To facilitate the return of evacuees, the Nuclear Regulation Authority has approved a change in the way radiation doses are monitored around the crippled Fukushima No. 1 nuclear power station that will effectively result in lower readings, but observers warn this could raise public mistrust.
The change calls for basing monitoring on data from dosimeters held by individual residents.
It was proposed by the regulatory commission’s secretariat at its meeting Monday and gained broad-based consensus.
Dosimeter readings tend to be less than half of those using the existing method based on air dose rates, which assume that residents stay outdoors for a total of eight hours a day, according to the NRA Secretariat.
The proposal comes as the government is aiming to lift the evacuation advisory for areas where annual radiation doses are estimated at 20 millisieverts or lower.
The new method is expected to help promote the return of evacuees as well as reduce costs for decontaminating areas tainted by radioactive fallout from the Tokyo Electric Power Co. plant.
But a change in the monitoring method could heighten local residents’ mistrust of the government, observers said.
The NRA Secretariat’s proposal said that a key condition for allowing evacuees to return home is that annual radiation doses estimated from air dose readings not exceed 20 millisieverts.
The government will manage the doses of residents who return home by using dosimeters distributed to them. Over the long term, the goal will be to limit residents’ annual extra radiation exposure stemming from the disaster at the plant to 1 millisievert, the proposal said.
The government will also deploy counseling staff, including municipal officials, doctors and other medical experts, for returnees who are uneasy about radiation, according to the proposal.
Decontamination costs are estimated at ¥2.53 trillion to ¥5.13 trillion in Fukushima Prefecture, excluding radioactive waste disposal
In the city of Fukushima, Ichiro Kowata, 77, an evacuee from Iitate, called for the government to more fully explain the proposed method change. “Younger people say they can’t trust statements that suddenly declare areas to be safe when they have been called dangerous until now,” he said.