More than 80 percent of nuclear reactors in Japan will be idled after Kansai Electric Power Co. in the western region suspends operation of one of reactors at its power plant in Fukui Prefecture for a regular inspection late Friday evening, Kyodo News Agency reported.

That will leave only 10 out of Japan’s 54 reactors in service. While Kansai Electric expects the inspection to be completed in about four months, it remains uncertain when the utility will be able to start the reactor as the time needed for the government’s safety evaluation has yet to be determined.

In addition, the Fukui prefectural government does not intend to approve resumption of operation based only on that safety evaluation in the wake of the disaster at the Fukushima Daiichi power plant triggered by the March 11 earthquake and tsunami.

Kansai Electric will also idle two more reactors in Fukui for regular checks in December and another next February. As a result, all of the utility’s 11 reactors will be out of service after February. The Fukushima accident has forced the nation to rely more on fossil-fuel-fired plants to make up for nuclear capacity.