22 Janvier 2013
January 22, 2013
Japan's nuclear industry watchdog plans to apply stricter evacuation standards than the international norm for cases in which residents at risk from a nuclear accident need to be moved from areas outside the immediate 5-kilometer radius danger zone.
A study team under the Nuclear Regulation Authority on Jan. 21 drafted standards that local governments will be obliged to follow in issuing instructions to residents in such times of crisis.
Under the draft standards, residents living outside a 5-kilometer radius would be told to evacuate immediately or stay indoors if radiation levels reach 500 microsieverts per hour.
The NRA team set the threshold lower than the International Atomic Energy Agency’s 1,000 microsieverts, citing lessons from the disaster at the Fukushima No. 1 nuclear power plant.
If residents stay indoors, they would subsequently evacuate after the radioactive plume disappears.
The standards are expected to be incorporated into guidelines on nuclear disaster countermeasures, which will be revised in February.
In previous revisions last October, it was decided that residents within a 5-kilometer radius will evacuate immediately when a nuclear accident is reported.
Residents outside a 5-kilometer radius would be told to temporarily relocate within a week if radiation levels reach 20 microsieverts per hour, which are also lower than the IAEA’s 100 microsieverts.
Locally produced food and drinks would be measured for radioactive concentrations if radiation levels reach 0.5 microsievert per hour, compared with the IAEA’s 1 microsievert.
Residents would be told not to drink water or milk if they contain 300 becquerels of radioactive iodine per kilogram or more, or 200 becquerels of radioactive cesium or more.