World's Largest Nuclear Plant Edges Closer to Restart as Local Approval Granted

Japanese local authorities have officially approved the restart of the Kashiwazaki-Kariwa nuclear power plant, the world's largest, marking a pivotal moment for Japan's energy future. This decision, announced on Friday, November 21, 2025, is the first such approval for the facility since the devastating 2011 Fukushima disaster.

Niigata province Governor Hideyo Hanazumi granted the green light for the plant's resumption, a significant step towards Japan's broader goal of revitalizing its nuclear sector. The governor's decision follows extensive deliberation and addresses the critical need to reduce the nation's reliance on imported fossil fuels.

This move is central to Japan's ambitious targets for achieving carbon neutrality by 2050 and ensuring energy security amidst rising global demand, particularly from sectors like artificial intelligence and semiconductors, as reported by energynews.pro. The plant's operator, Tokyo Electric Power Company (Tepco), still requires final permission from Japan's national nuclear regulator.

Governor Hanazumi stated at a briefing that it would be difficult to halt a facility that has passed national regulatory standards without rational reason, according to Bloomberg. He is expected to seek a vote of confidence from the prefectural assembly on his decision, with sessions beginning December 2.

The approval specifically targets the partial resumption of operations, with Reactor No. 6 being the primary focus for restart. Kyodo News reported that this reactor could become operational by March 2026, following the necessary pre-service checks and regulatory clearances.

For Tepco, the restart of Kashiwazaki-Kariwa represents a crucial financial opportunity, potentially boosting annual net profits by ¥100 billion, as noted by The Japan Times. This revenue is vital for the company, which continues to manage the immense costs associated with the Fukushima Daiichi decommissioning efforts.

This development underscores Japan's evolving energy policy, which increasingly views nuclear power as an indispensable component for a stable, low-carbon energy supply. The government aims for nuclear power to contribute 20-22% of the electricity mix by 2030, according to Mark & Spark Solutions.

• Post-Fukushima Shift and Energy Security Imperatives: Following the 2011 Fukushima disaster, Japan idled all its nuclear reactors, leading to a significant increase in fossil fuel imports. However, the resource-poor nation has gradually shifted its stance, with 14 reactors already resuming operation under stricter safety standards, as reported by rnz News. The current push for Kashiwazaki-Kariwa's restart is driven by a renewed focus on energy security and reducing vulnerability to global energy market fluctuations.
• Tepco's Path to Re-approval and Safety Concerns: Tepco, the operator of both Fukushima Daiichi and Kashiwazaki-Kariwa, has faced intense scrutiny. While the Nuclear Regulation Authority (NRA) granted initial approval for units 6 and 7 in 2017, the plant's license was restricted in 2021 due to security system failures, including access control issues, according to energynews.pro. This operational freeze was only lifted in late 2023 after extensive inspections and improvements.
• Local Sentiment and Economic Incentives: Public opinion in Niigata Prefecture remains divided. A survey conducted by the prefectural government in early November 2025 indicated that 61% of residents within a 30-kilometer radius did not believe conditions for restart had been met, The Japan Times reported. To garner local support, Tepco has pledged approximately ¥100 billion ($644 million) to support local communities, a move some critics have labeled as "bribery," according to the South China Morning Post.
• Regulatory Hurdles and Technical Preparations: While Governor Hanazumi's approval removes a major local hurdle, the plant still requires final permission from the national Nuclear Regulation Authority. Technical preparations for Reactor No. 6, including fuel loading, were completed in October 2025, as confirmed by The Japan Times. The NRA's continuous oversight and strict requirements ensure ongoing safety inspections before full reactivation.
• Broader Implications for Japan's Energy Mix: The restart of Kashiwazaki-Kariwa aligns with Japan's updated energy strategy, which aims for nuclear power to provide 20-22% of its electricity by 2030, a significant increase from 5.6% in 2022, according to the Atlantic Council. This shift is crucial for meeting carbon reduction targets and stabilizing electricity prices by reducing reliance on imported liquefied natural gas (LNG).
• Technological Upgrades and Future Outlook: The Kashiwazaki-Kariwa plant has undergone substantial safety upgrades since 2011, including the construction of a 15-meter tsunami wall and new power backup systems on higher ground, RNZ News reported. If Reactor No. 6 restarts as anticipated by March 2026, it would be the first Tepco reactor to come online since the Fukushima accident, setting a precedent for further restarts and potentially influencing the construction of new reactors in Japan.