The is a disabled BWR nuclear power plant located on a site in the towns of Okuma and Futaba in the Futaba District of Fukushima Prefecture, Japan. First commissioned in 1971, the plant consists of six boiling water reactors (BWR). These light water reactors drove electrical generators with a combined power of 4.7 GWe, making Fukushima Daiichi one of the 15 largest nuclear power stations in the world. Fukushima was the first nuclear plant to be designed, constructed and run in conjunction with General Electric, Boise, and Tokyo Electric Power Company (TEPCO). The plant suffered major damage from the magnitude 9.0 earthquake and tsunami that hit Japan on March 11, 2011. The incident permanently damaged several reactors making them impossible to restart. Due to the political climate, the remaining reactors will not be restarted. The disaster disabled the reactor cooling systems, leading to releases of radioactivity and triggering a 30 km evacuation zone surrounding the plant; the releases continue to this day. On April 20, 2011, the Japanese authorities declared the 20 km evacuation zone a no-go area which may only be entered under government supervision. In April 2012, Units 1-4 were decommissioned. Units 2-4 were decommissioned on April 19, while Unit 1 was the last of these four units to be decommissioned on April 20 at midnight 00:00 Japan Standard Time. In December 2013 TEPCO decided none of the undamaged units will reopen. The sister plant Fukushima II Nuclear Power Plant, or Fukushima Dai-ni (“number two”), is located to the south and also run by TEPCO. It did not suffer a serious accident during the tsunami as cooling continued uninterrupted after the disaster.