Nuclear meltdown derived from a 1967 report by a group of nuclear physicists, headed by W. K. Ergen. In the event, Lapp’s hypothetical nuclear accident was cinematically adapted as "The China Syndrome" (1979). Nuclear meltdown A nuclear meltdown (core melt accident or partial core melt) is a severe nuclear reactor accident that results in core damage from overheating. The term "nuclear meltdown" is not officially defined by the International Atomic Energy Agency or by the Nuclear Regulatory Commission. However, it has been defined to mean the accidental melting of the core of a nuclear reactor, and is in common usage a reference
Fukushima Daiichi nuclear disaster (Unit 3 Reactor) 13 March an official of the Japan Nuclear and Industrial Safety Agency (NISA) told at a news conference that the emergency cooling system of Unit 3 had failed, spurring an urgent search for a means to supply cooling water to the reactor vessel to prevent a meltdown of its reactor core. At 05:38 there was no means of adding coolant to the reactor, owing to loss of power. Work to restore power and to vent excessive pressure continued. At one point, the top three meters of the uranium/mixed oxide (MOX) fuel rods were not covered by coolant. At 07:30 JST,