On March 11, 2011 the Tohoku earthquake and tsunami hit Japan. This was said to have been one of the main reasons behind Fukushima Daiichi which was the largest disaster since the Chernobyl disaster of 1986, coming in as a level 7 on the International Nuclear Event scale.

The plant consisted of 6 boiling water reactors designed by General Electric but was maintained by Tokyo Electric Power Company. When the earth quake hit 2 of the 6 boilers were shut down for maintenance and the remaining kicked over to emergency generators. Due to the tsunami that came shortly after causing flooding and the generators failed. They were not able to proceed to circulate the coolant water. The pumps stopped and reactors overheated, causing reactors 1,2, and 3 to meltdown. Several hydrogen-air chemical explosions occurred allowing many radioactive gasses to be released. Workers were evacuated for radiation safety.

On March 20th the Japanese government announced that the plant would be decommissioned once the crisis was over. Not only was the radioactive material released into the air but also the ground and ocean. During tho time people were advised to stay away from tap water. A few of the workers were severely injured and some were killed. This not only affected the workers but the people living near the plant, the cancer rate went from 0 to 100.

June 7th the government convened an investigation on the disaster. They interviewed 772 people (plant workers, government officials and evacuees). They said that the government and TEPCO failed to prevent the disaster not because of the tsunami but because they did not invest the appropriate time and mine into planning for a nuclear disaster like this.

http://www.world-nuclear.org/info/Safety-and-Security/Safety-of-Plants/Fukushima-Accident-2011/#.UTlFhZgapzo

http://www.rsc.org/chemistryworld/2013/01/reassessing-health-effects-fukushima-daiichi-nuclear-accident

http://www.tepco.co.jp/en/nu/fukushima-np/handouts/2013/images/handouts_130225_01-e.pdf