The Japanese government is to review the radiation levels used to decide the size of the evacuation zone around a nuclear plant damaged by the March 11 earthquake and tsunami, media reports said Wednesday.
"The current standards represent safety in the event of absorbing a huge amount of radiation in a short period," Chief Cabinet Secretary Yukio Edano said, according to the Kyodo News agency.
He said that a change might be needed because residents near the damaged Fukushima Daiichi nuclear power plant in north-east Japan risk absorbing radiation over a long period, DPA reported.
The government ordered people out of their homes within a radius of 20 kilometres from the plant and told those between 20 and 30 kilometres away to stay indoors.
The size of the zone was based on radiation levels of more than 50 millisieverts requiring evacuation and staying inside when they are over 10 millisieverts.