Kansai Electric Power announced that Ohi Nuclear Power Plant Unit 3 automatically shut down at around 11:56 p.m. on the 8th. The generator shut down after a loss-of-excitation alarm was triggered, followed by a shutdown of the reactor. The company said there was no radiological impact on the surrounding environment.
Kansai Electric Power announced that Ohi Nuclear Power Plant Unit 3 in Oi, Fukui Prefecture, automatically shut down at around 11:56 p.m. on the 8th. An alarm indicating a loss of excitation, meaning that the generator's magnetic field had been lost, was triggered, and the reactor also shut down as a result of the generator's automatic shutdown.
The abnormality occurred in secondary-side equipment, including the generator, rather than in the primary system that cools the reactor. The secondary system normally does not contain radioactive materials. The company said there was no radiological impact on the surrounding environment from the incident at this time.
Kansai Electric is investigating the detailed cause, and the timing of the resumption of operations has not been determined. The incident is not believed to have affected the current balance between electricity supply and demand.