A panel of the Nuclear Regulation Authority reached broad agreement Thursday to set standards tougher than international guidelines for triggering an evacuation order in the event of a nuclear disaster.
The standards drafted by the panel would set the radiation level at 500 microsieverts per hour for ordering residents within 5 to 30 km of a nuclear power plant to evacuate within several hours after a meltdown disaster starts.
That would be far lower than the 1,000 microsieverts recommended by the International Atomic Energy Agency.
Residents within 5 km of a nuclear plant can be ordered to evacuate right after the release of radioactive substances is detected.
The new standards, which are to be finalized before the end of this month, would set a radiation level of 0.5 microsievert per hour for advising residents to refrain from eating local food products until they are confirmed safe.
The standards are designed to prevent aggregate radiation exposure from exceeding 50 millisieverts during the first week of a crisis. The IAEA standard is 100 millisieverts.
Until now, evacuation orders are to be issued if the System for Prediction of Environment Emergency Dose Information (SPEEDI) predicts radiation exposure will reach 50 millisieverts.