Reviving Nuclear Power in Japan

Japan Depends on Nuclear Power

By Takuya Nishimura, Senior Fellow, Asia Policy Point
Former editorial writer for the Hokkaido Shimbun
You can find his blog, J Update here.
April 27, 2026

The military attack on Iran by the United States and Israel and the ensuing blockade of the Strait of Hormuz have had a major impact on Japan’s economy. A shortage of naphtha, which must be shipped through the Strait, has limited Japan’s manufacture of medical equipment, and it is unclear how long the governmental subsidy on gasoline will last. While Sanae Takaichi’s government has said that Japan has enough oil reserves for the time being, the government is accelerating the resumption of nuclear power generation.
 
Energy has traditionally been the weakest point in Japan’s national security strategy. Japan has said that it attacked Pearl Harbor in 1941 to secure oil in Southeast Asia without U.S. interference. As fuel for power generation shifted from coal to oil in the post-war era, Japan increasingly relied on oil imports from the Middle East. Currently, over 95 percent of imported oil comes from the Middle East, and most of it passes through the Strait of Hormuz.
 
An alternative to oil is nuclear power. Through 2010, Japan had built 54 reactors for nuclear power generation that supplied about 30 percent of all electric power in Japan. In 2011, however, the Great East Japan Earthquake severely damaged the Fukushima Daiichi Nuclear Power Plant when protective structures failed, leading to several deaths and mass evacuations. The event seriously undermined Japan’s energy strategy. The government began to set strict limits for power companies to operate nuclear reactors or construct new ones. 
 
Japan nevertheless took the course of resuming transmission at as many of the existing reactors as possible to secure stable and powerful electricity. The government did not take an alternative course developing renewable energy as European countries had done after the accident in Chernobyl 40 years ago this month.
 
The restart two weeks ago of the Kashiwazaki-Kariwa Nuclear Power Plant is an epoch-making event for energy supply in Japan. Reactor 6 at the plant began its commercial operation on April 16, 2026, for the first time since it paused operations in March 2012. The plant is known as one of the biggest nuclear power plants in the world with seven reactors that have the capacity for 8,212 megawatts of power.
 
The Kashiwazaki-Kariwa plant is owned by Tokyo Electric Power Company (TEPCO), which was responsible for the inadequate defenses of the Fukushima Daiichi Nuclear Power Plant to the 2011 earthquake and for the ensuing deaths and evacuations.  Restarting the plant has been controversial. Although two reactors out of seven passed the examination by the Nuclear Regulation Agency (NRA) in 2017, the NRA issued an order to prohibit their operation in 2021 because of failure to take anti-terrorist measures.
 
The NRA lifted the prohibition order in 2023, and in December 2025, the governor of Niigata, Hideyo Hanazumi, approved resumption of the plant’s operation. TEPCO restarted Reactor 6 in January 2026 but paused the operation at least twice due to an unexpected alarm from a control rod and a leak of electricity on the land surface. Those malfunctions delayed commercial operation of Reactor 6, damaging TEPCO’s credibility. Reactor 7 is expected to start up again in 2029.
 
Even with the restart of Reactor 6, there is no place for nuclear waste to go. Japan has no final disposal site. Mutsu city, Aomori, has an interim storage facility to keep used nuclear fuel until it can be transferred to a nuclear recycling factory, which is planned to be finished in Rokkasho village, Aomori.
 
Although the interim facility in Mutsu was expected to accept 60 metric tons of used nuclear fuel from Kashiwazaki-Kariwa in FY2026, the Governor of Aomori, Soichiro Miyashita, announced that he would not approve any new transfers of used nuclear fuel to the Mutsu facility in FY2026. Miyashita believed it was unpredictable whether the recycling factory in Rokkasho could pass an examination by the NRA. Japan thus has not established a credible recycling system for used nuclear fuel.
 
The government of Japan, meanwhile, is looking for a site to build a final disposal facility somewhere in the country. The government decided in 2000 that nuclear waste from nuclear power plants should be buried underground, a method known as geological disposal, but the government has not decided on a site.
 
To decide on a location, the government must take three steps: a survey of technical literature, a preliminary investigation, and a detailed investigation. The government will grant a two-billion-yen subsidy to a municipality that accepts the literature survey. Another seven billion yen is provided for a preliminary investigation.
 
The government has identified three possible sites: Suttsu Town and Kamoenai Village in Hokkaido, and Genkai Town in Saga. Ogasawara Village, Tokyo, has emerged as a fourth candidate, and the government on April 21 decided to have a literature survey which will take about two years. Although the three earlier candidates voluntarily stepped forward to accept the survey, Ogasawara has left the decision of accepting the survey to the Ministry of Economy, Trade, and Industry (METI). It made the first example to conduct a literature survey with initiative of the national government.
 
METI expects to survey Minamitorishima Island (Marcus Island) in the administrative area of Ogasawara village. Marcus Island is a tiny saucer-like coral atoll with a raised outer rim of between 5 and 9 m (16 and 30 ft) above sea level. It is 2,000 kilometers from mainland Japan.
 
The chief of Ogasawara village, Masaaki Shibuya, has reserved his decision on whether to go forward with a preliminary investigation after the literature survey is finished. There is no one among other three front runners that has decided to proceed to a preliminary investigation. METI is still far from deciding the location for final disposal site, which is needed for operating nuclear power plants in Japan.
 
It is obvious that the effort to build a whole new nuclear power generation system, including a disposal locale for nuclear waste, will not ameliorate the current concerns about energy supply. Construction will take many years. Nevertheless, the government of Japan does not want to stop focusing on nuclear power generation, fearing that it will lose its status as a major economic power in the world.