Japan’s Nuclear Resurgence: Safer Alternatives

Earthquake predictions mean reactor reactivations need a rethink

Jan 27, 2025

Changes are taking place in Japan’s energy sector that a few years ago were thought impossible. However, even more adjustments in energy policy are needed to secure both needed energy for the country and to ensure the safety of its citizens. Whether or not the government has the resolve to make these changes remains uncertain.

Last year, with Japan still edgy about nuclear power in the wake of the disastrous 2011 earthquake that destroyed the Fukushima-Daiichi nuclear plant, which led the government to suspend operations at all of its remaining 48 nuclear power reactors, two were restarted with three more approved but not yet operational. Even more striking, one of the restarted reactors included Chugoku Electric Power’s Shimane Unit 2 in Onagawa, the nuclear power plant located closest to the epicenter of the March 2011 earthquake and tsunami. Restarts however remain slow due to a more stringent safety inspection and authorization process established in the wake of the disaster.

By the end of 2024, Japan had restarted 14 nuclear reactors that had been idled since the Fukushima disaster, which led to the evacuation of more than 150,000 residents and widespread radioactive contamination. After the meltdown, Japan’s nuclear plants faced global scrutiny that caused other countries, including neighboring Taiwan, to pivot away from nuclear power. Anti-nuclear sentiment in Europe is still strong, with some countries completely phasing out nuclear power.

Before the disaster, nuclear power made up around one-third of Japan’s energy mix. By 2015, that number had dropped to zero. Today, nuclear power makes up just 7 percent. But the government wants more.

The Japanese populace is also becoming more pro-nuclear. In February 2023, for the first time since 2011 a slight majority, 51 percent, of Japanese citizens in an annual survey by the daily newspaper Asahi Shimbun showed support for restarting the country’s nuclear reactors. That’s up from an average 30 percent approval rating over previous surveys stretching from 2011 to 2023. Public approval for nuclear power seems to have been motivated by energy supply shortage fears coming soon after Russia invaded Ukraine.

Also in 2023, the Japanese cabinet seized the initiative by approving a policy that would maximize the use of existing reactors by restarting as many as possible. The plan includes prolonging the operational life of aging nuclear plants beyond the current 60-year limit along with permission to construct "next-generation innovative reactors" to replace about 20 reactors that are set to be decommissioned.

More changes were also underway late last year. In December, the Japanese Ministry of Economy, Trade and Industry released a draft revision of the country's basic energy plan, striking the statement that the country would reduce its dependence on nuclear power. That change isn’t just semantics, it indicates a significant energy policy shift, calling for renewables to make up 40 percent-50 percent of Japan’s power generation mix by 2040 and nuclear to make up around 20 percent.

Yet, just as Japan was getting used to a renewed nuclear power future, another earthquake struck, raising fresh doubts over nuclear safety. On January 1, a 7.5 magnitude earthquake struck Japan’s Noto Peninsula, leaving dozens dead and hundreds injured. A subsequent tsunami warning was issued in cities located nearby the Noto Peninsula on the Japan Sea side of the country, including the Niigata, Toyama, and Ishikawa prefectures, according to the US Embassy in Japan. Even more troubling, on January 13 at 9:19 p.m., two Japanese nuclear reactors were rattled when a magnitude 6.6 earthquake struck southwest Japan, prompting a tsunami advisory for parts of the region. All advisories were lifted by 12 am.

Two days later, a Japanese government committee on earthquake research changed its estimate of the chance of a Nankai Trough megaquake in the next 30 years to around 80 percent, from the previous 70 percent to 80 percent. Nankai Trough is an ocean-floor trench that runs along Japan's Pacific coast where the Eurasian and Philippine Sea tectonic plates meet. The fault that underlies the submarine trough, the Nankai megathrust, is the source of the often devastating megathrust earthquakes experienced in that part of Japan.

However, it’s this very real threat of more earthquakes that should give Japanese government officials pause over its renewed nuclear power policy. One way to offset the threat of another nuclear disaster would be for Japan to develop more renewable energy, far more than the 40 percent to 50 percent allocation called for by 2040.

Since Japan has limited available land for solar power plants, energy analysts say it should build more rooftop solar panels for both residential areas and industry. These panels could generate enough electricity to reduce manufacturing plants’ dependence on both fossil fuels and nuclear needed for power generation. Japan should also develop a robust near shore and offshore wind power sector. Notably, Japan has vast wind power potential that remains undeveloped, a Zero Carbon Analytics report found. Japan’s total technical potential for offshore wind generation is over 9,000 TWh/year, more than nine times its projected electricity demand in 2050, the report added.

Even more promising, Japan is also particularly well-suited to floating offshore wind power development since it has the seventh largest coastline in the world, stretching some 30,000 kilometers, with water depths that drop quickly (on average up to 200 meters) relatively close to the shore. Renewables, led by offshore wind, would help Japan quickly decrease fossil fuel and nuclear reliance and instead generate 70 percent of its electricity in just over 10 years, a recent Japan Energy Watch report said. These findings are without dispute, analysts say. They should propel the government to act quickly and rethink its nuclear power development and opt instead for safer alternatives.