Corium (nuclear reactor) Corium (nuclear reactor) Corium (also called fuel containing material (FCM) or lava-like fuel containing material (LFCM)) is the lava-like mixture of fissile material created in a nuclear reactor's core during a nuclear meltdown. It consists of nuclear fuel, fission products, control rods, structural materials from the affected parts of the reactor, products of their chemical reaction with air, water and steam, and, in the event that the reactor vessel is breached, molten concrete from the floor of the reactor room. The heat causing the melting of a reactor may originate from the nuclear chain reaction, but more commonly decay heat
Nuclear reactor physics rate of the reaction. The physics of nuclear fission has several quirks that affect the design and behavior of nuclear reactors. This article presents a general overview of the physics of nuclear reactors and their behavior. In a nuclear reactor, the neutron population at any instant is a function of the rate of neutron production (due to fission processes) and the rate of neutron losses (due to non-fission absorption mechanisms and leakage from the system). When a reactor’s neutron population remains steady from one generation to the next (creating as many new neutrons as are lost), the fission chain reaction