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Operations suspended at Kashiwazaki-Kariwa plant
Japan's Tokyo Electric Power Company (Tepco) has temporarily stopped operations at the Kashiwazaki-Kariwa nuclear power plant, the world's largest, just hours after restarting one of its reactors. The suspension followed an alarm triggered during start-up procedures on Thursday, though Tepco confirmed the reactor remained stable and posed no radiation risk to the surrounding area.
Delayed restart and safety concerns
Reactor number six at the plant, located northwest of Tokyo, was restarted on Wednesday-one day later than scheduled due to an earlier alarm malfunction. This marked the first reactor to come online at the facility since the 2011 Fukushima disaster, which led to the shutdown of all 54 of Japan's nuclear reactors at the time.
The 2011 catastrophe, triggered by a 9.0-magnitude earthquake, resulted in a meltdown at the Fukushima plant and forced over 150,000 residents to evacuate. Despite subsequent safety assurances, many have not returned to their homes.
Investigation underway as protests persist
Tepco spokesperson Takashi Kobayashi stated that the reactor was stable and that there was "no radioactive impact outside" the plant. However, the company is now investigating the cause of the alarm and has not provided a timeline for resuming operations.
The restart of reactor number six had already faced opposition from local residents, with small protests outside Tepco's headquarters last week and larger demonstrations near the Niigata prefectural assembly in December. Critics argue that safety concerns remain unaddressed.
Future of the plant and Japan's nuclear ambitions
The Kashiwazaki-Kariwa plant, once fully operational with seven reactors, will see a significant reduction in capacity. Reactor number seven is not expected to restart until 2030, while the remaining five may be decommissioned entirely.
Before the Fukushima disaster, nuclear power accounted for nearly 30% of Japan's electricity, with plans to increase that share to 50% by 2030. Since the shutdown, Japan has struggled to revive its nuclear sector as part of its broader goal to achieve net-zero emissions by 2050. To date, 15 of the country's 33 operable reactors have been restarted since 2015.
Next steps
Tepco has not indicated when reactor number six might resume operations, pending the outcome of its investigation. The reactor was initially set to begin commercial operations next month.
