The Nuclear Regulation Authority said Wednesday it is considering raising the maximum radiation exposure limit for nuclear workers in emergencies, from the current 100 millisieverts.
“We cannot completely deny the possibility” that accidents involving radiation exceeding the current limit would occur in the future, NRA Chairman Shunichi Tanaka said at an agency meeting, noting that “reality-based” working conditions should be prepared in light of the disaster at Tokyo Electric Power Co.’s Fukushima No. 1 complex after the March 2011 earthquake and tsunami.
The agency will discuss the issue with an eye on international standards, including the 500-millisievert limit considered acceptable by the International Atomic Energy Agency.
After the Fukushima triple meltdown, the maximum limit of cumulative exposure was raised to 250 millisieverts as an emergency measure for workers at the plant. But the limit was lowered back to 100 millisieverts in December 2011, returning it to the same level that existed prior to the nuclear crisis.