The FUKUSHIMA DAIICHI nuclear disaster was an energy accident at the FUKUSHIMA DAIICHI Nuclear Power Plant in ŌKUMA, FUKUSHIMA Prefecture, initiated primarily by the tsunami following the TŌHOKU earthquakeon 11 March 2011.
   The disaster was the most significant nuclear incident since the 26 April 1986 CHERNOBYL disaster and the second disaster to be given the Level 7 event classification of the International Nuclear Event Scale.
   The largest tsunami wave was 13 meters high and hit 50 minutes after the initial earthquake, overwhelming the plant's seawall, which was 10 m high (i.s.).