in front of the horse.
Quite apart from failing to explain nuclear fission, the release of mass along with energy is not in the least unique to nuclear processes. It occurs wherever some source fulfils a need for energy in our world. Wherever and however we obtain a Joule of energy, there is (1 Joule/c2) of mass that comes with it, and therefore goes missing from the fuel that provided us that Joule.
It is entirely ordinary and unremarkable that it should also occur in nuclear fission.
It is the aim in this book to straighten out this confusion, because only then can readers understand the way nuclear reactions provide energy. In the process we hope to help lift the veil of mystery and mystique that has turned so many among us into aliens in a field that is as fascinating as it is important to our lives.
This book also deals at length with practical questions of nuclear technology, the design of reactors, the nature of radioactivity, and the facts behind the assessment of risks and the arguments of policy. It also treats such matters of nuclear science as the chain reaction, the theoretical origin of the instability, and the fortuitous characteristic of the fission reaction that enables us to engineer it to a condition of stability.
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Choices have to be made in preparing a book such as this that is designed for the inquisitive lay reader. These choices may leave some critics feeling that too much has been omitted or that some detail and some rigor have been slighted. It may at the same time leave other readers feeling that the goals are too ambitious, and that too much has been demanded of their capacity for abstract thinking and algebraic concepts.
With apologies to both these camps, we have decided to follow a path that has proved successful. This course of study has been a part of the author's physics course for twenty years, during which it has undergone modification and development in response to student reaction. It has required of the students nothing more in their mathematical repertoire than an introductory high school course in algebra.
We have stayed with the Force-Work-Energy model of physical events that has been replaced in the quantum domain by the Interaction model. Yet even the most sophisticated treatments of the nuclear energy question invoke binding energies based on the forces of attraction between nucleons. Although the argument could be made that this skirts some issues involved with the events in a nucleus, a much stronger argument can be made for its pedagogic value and its essential correctness.
We have chosen to add to the usual descriptions of nuclear reactor design some quantitative insight into the questions of stability and control, and to dwell at some length on the remarkable properties of exponential functions which play such a central role in the harnessing of the chain reactions in nuclear energy production. We deal in plain language with the haunting question, "Why is the taming of the nuclear reaction so impossibly precarious?" and with the obvious next question, "How can we do it anyway?" These are vital bits of science and engineering for anyone looking to understand some of the issues of risk assessment attendant to choosing an effective public policy in the nuclear field.
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It is only a short step from believing that "only the experts can understand nuclear physics," to accepting the conclusion that decisions and policies about nuclear technology can best be made by experts.
It is always bad government to leave any important public issue permanently and systematically in the hands of professionals, who, smart as they might be, have, by definition, a bias that may not be in the public interest.
Nuclear issues are life and death issues for all people on the globe. We are all at risk if decisions on such issues are based solely on the vested interest of those whose personal livelihood is involved with the very industry whose business it is to develop and build nuclear gear.
This is not to say that the views of experts and those in the industry are bound to be wrong, or that we should ignore the expertise and experience of professionals. It does say that it is vital to educate and empower a citizenry that can make its own informed judgments after listening critically to the experts.
To do otherwise is as foolish as it is, in the words of newspaper columnist Russell Baker, to leave economics to the economists.
Of course, as in most other disciplines, full and complete technological competence requires advanced study and advanced methodology. In this instance that would involve more elaborate use of mathematics and a more advanced familiarity with physics.
But a remarkably accurate and sensible understanding of the nuclear field is available to the average person willing to meet a book like this half-way. That means a commitment of reasonable time and effort, and a willingness to add and subtract and read simple algebraic language.
Beyond the practical, there is an intellectual treat in store for the reader. In gaining an understanding of the ordinariness of nuclear processes, one encounters once again that recurrent theme in basic science, the surprising commonality of fundamental ideas that span the chemical, biological, and physical world at the most elemental level. There is ultimately a single process by which fuels give up energy for our use, and this single process reaches from the burning of fossil fuels, to the generation of electric power from waterfalls, to the instantly ready energy stored in the muscle of frog, elephant, and human, and to the way in which energy is harvested from the atomic nucleus. | 
Engineering Education
