U.S. Nuclear Power Plants Already Closed or Closing

[JayhawkSD]

3. Not a particularly accurate description.

"Unit 2 was taken offline in January 2012 for a planned outage. Unit 3 was taken offline at the end of the month after station operators detected a leak in a steam generator tube. Inspections of both units found the tubes were vibrating in generators in both units. Mitsubishi Heavy Industries had replaced all of the steam generators. Southern California Edison decided to focus on finding replacement generation instead of spending money on long-term repair and restart costs."

Steam generators were replaced at the end of their normal life spans. Southern California Edison called for a redesign of tube arrangement, eliminating tube support plates in order to add a few more tubes, to achieve increase in energy production of less than 3%. It turned out the support plates were actually supporting the tubes (wow, who could have guessed that?) and preventing them from vibrating and rubbing against each other. In the process of rubbing against each other without the support plates, they were rubbing holes in the tubes.

Utterly predictable design error, which is why Westinghouse had put the support plates there in the original steam generators. Lack of the support plates rendered the steam generators unusable. Due to Southern California Edison having approved the redesign, Mitsubishi Heavy Industries could not be held liable for the error.