a situation in which the temperature in the reactor exceeds the melting point of the fuel
a possible situation that may occur when a nuclear reactor core gets so hot (accidentally) that the fuel rods melt and release the radioactive fission products trapped inside.
The melting of fuel in a nuclear reactor after the loss of coolant water. If a significant portion of the fuel should melt, the molten fuel could melt through the reactor vessel and release large quantities of radioactive materials into the containment building.
Melting of the core of a nuclear reactor.
Meltdown is a video game developed by Momentum Games and released December 2006. Designed to be played on handheld devices the game requires only a single button in order to play. This game is the first to feature the Momentum Games mascot Emgee, a robot who's job in Meltdown is to shutdown a series of failing nuclear reactors in order to avoid the meltdown of a power station.