Fukushima nuclear disaster

Major nuclear accident that began 11 March 2011 at the Fukushima Daiichi Nuclear Power Plant in Okuma, Fukushima, Japan, when the Tohoku earthquake and tsunami disabled the plant's backup power. The inability to cool the reactors after shutdown compromised containment and released radioactive contaminants; it is the worst nuclear incident since Chernobyl, rated at maximum severity on the International Nuclear Event Scale. At least 164,000 residents were displaced, and cleanup and compensation costs were estimated at 20 trillion yen, about 180 billion US dollars.