Japan's sole operating nuclear reactor, the No. 3 unit at Hokkaido Electric Power Co.'s Tomari plant, will be shut down at around 11 p.m. May 5 for a regular inspection, the utility said Wednesday.
The suspension of operations at Tomari will probably result in all 50 of the nation's commercial reactors remaining idle, as the government is considered to have little chance of winning approval from local governments and residents to restart two reactors in Fukui Prefecture by that time.
Hokkaido Electric initially planned to shut down reactor 3 at the Tomari plant in the second half of April, but decided to push back the inspection by about a week to maintain a stable supply of electricity to its service area, officials said.
Just before last year's devastating earthquake and tsunami sparked the triple-meltdown crisis at the Fukushima No. 1 power station, Japan relied on atomic power for about 30 percent of its electricity supply.
But the government introduced a tightened safety regimen in light of the nuclear crisis, including mandatory stress tests for all reactors nationwide that in part assess reactors' robustness to temblors and tsunami whose power exceeds the maximum initial assumptions made during their design.
None of the reactors idled for routine checks have been given the go-ahead to resume operations since the Fukushima disaster started in March 2011.
The central government is eyeing two reactors at Kansai Electric Power Co.'s Oi plant in Fukui Prefecture as the first to go back online, but opposition from local residents and governments, who remain fearful about the safety of nuclear power, has so far prevented the units from going back onstream.