About 70% of residents returning to their homes in three of the municipalities in Fukushima Prefecture evacuated after the 2011 nuclear accident will be exposed to radiation of 1 millisievert or less a year, a level set as a long-term goal for decontamination, according to an official survey undertaken by the Nuclear Regulation Authority (NRA). The survey covered selected residents in the towns of Kawamata and Tomioka and in the village of Katsurao, assuming that they resumed daily lives at their homes. The results were announced at a press conference at the Fukushima prefectural government office in Fukushima city on July 6 by the Japan Atomic Energy Agency (JAEA), which cooperated in the undertaking.
The survey was conducted in the fall of 2015 covering selected evacuees from the three municipalities which had requested it. Surveyed were 29 evacuees from Kawamata, 25 from Tomioka and 11 from Katsurao. They were asked about daily activities before the disaster at Tokyo Electric Power Co.’s Fukushima Daiichi plant. The NRA measured radiation dosages in places frequented by the residents such as farmland and community roads based on the hearings from them, and estimated each resident’s annual dosage on the basis of the hours of stay there and other factors.
The survey estimated the average annual dosage at or less than the 1-millisievert level for 21 people in Kawamata or 70% of the residents covered, 15 or 60% for those in Tomioka and nine or 80% in Katsurao. The maximum dosage was 2.62 millisieverts in Kawamata, 1.78 millisieverts in Tomioka and 1.84 millisieverts in Katsurao. Additional exposure to radiation in evacuated areas has become relatively small in the wake of progress in cleanup work and other factors, according to the JAEA.