Japan Halts Operations at World's Largest Nuclear Plant Following Restart

Fri Jan 23 2026 03:52:05 GMT+0200 (Eastern European Standard Time)

Japan's Kashiwazaki-Kariwa Nuclear Power Plant, the largest globally, was suspended mere hours after a restart due to an alarm during reactor procedures. This incident raises concerns about safety and the future of nuclear energy in the country.

Japan's Kashiwazaki-Kariwa Nuclear Power Plant, the world's largest nuclear facility, was shut down just hours after being restarted. The shutdown occurred during procedural alarms, despite assurances from operator Tepco that the reactor remained stable. This facility is the first to start operations since the catastrophic Fukushima disaster in 2011, prompting ongoing scrutiny and protests from local residents about safety concerns. As Japan aims to shift towards renewable energy and achieve net-zero emissions by 2050, the future of its nuclear power strategy remains uncertain amidst these challenges.

Japan has suspended operations at the world's largest nuclear power plant, hours after its restart, its operator has said.

An alarm sounded during reactor-start-up procedures at Kashiwazaki-Kariwa in Tokyo, but the reactor remained stable, Tokyo Electric Power Company (Tepco) spokesperson Takashi Kobayashi stated.

Reactor number six restarted on Wednesday, a day later than planned due to an alarm malfunction - being the first at the plant to be turned on since the 2011 Fukushima disaster.

Following the catastrophic events at Fukushima, all 54 of Japan's reactors were shut down after a 9.0 magnitude earthquake led to a meltdown, prompting one of the worst nuclear disasters in history. Over 150,000 people were evacuated from their homes, many of whom have not returned despite government assurances of safety.

After the suspension of reactor number six on Thursday, Tepco's Kobayashi assured that it was stable and there is no radioactive impact outside.

The reactor was initially scheduled to start on Tuesday, but its start was delayed due to technical issues and it is now anticipated to begin commercial operations next month.

Kobayashi noted that Tepco is currently investigating the cause of the incident and did not specify when operations would resume.

The seventh reactor at Kashiwazaki-Kariwa is not expected to restart until 2030, and the future of the other five remains uncertain, potentially leading to a significant reduction in the plant's capacity compared to when all seven reactors were operational.

Despite safety concerns raised by local residents, reactor number six was allowed to restart. Last week, protests occurred outside Tepco's headquarters and the Niigata prefectural assembly, reflecting growing public sentiment against nuclear power in Japan.

Before the Fukushima disaster, nuclear power contributed to nearly 30% of Japan's electricity, with plans aimed to increase this share to 50% by 2030. Following years of shutdowns, Japan has managed to restart 15 of its 33 operable reactors while gearing towards net-zero emissions by 2050.