12 March 2011
On this day in 2011 the Fukushima 1 Nuclear Power Plant, Futaba District, Japan, suffered a meltdown and explosion releasing radioactive material into the environment.
On 11 March 2011 a magnitude 9.0 earthquake and tsunami struck approximately 70 kilometres east of the Oshika Peninsula off the northeast coast of Japan. Units 4, 5 and 6 had been shut down prior to the earthquake for planned maintenance.The remaining reactors were shut down automatically after the earthquake, and the remaining decay heat of the fuel was being cooled with power from emergency generators.
The tsunami generated by the undersea earthquake resulted in waves of up to 14 meters. The reactors were designed to handle up to 5.7 meters and the tsunami which hit the plant disabled emergency generators required to cool the reactors.
The events at Fukushima have been rated at Level 7 (major release of radioactive material with widespread health and environmental effects requiring implementation of planned and extended countermeasures) on the International Nuclear Event Scale.