TOKYO, April 18, Kyodo:
The radiation level inside the Nos. 1 and 3 reactor buildings at the crippled Fukushima Daiichi nuclear power plant was up to about 57 millisieverts per hour as of Sunday, the government's nuclear safety agency said Monday, acknowledging that it is a level that puts time constraints on any restoration work that must be done there.The Nuclear and Industrial Safety Agency also said that it has found the No. 4 reactor building flooded with water 5 meters high, besides some 60,000 tons of contaminated water already found to be filling up the Nos. 1 to 3 reactor turbine buildings and nearby areas.
Many of the pools of water containing radioactive substances are believed to be a side effect of an emergency measure of pouring massive amounts of water into the reactors and their spent nuclear fuel pools from outside to keep them cool, given that they have lost their key cooling functions following the March 11 earthquake and tsunami.