Tokyo Electric Power Co. said Wednesday that one of its female employees at the crisis-hit Fukushima No. 1 nuclear plant was exposed to radiation exceeding three times the legal limit of 5 millisieverts in a three-month period.
The woman, who is in her 50s, has no health problems now, but the government’s nuclear safety agency said two more female workers may also have been exposed to radiation in excess of the limit. The agency called on the utility to investigate the reason and take measures to prevent a recurrence.
Hidehiko Nishiyama, a spokesman for the Nuclear and Industrial Safety Agency, told a news conference the situation was “extremely deplorable,” but added that all female employees had left the radiation-leaking plant on March 23.
According to Tepco and the agency, 19 female employees were working at the six-reactor complex following the March 11 earthquake and tsunami, and one was exposed to a total of 17.55 millisieverts of radiation.
The woman was found to have suffered more internal than external radiation exposure, with the internal exposure reaching 13.6 millisieverts.
Another agency official said Tepco needs to explain why the worker suffered so much internal exposure.
Tepco and the agency said the woman had been refueling fire trucks and working inside a building on site. She had been wearing a mask, but may have inhaled radioactive material when putting it on or taking it off.
A Tepco official acknowledged during a press conference that its radiation-dose management should have been more stringent.
Under Japanese law, radiation workers are not permitted to be exposed to more than 100 millisieverts over five years, or more than 50 millisieverts in one year.
For female workers, the limit is 5 millisieverts in a three-month period, considering they may become pregnant. For the general public, the limit is 1 millisievert per year, excluding exposure from medical procedures.
Big underground tank
Prime Minister Naoto Kan is considering setting up a big underground tank in the compound of Tokyo Electric Power Co.’s radiation-spewing Fukushima No. 1 nuclear plant to prevent contaminated water from spilling into the sea, a fishery official said Wednesday.
“There is bedrock 46 meters underground. The government has found that no tainted water will seep below (the bedrock) and is considering building a tank there,” Ikuhiro Hattori, who heads the National Federation of Fisheries Cooperatives Associations, quoted Kan as saying.
Hattori talked to the press after he and other executives of the federation held talks with Kan, during which they lodged a protest over the government’s allowing Tepco to release a large amount of radioactive water into the Pacific in early April.