ABSTRACT
This chapter discusses how the uranium or plutonium that is produced from a purification, enrichment, or recycling process can be used to fabricate nuclear fuel rods and fuel assemblies. These fuel assemblies are then bundled together to construct what is known as the reactor core. In pressurized water reactors and boiling water reactors, the fuel rod diameter varies with the number of fuel pins that are used. Generally, the more fuel pins there are in a fuel assembly, the smaller the individual pins will be. The number of fuel pins per assembly is also considerably smaller, and the surrounding cans are usually made of stainless steel. As the fuel pins become irradiated, and they reach their normal operating temperature, a number of structural changes begin to occur within the fuel itself. The spread in the data is probably attributable to slight differences in the design of the fuel pins themselves.
