Nuclear plant workers in Japan will be allowed to be exposed to more than twice the current level of radiation in emergency situations, according to the Nuclear Regulation Authority’s Radiation Council.
The radiation exposure limit will be raised from the current 100 millisieverts to 250 millisieverts in emergencies, the radiation council announced in a report released July 30.
The higher level is still only half of the accepted international safety level of 500 millisieverts set by the International Commission on Radiological Protection, an influential independent organization that provides guidelines on radiation protection, for rescue workers in emergency situations at nuclear facilities.
The new cap will be activated from April 2016 after revisions to the nuclear reactor regulatory law and the Industrial Safety and Health Law.
The limit was temporarily raised to 250 millisieverts by the radiation council following the triple meltdown at the Fukushima No. 1 nuclear power plant triggered by the Great East Japan Earthquake and tsunami in March 2011.
The decision was quickly made by the council members through e-mail discussions as the 100 millisieverts limit could have caused a shortage of workers tackling the emergency at the plant. Later, the limit was returned to 100 millisieverts.
Under the revised law, the exposure limit for plant workers will be immediately raised to 250 millisieverts when certain conditions arise, including the risk of radioactive materials leaking from the facility into the surrounding area.
The workers affected will include employees of utility companies and their contractors, inspection officers from the Secretariat of the NRA and other on-field workers.
Of the 174 workers who were exposed to radiation doses more than 100 millisieverts following the Fukushima accident, six were exposed to 250 millisieverts or more.
The radiation council decided that workers are protected if they wear masks and other gear even when exposed to 250 millisieverts. The health damage from acute radiation poisoning below that limit is negligible, it said.
The council’s report calls for nuclear plant operators to carefully explain to workers tackling emergency situations about their tasks and obtain their consent to work in such an environment.
It also requests utility companies to conduct proper training of workers, while one of the council members also called on them to conduct follow-up medical checks to detect cancer and other illnesses.
The report also acknowledges that nuclear plant workers could be required to engage in tasks that cause them to be exposed to more than 250 millisieverts in acute emergency situations.
At Kyushu Electric Power Co.’s Sendai nuclear power plant in Kagoshima Prefecture, which the company aims to restart in August, workers will carry out their tasks with an exposure limit of 100 millisieverts until the maximum limit is raised to 250 millisieverts.
A plant worker who has worked at nuclear facilities for 20 years said he suspects that workers from subcontractors will agree to work under the raised limit.
“The cancer checkups and other measures also sound to me as stopgap efforts to ease our anxiety,” he said.