KEPCO Eyes Building, Replacing Nuclear Reactors in Japan; 1st Time Geological Surveys to Be Resumed Since Fukushima Accident

The Yomiuri Shimbun

17:48 JST, July 19, 2025

Kansai Electric Power Co. has formulated its policy of resuming geological surveys to build a nuclear reactor and replace existing ones at the Mihama nuclear power plant in Fukui Prefecture, it has been learned.

The surveys had been suspended following the 2011 Great East Japan Earthquake. If realized, it would be the first step toward building and replacing new nuclear reactors, which the government considers to be a part of decarbonization efforts.

KEPCO started its geological surveys to construct a new reactor at the Mihama nuclear plant in 2010 but suspended them after the nuclear accident at Tokyo Electric Power Company Holdings, Inc.’s Fukushima No. 1 nuclear power plant.

After resuming the surveys, KEPCO plans to compile a basic design and submit applications for approval to the Nuclear Regulation Authority. If approved, KEPCO will proceed with construction. The company envisions building next-generation reactors, including advanced light-water reactors, which are considered to be very safe.

According to sources, KEPCO plans to explain its policy to local governments and other concerned parties in the near future.

The No. 3 reactor at the Mihama nuclear plant is currently in operation, while Nos. 1 and 2 will be decommissioned.

To ensure a stable supply of electricity, KEPCO believes it is necessary to accelerate such moves as replacing existing reactors.

KEPCO President Nozomu Mori has made it clear the company will “proceed with looking into the construction of a new nuclear reactor.”

The operation of all nuclear power plants was suspended in Japan following the accident at the Fukushima No. 1 nuclear power plant. However, the process of restarting operations has been underway at KEPCO and other power companies, including Kyushu Electric Power Co. and Chugoku Electric Power Co.

In October 2024, Tohoku Electric Power Co.’s Onagawa No. 2 reactor in Miyagi Prefecture was the first nuclear reactor to resume operations in eastern Japan since 2011. Kyushu Electric has also started to consider building a new reactor.

The 7th Strategic Energy Plan, approved by the Cabinet in February this year, states it is necessary to maximize the use of decarbonized power sources, including nuclear power.

The plan also eased the requirements for replacing existing reactors and states a target of having nuclear power generate 20% of the total electricity in fiscal 2040.

Due to artificial intelligence becoming more widely used, data centers that consume large amounts of electricity are being constructed in various parts of the country, and demand for electricity is expected to increase.

As nuclear reactors deteriorate with age, the government is said to have decided it is necessary to develop stable power sources as soon as possible.

However, building a new nuclear reactor requires an investment of \500 billion to \1 trillion.

As it creates a large financial burden on privately run electric companies, discussions on securing funds and building a support framework may accelerate in the future.

“We believe it is time to start seriously considering building a new reactor and replacing existing ones, taking into account the government’s policies,” said a KEPCO representative. “But we haven’t made any decisions about specific plans at this point.”