Sources and Resources

1.1 INTRODUCTION

This book is written from an engineer’s viewpoint, particularly that of a thermal engineer, that is, a design or research engineer concerned with heat production and utilization. We believe that the most important problems in the utilization of nuclear power concern the handling of thermal energy generated in the various processes. This includes handling under the normal operating and processing conditions and dealing with heat removal problems under the unlikely condi­tions of an accident. The problem of handling thermal energy associated with nuclear power does not stop when the fuel is removed from the power station; small amounts of heat are generated in the spent fuel before it is processed and in the waste products. The consequences of this are also the concern of the thermal engineer.

The approach that we shall take, therefore, is one that is not normally fol­lowed in general books on nuclear energy. We will follow the history of nuclear materials from their cosmic origins, through their terrestrial life span up to the time when they are used in nuclear reactors, and beyond. Although we will need to explain some elementary aspects of physics, the emphasis will be on what happens to the thermal energy.

We begin with the history of uranium in the earth, the decay of its isotopes, and the effect this decay has had on the earth as we know it. Comparisons are made with the earth’s other main energy source: the sun. Energy from the sun is derived either directly or through storage media such as fossil fuels, hydro­electric power, and winds.

The rate at which energy may be extracted from nuclear materials can be en­hanced by the self-sustaining process of nuclear fission. Nuclear fission does not normally occur in nature, but recent studies have revealed that nature an­ticipated Enrico Fermi by about 2 billion years in creating a natural nuclear fis­sion reactor by a series of extraordinary and improbable events. We shall use this example in introducing nuclear fission.

In the final part of this chapter, we compare the relative magnitudes of thermal energy resources of the various types: fossil fuel, nuclear, solar, and so forth.