How is the uranium and radioactive material stored?
TMI Unit 1 and other nuclear plants in the U.S. were designed and built with redundant and multiple barriers to prevent the release of radioactive material into the environment. The first barrier is the fuel itself: the solid ceramic uranium pellets. During the process of fission, the uranium atoms that make up the pellets split, which creates the heat essential to turn water into steam that turns the blades of the turbine-generator. Fission creates radioactive by-products that remain locked safely inside the ceramic pellets. The pellets are sealed in metal fuel rods that are approximately 13 feet high and half an inch in diameter. Fuel rods are made of zirconium, which resists heat, radiation and corrosion. The rods are bundled together into fuel assemblies. The fuel assemblies make up the nuclear reactor core, which is about 12 feet in diameter. The reactor core is inside the reactor vessel, which has steel walls 8 inches thick. The reactor vessel sits inside a shield wall, which mad
