OSAKA —Kansai Electric Power Co has applied to the nuclear regulatory body for permission to operate a reactor in western Japan beyond the government-mandated 40-year service period.

The power company asked the Nuclear Regulation Authority for approval to continue to run a unit built in 1976 at its Mihama plant in Fukui Prefecture.

“Nuclear power is very important to ensure stable power supply. We would like to continue to use it,” Kansai Electric President Makoto Yagi said at a press conference Thursday after the company lodged the application.

A regulation brought in after the 2011 Fukushima nuclear plant disaster prohibits in principle the operation of nuclear reactors for more than 40 years. But they may be allowed to continue operating for up to 20 more years if they can obtain safety clearances from the nuclear regulation watchdog.

The Japanese government is seeking to restart nuclear power plants, which were all shuttered after the March 2011 Fukushima disaster, as it looks to generate a fifth of the nation’s overall electricity by nuclear power plants in 2030 to cut greenhouse gas emissions and lower fuel costs.

Only two reactors have resumed operating in Japan under tougher safety rules introduced after the 2011 disaster.

By closing at least some aging reactors and carrying out safety screening of every reactor before it is allowed to go back online, the government aims to reassure a Japanese public still wary of nuclear power’s safety.

The Osaka-based utility hopes the restart of the reactor will help it end years of losses, as it estimates the resumption will improve its earnings by 6 billion yen ($49 million) a month.

Kansai Electric became the first company to attempt to keep reactors running beyond the 40-year limit in April when it made a similar application for two aging reactors at its Takahama plant.

The Mihama reactor needs to pass the regulator’s screenings, regarding both the general safety of the plant and measures against aging equipment to be brought back online.

© KYODO