The Kagoshima Prefectural Government estimates it will take about 29 hours for most people living within 30 km of the Sendai nuclear power plant to flee by vehicle in case of a serious nuclear accident.
The estimate Thursday comes at a time when Kyushu Electric Power Co.'s Sendai complex is considered the closest to restarting.
The prefectural government said the projection is in line with a target in new nuclear-disaster mitigation guidelines set after the Fukushima disaster, which state that residents are to flee outside the 30-km zone within 24 hours after an evacuation order is issued.
The estimate was based on an assumption that authorities will try first to evacuate about 5,000 residents within 5 km of the plant, but that about 40 percent living in the 5- to 30-km ring will start to flee on their own initiative.
Of a total 13 scenarios considered, the prefectural government found that the evacuation of 90 percent of about 210,000 residents within the 30-km area would take the longest time when they cannot use the Minami-Kyushu expressway. The time needed was 28 hours and 45 minutes.