AmiMoJo writes "Japan's nuclear regulators have raised the level of severity of the radioactive water leak from a tank at the Fukushima Daiichi nuclear plant. It is now a level-3 serious incident. The revision from level 1 is based on estimates of the volume of radioactive substances leaked. The International Atomic Energy Agency supports the revision. They say the tank leak can be assessed separately from the Fukushima Daiichi crisis as a level 3 incident. Japanese experienced a level-3 nuclear event in 1997 with the fire and explosions at a fuel reprocessing plant in Tokai Village, Ibaraki Prefecture. 37 workers there were exposed to the leaked radioactive substances."