Radiation has risen to high levels above the spent-fuel pool at reactor No. 4 and its temperature is rising, the nuclear safety agency said Wednesday, indicating the fuel rods have been further damaged and are emitting radioactive substances.
The radiation level 6 meters above the spent-fuel storage pool at the crippled Fukushima No. 1 nuclear plant was measured at 84 millisieverts per hour Tuesday. Normally, it's 0.1 microsievert.
The temperature of the pool was 90 degrees, compared with 84 before it caught fire on March 15 in a suspected hydrogen explosion, the agency said.