Kansai Electric Oi Unit 3 Auto-Stops on Generator Field Loss, No Radioactive Impact

Kansai Electric Power announced on the 9th that Unit 3 of its Oi nuclear power plant, which was in operation, automatically stopped at around 11:56 p. m. on the 8th. The unit is located in Oi, Fukui Prefecture. In the incident, a generator issued a "field loss" alarm, indicating a loss of magnetic field. After the generator automatically stopped, the reactor also shut down.

The anomaly occurred in the secondary-system equipment that includes the generator, not in the primary system that cools the reactor. In pressurized-water reactors such as Oi Unit 3, the primary cooling water containing radioactive materials is isolated from the secondary-system water, which normally contains no radioactive substances. It has been confirmed that the fault has caused no radioactive impact on the surrounding environment.

Kansai Electric is investigating the detailed cause, and the restart schedule has not yet been determined. The company said the incident has no impact on the current balance of power supply and demand.