Automatic Shutdown of Unit 3 at Oi Nuclear Power Plant During Operation; Kansai Electric Power to Investigate Cause from the 12th

Unit 3 of the Oi Nuclear Power Plant in Fukui Prefecture, Japan, experienced an automatic shutdown during operation in the early hours of the 9th. Operator Kansai Electric Power stated that the fault is related to an internal abnormality in the generator and plans to formally begin a cause investigation from the 12th. Currently, there is no clear timeline for when the unit can resume operation.

According to reports, an alarm related to "loss of magnetic field" occurred inside the generator used for power generation at the time of the incident, after which the generator stopped, and the reactor in operation also automatically shut down. On the 10th, Kansai Electric Power visited the Fukui Prefectural Government to apologize for the fault and report on subsequent response measures.

Yuichiro Sakamoto, head of the Fukui Prefecture Disaster Prevention and Safety Division, pointed out that following a steam leak fault at Mihama Nuclear Power Plant Unit 3 in May this year, an unexpected emergency shutdown of a reactor in operation occurring within a short period may undermine public trust in nuclear safety. Local government authorities have demanded that the operator promptly identify the cause and implement measures to prevent similar issues from recurring.

Kansai Electric Power stated that it will conduct a full-scale investigation of the generator and related equipment after the 12th to confirm the specific mechanisms behind the alarm trigger and automatic shutdown. As for whether the unit can resume operation before the scheduled periodic inspection in October, the company said it is currently unable to determine, and a decision will be made based on investigation results and safety confirmation.