4 Mars 2013
March 4, 2013
The government's Nuclear Regulation Authority (NRA) has drawn up new guidelines for nuclear disaster countermeasures, providing specific standards for evacuations in the event of another nuclear plant accident. In October last year, the panel decided to expand the priority zone for nuclear disaster prevention measures from a 10-kilometer radius around nuclear power stations to 30 kilometers. Authorities must implement detailed measures that dispense of the safety myth surrounding nuclear power plants.
Disaster prevention measures are the last line of defense in the five-tier layer protecting people from the radioactive substances from nuclear power stations. While guidelines must be strengthened, local governments also have a crucial role to play in protecting local residents from radiation in the event of a serious accident. Twenty-one prefectural governments and 135 municipal governments around Japan's nuclear plants are drawing up nuclear disaster prevention plans, but their work has been delayed because it took the NRA longer than initially expected to work out its guidelines.
The guidelines are complex and there are numerous challenges to overcome. Local bodies are supposed to work out their nuclear disaster prevention plans by the end of this month, but some have never compiled such plans before. The NRA should help them, even if the process is prolonged.
Unlike the previous guidelines, the new guidelines call for a response before radioactive substances start leaking from damaged nuclear reactors. Residents within five kilometers from a nuclear plant are required to evacuate if a reactor faces serious trouble. Iodine tablets will be delivered in advance to residents in such areas so they can quickly guard their thyroid glands from radiation exposure in the event of a nuclear disaster. We can regard these measures as appropriate.
In areas located more than five kilometers from a nuclear plant, residents will be ordered to evacuate when airborne radiation levels reach 500 microsieverts per hour, and those who have difficulties fleeing their neighborhoods will be instructed to stay indoors. Under the guidelines, local bodies are required to stockpile iodine tablets and deliver them to residents in such areas if necessary.
However, critics have raised questions about whether 500 microsieverts is an appropriate level for ordering evacuations. The NRA should explain the basis for its figure. It should also consider delivering iodine tablets to households outside the five-kilometer zone in advance.
There are many other problems that need to be solved. The system to monitor radiation levels in the event of a serious nuclear accident must be firmly established to enable local bodies around nuclear power stations to evacuate their residents depending on levels of airborne radiation. Questions remain about how to establish such a system. Even those outside the 30-kilometer radius could be exposed to radiation if radioactive substances drift into their communities -- as was the case with the Fukushima Prefecture village of Iitate. Officials must work out countermeasures against such radiation exposure. They must also clearly establish the procedure for instructing local residents to take iodine tablets in case of a serious nuclear accident.
Authorities' response to the Fukushima nuclear disaster was sorely lacking. Information was not sufficiently provided to residents in areas affected by the crisis, adversely affecting the process of instructing them to stay indoors or evacuate.
If another nuclear plant accident occurs in the future, the central and local governments must not expose residents to radiation or endanger their lives as a result of deficiencies in their disaster countermeasures. Lessons learned from the Fukushima nuclear crisis must be put to good use in constantly reviewing the guidelines and working out regional nuclear disaster prevention measures.