For use as fuel in a reactor, uranium is formed into small pellets, which are stacked inside protective metal rods. Fuel rods are bundled together into fuel assemblies, which make up the reactor core. In addition to the fuel rods, there are other rods in the fuel assemblies, which are, made of a material, which can absorb the neutrons. They are called the control rods, because they are used to control the rate at which the fission reaction takes place, or to stop it altogether. When uranium atoms split, they give off radiation as well as heat.
Radiation is a natural form of energy that has always existed on earth and throughout the universe.
Although the term can include such forms of energy as light and radio waves, it usually refers to ionizing radiation. Ionizing radiation can change the chemical composition of many things, including living tissue. Therefore, we must limit our exposure to it. The following measures help ensure that nuclear powerplants in the United States are operated to protect the health and safety of workers, the public, and the environment. They are thoroughly trained and periodically retrained on operating procedures.