• Computer models did not do a good enough job of quantifying vibration that led to wear on cooling tubes that led to a leak that led to shutting down the San Onofre Nuclear Generating Station's Unit 3 on Jan. 31, the Nuclear Regulatory Commission concludes in an augmented inspection team report.
• In the report, released Thursday, the NRC also cited manufacturing issues as contributing to the events at SONGS,  a 2,200-MW California facility whose other unit, No. 2, already was down for refueling. The station is still offline.
• "[Southern California Edison] identified the most probable causes of the tube-to-tube wear as a combination of higher than predicted thermal/hydraulic conditions and changes in the manufacturing of the Unit 3 steam generators, a conclusion with which the NRC team agreed," The NRC said.

From the article:

"Nuclear Regulatory Commission (NRC) inspectors in a report released July 19 said faulty computer modeling that inadequately predicted conditions in steam generators at the two-unit, 2,200 MW San Onofre Nuclear Generating Station (SONGS) and manufacturing issues contributed to excessive wear of the components." ...