A science ministry panel decided Oct. 6 to adopt a radiation exposure level of 1 to 20 millisieverts a year as the benchmark for residents to safely live in Fukushima Prefecture, where a quake-stricken nuclear power plant is situated.
A science ministry panel decided Oct. 6 to adopt a radiation exposure level of 1 to 20 millisieverts a year as the benchmark for residents to safely live in Fukushima Prefecture, where a quake-stricken nuclear power plant is situated.
The decision, by a task force of the ministry's Radiation Council, is in line with a recommendation by the International Commission on Radiological Protection.
The council has been tasked with discussing standards for radiation exposure levels. An official decision on this matter is expected to be made as early as late October.
The ICRP recommendations request that as low a value as possible be set as a target radiation exposure level during the transitional period from an emergency to normal living conditions.
Under the recommendations, 1 millisievert should ultimately be the target figure.
The central government cited the ICRP recommendations when it set radiation standards for defining evacuation zones and using school playgrounds as temporary shelters following the accident at the Fukushima No. 1 nuclear power plant.
The council's main role is to offer advice on radiation-related standards to ministries. The Ministry of Health, Labor and Welfare is expected to shortly ask the council to consider radiation standards for foodstuffs and advise on other matters.
Given that the ministry relies heavily on the advice, the council had discussed since August how to incorporate the ICRP recommendations into domestic laws.
The task force said it would be a very effective approach if municipal governments set specific target radiation values, for instance, 5 millisieverts or 10 millisieverts a year, based on radiation levels recorded by respective municipal areas.