Reactor No. 3 at Oi nuclear complex shut down after generator alarm
Kansai Electric Power Company said Reactor No. 3 at the Oi complex in Fukui was shut down around midnight after a generator alarm.
One of the reactors at the Oi nuclear complex in central Japan was shut down overnight after an alarm signalled a problem with a generator, the plant operator said. The announcement was published on August 9, 2026 at 08:36.
Reactor No. 3 at the power station in Fukui Prefecture was taken offline at around midnight, Kansai Electric Power Company said, following the activation of the alarm that indicated an anomaly in the generator system.
"No radioactive leakage has been detected at the nuclear power plant," added the company.
Generator alarms commonly trigger automatic reactor trips or precautionary shutdowns so auxiliary and safety systems can be checked; operators typically move to stabilise the unit and confirm that cooling and containment systems remain fully functional.
Kansai Electric did not immediately provide further details about the precise cause of the alarm or an estimated timetable for restarting the reactor. Company engineers and plant technicians were reported to be carrying out inspections and diagnostics.
Local regulators and the operator said they would continue to monitor the site and issue updates if new information emerges.
Photo: press material from the event
