Cumulative radiation outside the 20-km radius of the crippled Fukushima No. 1 nuclear power plant in the past three months has reached as high as 82 millisieverts, more than four times the limit of 20 millisieverts a year, a science ministry estimate showed Tuesday.
The highest level was detected in a part of Namie, Fukushima Prefecture, around 22 km northwest of the nuclear plant crippled since the March 11 earthquake and tsunami, according to the data compiled by the Education, Culture, Sports, Science and Technology Ministry.
Namie is among the designated evacuation areas lying outside of the no-entry zone where radiation levels are feared to exceed the annual limit of 20 millisieverts. Of 160 monitoring sites in the designated areas outside the no-entry zone, 23 registered radiation levels exceeding 20 millisieverts over the three-month period, the ministry said.
Outside the areas subject to evacuation, an area in the city of Minamisoma had an estimated cumulative level of 20.4 millisieverts a year since the start of the crisis.