Japan’s new nuclear regulatory body on Wednesday decided on new guidelines for nuclear disaster mitigation measures following the Fukushima nuclear crisis last year, expanding the radius of areas that need to make special preparations to up to 30 kilometers from an atomic power plant.
While details need to be fleshed out, such as setting specific criteria for evacuation, the guidelines were revised to meet international standards and rewritten in plain language so as to be more user-friendly, officials of the Nuclear Regulation Authority have said earlier.
Based on the guidelines and other information provided by the authority, local governments hosting nuclear plants and those on the periphery are expected to craft their own disaster mitigation plans and set the scope of the emergency zones by March next year.
The existence of disaster mitigation plans is not a legal requirement when resuming the operation of nuclear reactors, but NRA Chairman Shunichi Tanaka has said that it will be difficult in reality to see reactors go back online unless local governments concerned devise such plans in line with the new guidelines.
The most notable change in Japan’s new emergency preparedness is that emergency zones have been widened to a 30-km radius around each nuclear power plant from 10 km.
A “precautionary action zone” extends about 5 km from a plant and residents are asked to evacuate immediately after an accident occurs, while an “urgent protective action planning zone” covers a radius of about 30 km and residents are asked to be prepared for evacuation depending on the situation, such as a rise in radiation levels.
But recently-announced projections for the spread of radiation showed that points more than 30 km away from some nuclear plants may see radiation released a week after a severe accident reach 100 millisieverts, a level where evacuation is recommended.
Tanaka has said that 30 km is enough for emergency zones, but local governments may have difficulty in deciding the exact size of the zones.
The NRA also has to set criteria for starting evacuation and taking other protective actions to enable swift decision-making even in the event of unexpected developments, but the guidelines did not make any specific proposals and said that the matter should be considered.
Other issues that need to be studied included the distribution of iodine tablets in advance to prevent residents developing thyroid cancer.
In the case of the Fukushima crisis, which saw three reactors suffer meltdowns, residents living within a 20-km radius of the plant and some areas beyond had to evacuate.
Reports by accident investigation panels have criticized the fact that residents did not receive accurate information on how serious the incident was when they were ordered to evacuate and that the evacuation process caused great confusion. In addition, not many people took iodine pills because of a delay in actions by the central government.
Filed under: 8.Eathquake & Nuclear accident