Investigation into Automatic Shutdown of Unit 3 at Japan's Ohi Nuclear Power Plant: Damage Found in Exciter Rotating Rectifier
Kansai Electric Power reported on August 19 that Unit 3 of the Ohi Nuclear Power Plant experienced an automatic generator trip triggered by a generator loss-of-field alarm at 23:56 on August 8, followed by an automatic reactor shutdown. At the time of the event, the unit was operating stably at rated thermal power. The company stated that the event caused no radiological impact on the environment. The loss-of-field alarm is used to indicate an abnormal state in the magnetic field generated inside the generator. Following the incident, Kansai Electric conducted on-site inspections of equipment related to generator magnetic field establishment, including the generator, exciter, and automatic voltage regulator (AVR). Among these, the exciter is used to establish the magnetic field for the generator...
2026-08-19
