Japan has suspended operations at the Kashiwazaki-Kariwa Nuclear Power Plant; the world’s largest by capacity—less than a day after it was brought back online. The shutdown occurred on Thursday following an alarm that sounded during reactor start-up procedures, marking a significant setback in Tokyo Electric Power Company’s (Tepco) efforts to revive the facility.
Okay News reports that Tepco spokesperson Takashi Kobayashi confirmed the suspension, stating that the reactor remains “stable” and there has been “no radioactive impact outside” the facility. The operator is currently investigating the cause of the alarm and has not provided a timeline for when operations might resume.
The incident affects Reactor Number 6, which had only just restarted on Wednesday after a separate alarm malfunction delayed its initial launch from Tuesday. This restart was a milestone event, representing the first time the plant had generated power since the devastating 2011 Fukushima disaster led to a nationwide shutdown of all nuclear reactors.
The restart of the Kashiwazaki-Kariwa plant has been a contentious issue. While the government views the revival of nuclear power as essential for meeting its goal of net-zero emissions by 2050, the move has faced significant opposition. Local residents and activists have staged protests outside Tepco’s headquarters and the Niigata prefectural assembly, citing lingering safety concerns from the 2011 meltdown.
Despite the suspension, Reactor Number 6 was scheduled to begin commercial operations next month. Meanwhile, the plant’s seventh reactor is not expected to come back online until 2030, and the remaining five reactors face potential decommissioning, meaning the facility is operating at a fraction of its original capacity.