Nuclear Reactor Restart at Kashiwazaki-Kariwa Plant Expected to Power Economic Growth

The Yomiuri Shimbun

21:00 JST, November 22, 2025

Movement has begun toward restarting the No. 6 reactor at Tokyo Electric Power Company Holdings Inc.’s Kashiwazaki-Kariwa nuclear power plant within the current fiscal year.

With the restart of a TEPCO nuclear reactor, which had long appeared hopeless after the 2011 meltdowns at the company’s Fukushima No. 1 nuclear plant, coming into sight, a senior official of the Economy, Trade and Industry Ministry spoke with deep emotion.

“Japan’s economic growth and energy security cannot be achieved without nuclear power. We have reached a major turning point that will determine our national strength,” the official said.

Before the 2011 Great East Japan Earthquake, 54 nuclear reactors were operating in the country, providing about 30% of the nation’s electricity as baseload power.

However, the quake-triggered disaster changed everything. All reactors were suspended. Even now, 14 years later, only 14 reactors have resumed operating.

A stable supply of electricity is an aspect of infrastructure essential for economic activity and citizens’ daily lives. With a growing sense of crisis, the government shifted its post-quake nuclear policy.

The seventh basic energy plan, approved by the Cabinet in February this year, removed previous wording that had stated the goal was to “reduce dependence on nuclear power as much as possible.” Instead, it sets a new course to “make maximum use” of both renewable energy and nuclear power.

The industry ministry official said, “This is aimed at having the government take the lead in promoting the restart.”

Behind the growing sense of crisis is the prospect that electricity demand will surge in the future. The proliferation of artificial intelligence will lead to more data centers, consuming huge amounts of electricity. Without sufficient power, Japan will lose the global race for AI development.

Meanwhile, the government has set a goal of achieving carbon neutrality by 2050. Renewable energy sources such as solar power are unstable, dependent on weather conditions, and have limited room for further development. Electricity rates charged by TEPCO, with its nuclear plants stopped, have risen about 30% from pre-quake levels.

Currently, there is no source but nuclear power that meets the requirements of “decarbonization,” “stability” and “low price.” The basic plan sets a policy to raise nuclear power’s share of Japan’s power supply from roughly 10% now to about 20% by fiscal 2040. This will require restarting at least 30 reactors.

The government has strongly backed the restart of the Kashiwazaki-Kariwa nuclear power plant, viewing it as the key to accelerating the restarts.

After the basic plan was formulated, the government kept Yoshifumi Murase, commissioner of the Agency for Natural Resources and Energy, in his post for an unusual third year, assigning him “the final and most important task,” according to the ministry.

At a meeting of relevant ministers in August, former Prime Minister Shigeru Ishiba called for preparing for the restarting of the Kashiwazaki-Kariwa plant such as reviewing countermeasures in case of disasters. The government then promised Niigata Prefecture unprecedented support worth around ¥100 billion. A government official reflected, “We did everything we could to meet local demands.”

Looking beyond the restart of existing reactors, the government intends to realize the construction of new reactors. The coalition agreement between the ruling Liberal Democratic Party and the Japan Innovation Party sets goals that include “accelerating the development of next-generation innovative reactors and fusion reactors.”

Kansai Electric Power Co. (KEPCO) has begun surveys for building a new reactor to replace an old one at its Mihama nuclear power plant in Fukui Prefecture. A senior official of KEPCO welcomes the latest development as “a tailwind for stimulating understanding” for that project.

Takeo Kikkawa, president of the International University of Japan and an expert on nuclear policy, pointed out, “Nuclear power is a decarbonized power source that contributes to energy security and a stable supply of power. For Japan’s nuclear policy, which has long been in decline, the restart of the Kashiwazaki-Kariwa plant is significant.”