Corium (nuclear reactor) from the pre-meltdown reactor or be due to spontaneous fission of reactor-created actinides. In the absence of adequate cooling, the materials inside of the reactor vessel overheat and deform as they undergo thermal expansion, and the reactor structure fails once the temperature reaches the melting point of its structural materials. The corium melt then accumulates at the bottom of the reactor vessel. In the case of adequate cooling of the corium melt, the melt can solidify and the spread of damage is limited to the reactor itself. However, corium may melt through the reactor vessel and flow out or be
Nuclear power A fission nuclear power plant is generally composed of a nuclear reactor, in which the nuclear reactions generating heat take place; a cooling system, which removes the heat from inside the reactor; a steam turbine, which transforms the heat in mechanical energy; an electric generator, which transform the mechanical energy into electrical energy. A nuclear reactor is only part of the fuel life-cycle for nuclear power. The process starts with mining (see "Uranium mining"). Uranium mines are underground, open-pit, or in-situ leach mines. In any case, the uranium ore is extracted, usually converted into a stable and compact form such