Nuclear energy or atomic energy is the type of energy that comes from the nuclei of atoms. Both protons (positive electric charge) and neutrons(neutral) are found in the nucleus of an atom. The nucleus contains most of the mass of an atom. Energy is released any time there is a change in an atom’s nucleus. There are two types of nuclear change, nuclear fission and nuclear fusion. In nuclear fission, atoms having a large mass, like uranium, are split into two and energy is released. New elements are formed as a result of nuclear fission. As a reminder, mass refers to the amount of matter found within an object. During nuclear fission, the splitting of the nucleus results in a loss of mass. The two new nuclei, that have formed as a result of the division, together have less mass than the original nucleus. The missing matter has been converted into energy. Uranium 235 is an isotope that is used in starting nuclear fission chain reactions. An isotope is a form of an element with a different number of neutrons in its nucleus.: Uranium 235 is split in two by a neutron. At releases energy and neutrons. These neutrons that are released will then split other atoms. Enough uranium, a chain reaction will begin. Each uranium 235 atom will be split and send off neutrons that will split other uranium 235 atoms If this chain reaction is controlled, like in a reactor, nuclear energy can be produced. This is also the type of chain reaction that resulted in the atomic bomb. Uranium 235 is not the only isotope used in starting nuclear fission chain reactions, but is a widely used form. Plutonium-239 is also used but many opponents of nuclear energy fear that plutonium is too dangerous. Plutonium is poisonous but remains in fuel pellets until it’s carefully removed from the plant. There has been no reported public damage from plutonium. Other materials are found in a reactor, like uranium-238. U-238 can change into a fuel that can start a fission reaction by absorbing neutrons from a U-235 fission reaction. Atoms having a small mass, like hydrogen, are involved in nuclear fusion. Nuclear fusion occurs when and new elements are formed. Nuclear fusion has the capability of releasing greater amounts of energy than nuclear fission. These fusion reactions are also referred to as thermonuclear reactions. An example of thermonuclear reactions is found on the sun where hydrogen atoms unite and form a new element, helium. This type of reaction releases heat, radiation, and light. Another example of a thermonuclear reaction is the hydrogen bomb. The atomic bomb (fission chain reaction) although very destructive is yield of energy released by a hydrogen bomb (fusion reaction). Nuclear fusion appears to be a better energy source and consumer-wise. The main problem is the control of a nuclear fusion reaction. Once that is achieved, there then would be the time needed to set up an energy plant to supply a large number of the population. The research behind nuclear fusion power and the possible fusion plant construction would take many years. “It may well be 2020, then, before we arc a fusion society. It would be wise to conserve oil supplies and to substitute other energy sources hot springs, and so on: To keep us going until fusion can take over.”1 This last statement reflects some of the present problems with nuclear energy production. Also this statement presents the various energy alternatives that are offered to us. It is important to stress here, that nuclear energy is part of our future, along with the other energy alternatives and collectively we can combat and possibly deplete our emphasis on foreign oil. B. Nuclear Power Plants Electricity in power plants I~ produced when a turbine is forced to turn. The turbine then spins a generator which produces the electricity. Water, gas, or steam can cause the blades of the turbine to spin. Steam can be produced in oil, coal, and nuclear power plants. The main difference between coal or oil power plants and nuclear plants is that coal and oil are burned in a furnace producing enough heat to change water into steam. A reactor replaces a furnace in a nuclear power plant. The reactor contains the ‘fuel’, usually uranium. The splitting (fission) of uranium produces the heat needed to change the water to steam. There are different types of nuclear power plants, but the major parts of a plant are generally the same. Within the reactor, fission occurs and energy, in the form of heat is released. This heat boils the water and steam is produced. The steam moves to the turbine that spins the generator which produces electricity. The ‘used’ steam then moves to the condenser where it changes back to water and returns through a pump to the reactor. In Connecticut, we have two types of nuclear power plants: Pressurized water reactor and boiling water reactor. The chief difference is that the pressurized water reactor has a separate steam generator and pressurizer. The pressurizer keeps heated water then moves it to the steam generator where the water is converted to steam. Also in a pressurized water reactor, the pump returns the water to the steam generator for reuse. The main parts of a nuclear reactor where the chain reactions are controlled are: (a) the fuel, like uranium 235, that undergoes fission (b) Neutrons produced by the nuclear fission reaction are slowed down by a moderator. (c) Control rods—have the ability to absorb neutrons that are released by nuclear fission. The control rods are placed in the reactor to stop nuclear fission and are removed when the fission chain reaction is needed. (d) A coolant is used to move the heat away from the fission reaction. (e) the inner containment structure or shielding to help prevent any radiation leakage. This is reinforced by a concrete building that houses the reactor. There are different types of reactors. Two, the pressurized water reactor and boiling water reactor, have been described briefly above. Another type of reactor that is in use in parts of Europe and in Russia is the breeder reactor. A breeder reactor was used in this country in 1951 to produce electricity from the first nuclear reactor plant. But, America has no breeder reactors in operation today. One is presently under development: The Clinch River Breeder Reactor Plant in Oak Ridge, Tennessee. A breeder reactor produces both electric power and fuel. Every reaction releases two or three neutrons, and only one is needed to continue the fission chain reaction. The other neutron(s) strike other atoms that are converted to fuel. Breeders are necessary for a nuclear future because the fuel supply for nonbreeders is limited, but the breeder produces more fuel than it needs. A breeder reactor plant has an estimated fuel supply of thousands of years. The opponents of breeder reactors argue many of the same ideals of the following statement: “But breeders convert uranium to plutonium reactor fuel, only a few pounds of which are needed to make a powerful bomb. Many fear nuclear weapons proliferation, and breeder development is stalled in the U.S..”2
