The government said Friday it will reclassify three partially evacuated municipalities near the Fukushima No. 1 nuclear plant in April to facilitate the return of their residents, officials said.
The municipalities will be newly designated using three categories, depending on local levels of radiation.
In areas where levels of 20 millisieverts or less per year are recorded, preparations will be made for evacuation orders to be lifted. The government's current threshold for issuing mandatory evacuation directives is 20 millisieverts a year.
In zones with radiation readings of between 20 and 50 millisieverts, residents will be allowed to travel back and forth but won't be permitted to return permanently.
But in areas where levels are currently at 50 millisieverts or more and are expected to remain at 20 millisieverts or above for the next five years, it will be difficult for evacuees to return.
Evacuation orders will be lifted in parts of the municipalities with 20 millisieverts or less once infrastructure is restored, and after schools and other public facilities have been decontaminated to a degree deemed satisfactory.
A total of 11 local governments were issued evacuation directives and advisories after the nuclear crisis started last March, but the other eight municipalities have yet to reach agreement with the central government over the reclassification process.
The government issued its first evacuation directive, covering residents within a 20-km radius of the No. 1 power plant, soon after the quake-tsunami disasters wrecked its reactors.
Later, it also designated areas with high radiation levels outside the no-go zone as emergency evacuation preparation zones, where residents were required to be on standby in case the nuclear disaster worsened.