– Fukushima workers’ exposure tops 650mSV (NHK, June 10, 2011):
Detailed tests have found that 2 workers who were exposed to radiation at the crippled Fukushima nuclear plant received doses of more than twice the government-mandated emergency limit.
The men in their 30s and 40s were each found in early June to have been exposed to over 250 millisieverts — the new higher limit for exposure that the government introduced after problems began at the Fukushima Daiichi plant.
The National Institute of Radiological Sciences conducted 2 more rounds of detailed tests to measure the amount of radioactive iodine and cesium the 2 men could have inhaled.
After analyzing the men’s work shifts since the March 11th disaster, the Institute concluded that the man in his 30s was exposed to 678 millisieverts, and the man in his 40s, 643 millisieverts. Internal exposure accounted for more than 80 percent of the figures.
The 2 men were on duty in the central control rooms of reactors No.3 and No.4. They have told the health and labor ministry that they don’t remember whether they wore protective masks or not when a hydrogen explosion occurred at the No.1 reactor on March 12th.
The Institute said separately that it is conducting detailed tests on another Fukushima worker in his 50s, who could have received a radiation dose above the emergency limit.