Japan Bets Big on Nuclear Power With Plan to Rebuild Dozens of Reactors by 2050

Japan needs to rebuild between two to five ageing nuclear reactors by the 2040s and about 11 to 14 by 2050, adding up to 16 gigawatts (GW) of generational capacity, to secure a stable power supply, the Ministry of Economy, Trade and Industry (METI), proposed on Friday, at a nuclear policy meeting.

The proposal, presented at a nuclear policy meeting, reflects a shift toward greater reliance on atomic energy to meet rising power demand driven by artificial intelligence data centres and to reduce costly fossil fuel imports, which currently account for 60-70% of Japan’s electricity generation.

The plan marks the latest and most concrete step in Japan’s decade-long pivot back toward nuclear power after the 2011 Fukushima Daiichi meltdown. The incident triggered the shutdown of all 54 of the country’s operating reactors and a sweeping public rejection of atomic energy.

The government at the time even set a goal to phase out all nuclear power plants by 2040, placing a 40-year lifespan on reactors and limiting construction of new plants.

Before the 2011 disaster, nuclear reactors generated approximately 30% of Japan’s electricity. As of 2024, nuclear accounted for less than 10% of the same. Even this low figure was the highest it had been for a decade. The METI proposal directly addresses the gap that will emerge as Japan’s existing fleet of reactors approaches the end of its operational lifespan, a problem that restarts of idled plants alone cannot solve.

The proposal comes at a time when Japan faces a structural electricity challenge with no straightforward solution. Electricity demand, which has been declining for decades as Japan’s population shrank and its economy matured, is now projected to increase sharply as AI data centres, semiconductor manufacturing and electrification of transport all accelerate simultaneously. Japan’s latest strategic energy plan, adopted in 2025, targets nuclear at 20% of the electricity mix by fiscal 2040, doubling its current share, and renewables at 40-50%, while reducing coal-fired power from nearly 70% to between 30% and 40%.

The 14 new nuclear power plants would have a combined capacity of approximately 16 GW. By setting concrete replacement targets, the government aims to improve predictability for utilities, which have faced significant uncertainty about whether capital investments in new nuclear construction would be recoverable.

Of the 33 units that remain operable in Japan, 15 have been restarted since the post-Fukushima shutdowns. However, many of these reactors are approaching or exceeding their 60-year operational lifespans, raising concerns about a future decline in nuclear capacity even if restarts of idled plants continue.

The most recent restart came on Feb. 9, 2026, when Japan reactivated Unit 6 of the Kashiwazaki-Kariwa Nuclear Power Station in Niigata Prefecture, the country’s largest nuclear facility. With a capacity of 1,356 megawatts, Unit 6 could displace approximately 1.3 million tonnes of Liquefied Natural Gas (LNG), or 62 billion cubic feet of natural gas imports annually, based on Japanese government estimates.

Prime Minister Sanae Takaichi, one of Japan’s longest-standing advocates for nuclear power, has said the energy source is needed to deal with the increase in electricity consumption, especially by energy-hungry data centres. She has emphasized the restart of ageing reactors and the development of next-generation technologies including nuclear fusion, to make Japan 100% energy self-sufficient.

Recent technological developments, including the proliferation of AI and data centres, have led Japanese government forecasts to project power demand increasing 1.4 times compared to 2019 levels, reaching as high as 1.25 trillion kilowatt-hours by 2050. These projections, along with shifting public opinion and energy security concerns, have driven a fundamental policy reversal from reducing reliance on nuclear power to actively promoting new nuclear construction and restarts.

Nuclear power plant construction has become significantly more expensive globally, which casts doubt on whether all 14 planned reactors will ultimately be built. Cost overruns at nuclear projects in Europe and the United States over the past decade have demonstrated the difficulty of delivering new nuclear capacity on a budget, even in advanced economies with mature regulatory frameworks.

Moreover, restarting Japan’s nuclear reactors has continued to be hampered by periodic delays and setbacks as of March 2026, even where regulatory approvals have been obtained.

Under the current energy plan, Japan aims to double the share of nuclear power in its ​electricity generation to around 20% by fiscal 2040. Takaichi is a strong proponent for increasing nuclear power, seeking to ease the bill for imported coal, gas and oil, which fuel 60-70% ⁠of Japan’s power generation.

Public trust in nuclear energy has yet ​to fully recover following safety concerns and recent controversies, including Chubu Electric’s falsified seismic risk assessments for its Hamaoka nuclear plant.