Make use of safe reactors, even ones over 40 years old, for stable electricity supply

A 10th nuclear reactor has been restarted since the 2011 Great East Japan Earthquake. It is vital to make active use of available nuclear power plants and ensure a stable supply of electricity.

After a 10-year break, Kansai Electric Power Co. has restarted the No. 3 reactor at its Mihama nuclear power plant in Fukui Prefecture. This was the first reactor reactivated since the No. 4 reactor of Kyushu Electric Power Co.’s Genkai nuclear power plant in June 2018 and the first nuclear unit in Japan to operate beyond the government-mandated 40-year service period.

Currently, the operating period of nuclear reactors is limited to 40 years in principle. Some people are concerned about the restart of this reactor at the Mihama plant. However, in recent years, a 60-year operating period has become mainstream in the United States, and no other country has set a 40-year service period as a yardstick for the aging of reactors.

Kansai Electric should make efforts to dispel concerns by publicizing measures to prevent aging-related deterioration, such as through the maintenance and inspections the utility has so far conducted in a planned manner.

The Nuclear Regulation Authority approved the extended operation of the reactor at the Mihama plant in 2016. This can be called a reasonable judgment based on an appropriate evaluation of the facility’s performance. With the consent of the local prefectural governor in April this year, Kansai Electric finally reached the point where the reactor could be reactivated, but there are still a mountain of problems to be solved.

Kansai Electric will not be able to meet the Oct. 25 deadline to complete the setup of required facilities as counterterrorism measures. For that reason, it will be forced to halt the operation of the reactor again just before the deadline.

The utility’s promise to decide by the end of 2023 on a candidate site for an intermediate storage facility for spent nuclear fuel outside Fukui Prefecture will be a burden. A plan to use another intermediate storage facility in Mutsu, Aomori Prefecture, has been met with opposition from local residents, making the prospects difficult.

Storing spent nuclear fuel is not an issue that a utility alone should deal with. It is hoped that the central government will play a leading role in promoting coordination among relevant parties.

As for nuclear reactors that are over 40 years old, local communities have agreed to restart the Nos. 1 and 2 reactors at the Takahama plant in Fukui Prefecture, and facilities to protect the reactors from terrorist attacks are under construction. The No. 2 reactor at Chugoku Electric Power Co.’s Shimane plant, whose operation has been suspended for nearly 10 years, has effectively passed the NRA’s safety screening.

For the time being, the central government should make the most of these existing nuclear reactors. It is also necessary to clearly show the government’s intention to aim for constructing new reactors in the future.

Prime Minister Yoshihide Suga has set a target of reducing greenhouse gas emissions by 46% in fiscal 2030 from the fiscal 2013 level. Although he mentioned the promotion of renewable energy to that end, this type of energy source alone is insufficient. It is vital to make effective use of nuclear power as well.

Recently, there has been a series of closures and suspensions of aging thermal power plants, raising concerns about power shortages in summer and winter. It has become more important than ever to take advantage of the ability of nuclear power plants, which stably produce electricity and emit no carbon dioxide.

— The original Japanese article appeared in The Yomiuri Shimbun on June 25, 2021.