Overview 

Japan’s seventh Strategic Energy Plan (SEP), approved by the Cabinet in February 2025, officially declared, for the first time since the 2011 Fukushima nuclear accident, a policy to increase Japan’s civil nuclear power. Former Prime Minister Kishida’s declaration of a so-called “nuclear comeback” in 2023 (which was then met with surprise) has been enshrined by this latest SEP, which gives the green light to ramp up civil nuclear power through the construction of new nuclear power plants and renovating existing plants. This will have a major impact on Japan’s energy industry.

In a country with extremely limited energy resources (Japan imports close to 90 percent of its energy), nuclear operators and the Government of Japan (GOJ) have worked hard since the Fukushima accident to promote the restart of nuclear power plants and revitalization of the country’s nuclear industry. However, resistance from Japanese citizens and strict regulations such as those passed by Japan’s Nuclear Regulation Authority (NRA) have slowed those efforts. The NRA was established after the Fukushima nuclear accident and has defined itself as having the strictest inspection standards in the world. Even Japan’s major electric power companies and other energy industry players have criticized the NRA’s inspection standards and methods as unreasonable and too strict. 

Over the past two years, Japan’s energy usage forecasts have shifted from an expected decline due to an aging population to a predicted increase of six percent over the next ten years, due to the rapid increase of data centers and the construction of new semiconductor factories, reflecting the growing demand for cloud computing and the proliferation of artificial intelligence. Some operators, such as Tokyo Electric Power Company (TEPCO)’s President Kobayakawa, now believe that the potential for growth in domestic electricity demand is “close to the period of high economic growth” from 1960s &1970s Japan.

Table: Japan’s Electricity Generation, 2019-2023 (Units: Terawatt-hour (TWh) 

Source: Japanese Ministry of Economy, Trade, and Industry

Japan’s national policy aims to reduce greenhouse gas emissions by 46% by fiscal 2030 (base 2013 levels) and achieve carbon neutrality by 2050; nuclear power is an extremely promising source of carbon-free power to meet those goals. Nuclear power has distinct advantages to many renewable energy sources (e.g., solar, wind), which are not ideal as baseload power sources. Increasing Japan’s nuclear output will require restarting reactors that have been shut down for over a decade, replacing old reactors that have been slated for decommissioning, and moving forward with the construction of new reactors with improved safety measures. The trend in favor of civil nuclear power may be observed in the following recent developments:

• The Governor in Niigata Prefecture is expected to approve the restart of the Unit Six Reactor (1.4 GW) at the TEPCO’s Kashiwazaki-Kariwa Nuclear Power Plant after the fall of 2025 (May 2025).
• Tohoku Electric Power Company (EPC) resumed commercial operation of Unit Two Reactors (0.8 GW) at its Onagawa Nuclear Power Plant for the first time since the 2011 Fukushima earthquake and tsunami (December 2024).
• The tsunami risk assessment for the restart of Chubu EPC’s Unit Three (1.1 GW) and Unit Four (1.14 GW) Reactors at Hamaoka Nuclear Power Plant, which had been a major hurdle for the restart, was approved by the NRA.  After 10 years of review, the utility can now move on to the next stage of “safety measure for the facility” (November 2024).
• The Kyushu EPC announced that it will consider the development and installation of next-generation innovative reactors in the Kyushu region in its management vision for 2035 (May 2025).
• TEPCO announced that the amount of contaminated water generated at the Fukushima Daiichi Nuclear Power Plant in fiscal 2024 was reduced to 70 tons per day, a decrease of approximately 10 tons from the previous year.

Moving forward with restarts, rebuilds, and new construction will also require the decommissioning of aging nuclear power plants. American companies are not typically involved in decommissioning projects as primary contractors, and their presence is relatively unknown and rarely reported in the media. However, a number of U.S. decommissioning companies have signed contracts or are currently in negotiations with Japan’s major nuclear engineering companies and electric power companies, which own and operate the country’s nuclear power plants. Furthermore, according to industry insiders, the market share of U.S.-made goods and services used in the Japanese nuclear sector well exceeds that of other non-Japanese products/services, making U.S. products/services indispensable to Japanese civil nuclear power companies.

Regarding next-generation nuclear technology, large advanced light water reactors (conventional types with added safety features) are the most likely to replace conventional large light water reactors. Although not yet commercially viable, small modular reactors (SMRs) and fusion reactors are also being examined by the GOJ and power companies.

Leading Sub-sectors 

The following are the three leading sub-sectors in Japan’s civil nuclear power industry: (1) Restart of existing nuclear plants; (2) Decommissioning and Decontamination of Fukushima Daiichi Nuclear Power Station and other non-accident commercial reactors; and (3) Next-generation reactor technologies, including SMRs. 

Nuclear Restarts  

Ten electric power companies (EPCs) own all 33 operable commercial nuclear reactors in Japan. At present, the EPCs have submitted the necessary applications to the NRA, to restart 25 reactors. Of the 25 reactors, 14 had resumed operations as of May 12, 2025, the latest being Shimane Unit Two (0.8 GW), which restarted in January 2025, and is owned by Chugoku EPC. Of the remaining 11 reactors, the NRA has approved four for restart: Tokai No.2 Power Station (1.1 GW) owned by the Japan Atomic Power Station (JAPC); Tomari Unit Three (0.9 GW) owned by Hokkaido EPC; and Kashiwazaki-Kariwa Unit Six and Seven (1.4 GW each) owned by TEPCO. NRA has denied one: Unit Two (1.2 GW) at Tsuruga Power Station owned by JAPC; and is reviewing six: Tomari Unit One and Two (0.6 GW each) owned by Hokkaido EPC; Higashidori Unit One (1.1 GW) owned by Tohoku EPC; Hamaoka Unit Three and Four (1.1 GW each) owned by Chubu EPC; and Shiga Unit Two (1.2 GW) owned by Hokuriku EPC. The Commercial Service (CS) Japan engages with all of Japan’s EPCs to obtain updates on their general procurement policies and specific products or technologies of interest (please see Opportunities section).

Nuclear Decommissioning and Decontamination (D&D) 

1. Fukushima Daiichi Nuclear Power Station 

Tokyo Electric Power Company Holdings (TEPCO) oversees the decommissioning of the four damaged Fukushima Daiichi reactors in Fukushima province. This complex and long-term (estimated at 40 years) project includes treatment of radioactive water, removal of nuclear fuel debris and spent nuclear fuels, management of radiological waste, and ultimately demolishing the facilities. 

Removing the fuel and fuel debris in Units One, Two, and Three is a complex undertaking, and still an uncharted area for the domestic and international civil nuclear communities. In November 2024, the first trial removal of “fuel debris” of only 0.7 grams from the Unit Two reactor was successfully accomplished. The purpose of this trial was to experimentally collect a tiny debris to strategize the entire debris removal operation. TEPCO must remove a total of 880 tons of debris, including highly radioactive material produced by the nuclear fission of uranium fuel. This is the most challenging step in decommissioning the plant. TEPCO, the International Research Institute for Nuclear Decommissioning (IRID), and Mitsubishi Heavy Industries (MHI) jointly developed the telescopic device and the robotic arms specifically for these efforts. 

In this ongoing, 40-year project, to date, U.S. firms have already contributed products and technologies in areas including water treatment and the removal of spent nuclear fuels and rubbles. American firms have also been successful in offering unique U.S. waste management and robotic technologies. CS Japan is in close contact with TEPCO and can assist with efforts concerning U.S. solutions related to Fukushima D&D.  

2. D&D of Non-Accident Commercial Reactors  

As of May 2025, 18 non-accident, shutdown reactors are being decommissioned, with an average estimated cost of $278 to $395 million (depending on the size of the reactors). Generally, domestic reactor vendors Toshiba, MHI, and Hitachi, as well as major engineering firms or general contractors, serve as the prime contractors to Japanese EPCs. Some U.S. firms, however, have had success directly working with Japanese EPCs. As such, the scope of D&D projects may be expanded to include the removal of contaminated metals to make space for the primary mission of electricity production. The Commerical Service Japan believes that U.S. firms can be an integrated partner, successfully completing Japanese D&D projects to lay the ground for new nuclear projects on existing sites.

Although Japan has traditionally been slow to adopt U.S. project management expertise that could minimize costs and shorten project timelines while adhering to relevant safety measures, U.S. products and technologies are both highly regarded and in high demand. CS Japan is in close contact with all nuclear EPCs and is ready to assist with the promotion of U.S. products and technologies that could contribute to the D&D of non-accident shutdown reactors. 
 

Next-Generation Innovative Reactors and Small Modular Reactors

At the Third Nuclear Supply Chain Symposium held in March 2025, the Ministry of Economy, Trade and Industry (METI), the University of Tokyo, and the Federation of Electric Power Companies of Japan (FEPC) said that, even if all of Japan’s existing nuclear power plants are operated for the maximum 60 years, the country will see a significant aggregate decrease in installed capacities (kW) after 2035 (i.e., 3.6 GW by 2040 and 14 GW by 2050, respectively). Considering that the typical lead time for the construction of a nuclear plant is about 20 years, all three organizations agreed that it is imperative to develop and install next-generation innovative reactors to secure the kilowatt capacities of nuclear power in the future.

The FEPC further noted that while development of innovative reactors is being led by manufacturers, EPCs should work alongside them on design to address key features such as operation, maintenance, and decommissioning. Also, the FEPC noted that it is important to standardize plant designs to unify specifications and to ensure the stable procurement of components by incorporating more generic products. Lastly, the FEPC noted that it is necessary to develop a good regulatory framework for innovative reactors, including having an active dialogue with the NRA. 

Japan wants to maintain and develop its domestic nuclear technologies and expand its own new reactor models into international markets. EPCs believe the time has come for them and nuclear suppliers to work together on developing new innovative reactors. With this in mind, Japan aims to begin commercial operations of next-generation innovative reactors between 2030 and 2040. Innovative Light-Water Reactors (ILWR), which are based on existing light-water technologies but incorporate improved safety and reliability functionalities, are currently the most favored reactor in Japan. The Hokkaido, Kansai, Shikoku, and Kyushu EPCs are jointly standardizing the plant development of MHI’s Pressured Water Reactor version of ILWR, “SRZ-1200”, with an output of 1.2 GW. The basic design of the standard plant has been largely completed, with a view to commercial operation in the mid-2030s. The EPCs will move onto the detailed design phase if they decide to introduce SRZ-1200, and since December 2024, they have been exchanging opinions with the NRA regarding new regulations.

High-Temperature Gas-cooled Reactors (HTGRs), considered to be more efficient and safer than conventional nuclear power plants, are also gaining interest in Japan. Detailed design for a GOJ-led (in coordination with Mitsubishi Heavy Industries and the Japan Atomic Energy Agency (JAEA) acting as manufacturer and operator, respectively) demonstration reactor will be completed by 2030, when the operating business will be established. Obtaining the license, construction and installation of HTGR will be completed by the end of 2030s, and the operation is due to begin. In June 2025, Ibaraki Prefecture submitted a request to the GOJ for the establishment of the demonstration reactor.

Conceptual Research and Development (R&D) of a Fast Reactor is also currently under way; the fuel technology will be specifically considered by MHI and JAEA around FY 2026. The basic design of a demonstration Fast Reactor is scheduled to begin in 2028, with operation expected to begin in the mid-2040s.

The basic design of Small Modular Reactors (SMR), which is regarded as “easy-to-use” and receives inquiries from regions where relatively small grids are installed, is expected to begin in FY 2027 and become operational in the early 2040s. In November 2024, the Chubu EPC acquired an interest in a U.S. developer of SMR, NuScale Power Corporation. In the afore-mentioned Symposium, Chubu noted the reason of becoming an owner of NuScale as “promoting R&D and demonstration through international collaboration” as well as “with the future business expansion of NuScale, Chubu aims to secure and expand its revenue base and ensure all options for the sustainable use of nuclear power generation”.

The GOJ is also in discussions with industry associations, business associations, investors, and academic experts (chaired by Tokyo University), about the possibility of building a prototype Fusion Reactor, beginning with manufacturing design and construction in/around 2030. Aomori Prefecture has indicated its interest in hosting the plant. Several other Japanese ventures are seeking to develop fusion power demonstrations in the 2030s, and discussions between Japan’s government and academia are underway regarding the locations and safety measures. In the meantime, the GOJ summarized its fusion safety regulation policy for the first time in March 2025.

All U.S. advanced reactor technologies are well positioned to capture a significant share of the future Japanese market for next-generation nuclear power generation. After successful advocacy and engagement with the GOJ and major Japanese nuclear companies, several U.S. nuclear companies were awarded Japan’s national feasibility study proposals for an advanced nuclear power plant, including SMR. Japan also aims to support local suppliers’ participation in U.S. and European SMR projects. 

Opportunities 

• Chubu Electric Power Company’s FY2025 major procurement items on nuclear power generation facilities can be referenced at the following website:  Nuclear Power Generation Facilities
   
• Chugoku Electric Power Company lists the components and services related to nuclear power plants in FY 2025 at the following website: The Chugoku Electric Power Co., Inc. Main Material and Equipment Procurement Plan (energia.co.jp) 
   
• Electric Power Development Co., Ltd. (J-Power) has a general product procurement guideline and major procurement items at the following website: Product Procurement | J-POWER (jpower.co.jp)
   
• Hokkaido Electric Power Company lists its major procurement items regarding the nuclear power plants at the following website: Major Procurement Items: Procurement of Materials and Equipment, Hokkaido Electric Power Co.,Inc. (hepco.co.jp)
   
• Hokuriku Electric Power Company lists the company’s items of procurement, which include products and technologies related to nuclear power plants. Items of Procurement (Procurement Activities) | Hokuriku Electric Power Company (rikuden.co.jp) 
   
• The Kansai Electric Power Company disclosed its latest 2024 procurement plan, which includes nuclear power plant materials and equipment. See the Main Procurement Plan in Fiscal 2024 [KEPCO]
   
• Kyushu Electric Power Company’s most recent FY 2024 procurement plan, including equipment and materials for nuclear power stations, can be referenced at the following website: 九州電力　Procurement Plan (kyuden.co.jp)
   
• Shikoku Electric Power Company’s major items of procurement, including those related to nuclear power plants in FY 2025, can be referenced at the following website: Major Items of Procurement | Shikoku Electric Power Co., Inc. (yonden.co.jp) 
   
• Tohoku Electric Power Company’s website references the recent major procurement items, including nuclear power facilities, at the following website: Materials and Equipment to be Procured in Recent Years - Tohoku Electric Power Co., Inc.
   
• TEPCO releases its procurement plan each year, which also includes that of nuclear power equipment. The company’s FY 2025 procurement plan can be accessed at Procurement Plan | TEPCO. 

 Resources

1. The 40^th New Orleans Association (NOA) Conference (Tokyo, May 2026): CS Japan will hold its an annual one-on-one matchmaking business event, where international procurement managers from all of Japan’s regional EPCs (Hokkaido, Tohoku, Hokuriku, Chubu, Tokyo, Kansai, Shikoku, Chugoku, Kyushu, Okinawa EPCs, J-Power, and Japan Atomic Power Company) will gather to meet with U.S. suppliers. Dates will be announced in January 2026. Please refer to the last Conference details on the website: Japan Trade Events 
    
2. The 9^th International Forum on the Decommissioning of the Fukushima Daiichi Nuclear Power Station (August 3 & 4, 2025 in Fukushima Prefecture) is organized by Nuclear Damage Compensation and Decommissioning Facilitation Corporation. To register:  Let’s talk about Fukushima Daiichi Decommisioning | The 9th International Forum on the Decommissioning of the Fukushima Daiichi Nuclear Power Station
    
3. Tsuruga International Symposium 2025 (early or middle November 2025 in Fukui Prefecture) is organized by the Ministry of Education, Culture, Sports, Science, and Technology, GOJ. The event focuses on research & development reactors belonging to Japan Atomic Energy Agency. 

Commercial Service Japan Contact 

For additional information about Japan’s civil nuclear power business sector, please contact Commercial Service Japan (CS Japan) at Office.Tokyo@trade.gov or Mr. Takahiko Suzuki at Takahiko.Suzuki@trade.gov