Japan Restarts Nuclear Fleet to Power AI Revolution and Climate Goals
Japan's nuclear revival is accelerating as the country faces mounting pressure to reduce coal dependency whilst supporting energy-hungry AI infrastructure. The Kashiwazaki-Kariwa nuclear plant's Unit 6 reactor restarted on 9 February 2026, marking a pivotal moment in Japan's energy strategy 15 years after the Fukushima disaster.
The restart adds 1.35 gigawatts of capacity to Japan's nuclear fleet, which now comprises 15 operating reactors. This expansion comes as Japan targets nuclear power to supply 20% of its electricity by 2040, up from the current 9%.
Safety Upgrades Lead Nuclear Renaissance
The Kashiwazaki-Kariwa plant exemplifies Japan's commitment to nuclear safety following lessons learned from Fukushima. The facility now boasts a 15-metre tsunami wall, backup power supply vehicles, and advanced filtration systems to prevent radioactive particle release.
Masaki Daito, the plant's deputy superintendent, emphasises the transformation in safety standards. These comprehensive upgrades reflect Japan's position as having implemented some of the world's strictest nuclear regulations.
The restart process remains deliberately cautious. One recent reactor restart faced delays due to earthquake risk assessments, demonstrating Japan's methodical approach to nuclear safety verification.
By The Numbers
- 15 nuclear reactors currently operating with 33 GW combined capacity
- 83 TWh of nuclear electricity generated in 2024, representing 9% of total generation
- 9,500 GWh expected annual output from Kashiwazaki-Kariwa Unit 6
- 92-107 TWh projected nuclear generation for FY2026
- 20% target for nuclear power share by 2040
AI Data Centres Drive Energy Demand
Japan's artificial intelligence ambitions are reshaping energy policy as AI data centres require unprecedented power consumption. Prime Minister Shigeru Ishiba has explicitly linked nuclear revival to AI infrastructure needs, stating that nuclear energy must be utilised to support technological advancement.
"Obviously, nuclear energy needs to be utilised," Prime Minister Shigeru Ishiba acknowledged regarding Japan's AI infrastructure requirements.
The energy-intensive nature of AI processing aligns with broader regional trends in data centre efficiency across Asia. Japan's structured approach to balancing technological growth with energy security reflects the country's principles-led governance framework.
Regional Nuclear Leadership Emerges
Japan's nuclear restart coincides with broader Asia-Pacific developments in nuclear energy. China's small modular reactor deployments and projects in India and Vietnam demonstrate regional commitment to nuclear power as a climate solution.
"Japan's Kashiwazaki-Kariwa restart, China's SMR launch, and India and Vietnam's projects demonstrate that nuclear energy remains essential to the global electricity mix," according to Wood Mackenzie's 2026 energy report.
This nuclear renaissance contrasts with the slower pace of renewable energy deployment. Even optimistic scenarios suggesting renewables could generate 70-80% of Japan's power by 2035 would still require nuclear and gas to fill the remaining capacity gap.
| Energy Source | 2024 Share | 2030 Target | 2040 Goal |
|---|---|---|---|
| Nuclear | 9% | 20-22% | 20% |
| Renewables | 23% | 36-38% | 50% |
| Coal | 32% | 19% | 10% |
| Natural Gas | 34% | 20% | 20% |
Public Scepticism Persists Despite Safety Improvements
The memory of Fukushima continues to influence public opinion on nuclear power. Many Japanese citizens remain concerned about human error risks and the ongoing challenges of decommissioning the damaged Fukushima plant.
Local approval processes reflect this caution, with communities carefully evaluating restart proposals. The Tohoku Electric Onagawa No. 2 reactor faces potential shutdown by end-2026 unless specialised safety facilities are installed, highlighting the stringent requirements reactors must meet.
Engineers continue addressing Fukushima's legacy, working to safely handle highly radioactive fuel and debris. This ongoing challenge serves as a reminder of nuclear power's inherent risks alongside its climate benefits.
Economic and Environmental Imperatives
Japan's nuclear revival addresses multiple challenges simultaneously. The country ranks last among G7 nations in power system decarbonisation according to the E3G think tank, making nuclear expansion crucial for climate goals.
The economic argument remains compelling as well. Post-Fukushima reliance on imported fossil fuels has proven expensive and environmentally damaging. Nuclear power offers a pathway to energy independence whilst supporting Japan's commitment to net-zero emissions.
- Reduced dependence on costly fossil fuel imports
- Lower carbon emissions compared to coal and gas generation
- Stable baseload power to complement intermittent renewables
- Energy security benefits from domestic fuel cycle capabilities
- Economic support for Japan's AI sector growth
How many nuclear reactors does Japan currently operate?
Japan operates 15 nuclear reactors as of February 2026, with a combined capacity of 33 gigawatts. This represents a significant recovery from the post-Fukushima shutdown of all reactors.
What safety improvements have been made since Fukushima?
Key upgrades include 15-metre tsunami walls, backup power systems, advanced filtration for radioactive particles, and implementation of the world's strictest nuclear regulatory standards.
How does nuclear power support Japan's AI ambitions?
AI data centres require massive amounts of stable electricity. Nuclear power provides low-carbon baseload generation that can reliably support energy-intensive AI processing operations without emissions.
What is Japan's nuclear power target for 2040?
Japan aims for nuclear power to supply 20% of total electricity generation by 2040, up from the current 9%, as part of its comprehensive energy security strategy.
Why is public approval still challenging for nuclear restarts?
Fukushima's legacy creates ongoing public concern about safety risks, human error, and waste management. Local communities retain significant influence over restart approvals through consultation processes.
Japan's nuclear renaissance reflects broader shifts in global energy policy as countries balance climate goals with growing electricity demand. The success of Japan's approach could influence nuclear policy decisions across the Asia-Pacific region's diverse energy landscape.
What role do you think nuclear power should play in Asia's clean energy future? Drop your take in the comments below.