Nuclear Energy

Nuclear Energy

The fundamental source of power

In the last fifty years we have learned more about the fundamental structure of metter than in all history. Today we know that the rearrangement of the particles comprising the atom accounts for all the energy in the universe. And we are just beginning to learn how to capture and make use of some of that energy.

To illustrate this relationship between matter and energy let us consider what happens to a simple material such as carbon when it is burned. Each carbon atom, like all atoms, consists of a compact central nucleus made up of various heavy particles called nucleons, surrounded by lighter particles called electrons.

Electrons surround the nucleus in somewhat the samo manner as planets circle around the sun.

For years we were taught a fundamental rule, "Matter cannot be created or destroyed". When carbon is burned in oxygen, the weight of the carbon dioxide gas given off in the burning reaction seems to be exactly the same as that of the oxygen and carbon beforehand. The energy given off as heat was explaines as chemical energy inherent in the two materials.

Einstein introduced a new concept

Albert Einstein was the first man to offer a more satisfactory explanation for the interrelationship between matter and energy as part of his Theory of Relativity. He concluded that matter and energy were interchangeable and that the relationship between them could be expressed by the equation:

Energy = (Mass) x (Velocity of Light)²

In this key equation, the value of the velocity of light, which is always constant, is so large a very small change in mass is equivalent to an almost incredible amount of energy,

The vast amount of research preceding the first atomic bomb, as well as the bomb itself, offered dramatic proof of Einstein's Theory. If this equation is applied to the burning of one pound of carbon, we can calculate thet the heat energy given off is equivalent to only four ten-billionths of a pound, a weight loss so small that no instruments are able to detect it.

The burning of carbon is a typical example of a chemical reaction. There are countless examples of chemical reaction in our everyday lives and in industry. In all these reactions, only the outermost electrons of the atoms are disturbed. As a result, only an immeasurably small change in mass takes place, and only a relatively small amount of energy is given off.

Two kinds of nuclear reactions

In the case of nuclear reactions, the heavy nucleus of the atom is changed and far greater amounts of energy are liberated. There are two omportant kinds of nuclear reactions: nuclear fusion and nuclear fission.

In nuclear fusion two or more relatively light nuclei combine to become a single nucleus which weights less than the sum of the weights of the parent nuclei. Tremendous amounts of energy are released in this process. Temperatures in the millions of degrees are required before the fusion reaction can take place Fusion is bolieved to be the source of the sun's energy, with hydrogen nuclei continuosly combining to form helium nuclei.

The first fusion reaction initiated by man was the hydrogen bomb. Controlled fusion, when it is commercially achieved some day, may become one of the most important developments in history because it will furnish almost limitless amounts of energy from fuels that are plentiful.

The second type of reaction is nuclear fission, in which a heavy nucleus splits into two or more fragments. The total weight of all the fragments is somewhat less than the weight of the parent nucleus, and energy is released in proportion to this weight loss. The nuclei of some of the heavier metals like plutonium, and types of uranium and thorium, are especially suited to this type of reaction. In the fission of these nuclei, certain particles are ejected which cause fission of neighboring nuclei, thus sustaining the reaction.

The explosion of an atom bomb is an example of nuclear fission which is allowed to occur at very rapid rate. However, nuclear fission has already begun serving mankind in peaceful ways through power reactors. In the reactor, energy from of heat, which is used to convert water to steam. The steam turns a turbine generator which generates electricy in exactly the same way as in the conventional steam power plant.