ABSTRACT
This chapter presents the primary components and main materials of a nuclear fission reactor. Numerous secondary materials associated with the primary components may vary with different types of nuclear fission reactors. On the basis of the energy of neutrons that causes fission, general prefixes are applied to reactors. This basis represents the most fundamental distinction between reactors. Neutrons liberated in fission possess high energies, and a nuclear reaction in which a majority of fissions are produced by fast neutrons is called a fast reactor. Research reactors have actually provided the basic inputs to the development of power reactors. A great many research reactors are known and used for various purposes. The chapter describes some of the representative systems to illustrate the widely different materials and their varied suitable combinations that have given rise to various proven reactor designs and concepts. The reactors in service produce some 1500 TWh of electricity generated in the world.
