was a catastrophic failure at the Fukushima I Nuclear Power Plant on 11 March 2011 , resulting in a meltdown of three of the plant 's six nuclear reactors .
The Fukushima nuclear disaster is a series of ongoing equipment failures , reactor meltdowns , and releases of radioactive materials at the Fukushima Daiichi Nuclear Power Plant , following the Tōhoku earthquake and tsunami on March 11 , 2011 .