Kansai Electric Power announced the causes of the shutdowns of Oi Nuclear Power Station Unit 3 and Mihama Nuclear Power Station Unit 3, as well as measures to prevent a recurrence. The timing of future restarts remains undecided.
Kansai Electric Power announced the causes of the shutdowns of Oi Nuclear Power Station Unit 3 and Mihama Nuclear Power Station Unit 3, along with measures to prevent a recurrence. At Oi, the cause was an abnormality in equipment that generates a magnetic field. The company explained that a short circuit occurred due to a missing component and the effects of dust inside the equipment.
As recurrence-prevention measures, the magnetic-field generating equipment will be replaced and insulating resin applied to ensure the heat sink’s insulation. Periodic inspections will begin on 10 October, but the timing of the restart remains undecided.
At Mihama Unit 3, the company explained that rainwater entered after part of the cover over the piping was installed upside down, causing corrosion and creating a hole. The same installation issue is said to have occurred when the cover and insulation were replaced during outdoor work in 2010.
As a recurrence-prevention measure, the piping material will be changed from carbon steel to stainless steel, and the cover and insulation will be replaced with new ones. The manual will also include precautions concerning the direction in which the cover is installed.