Japan's Fukushima Daiichi Nuclear Power Plant, damaged by the March 11, 2011 earthquake and tsunami, joins a listing of 9 major nuclear accidents rated on the IAEA's International Nuclear and Radiological Event Scale (INES) as the worst the world has seen.
The INES scale, introduced in 1990 by the International Atomic Energy Agency, is logarithmic, with each increasing level representing an accident approximately ten times more severe than the previous level – similar to the Richter scale used to judge the magnitude of earthquakes.The Presurfer