CHILLING TESTIMONY: DESIGN FLAWS AT CALIFORNIA NUCLEAR PLANT PUT MILLIONS IN DANGER

San Onofre nuclear power plant - inhabitat.com

The operator of the San Onofre nuclear power plant in Southern California made critical errors in the design of the plant's replacement steam generators and, as a result, the public was put in great danger last year, according to expert testimony Wednesday by an internationally renowned nuclear engineer at a Nuclear Regulatory Commission (NRC) hearing.

The chilling testimony, which was presented to the NRC Petitions Review Board, was accompanied by evidence showing that plant operator Southern California Edison should have been required to go through a license amendment process before installing the new steam generators in 2009 and 2010.

The nuclear expert, Arnie Gundersen, a consultant to Friends of the Earth, explained to the NRC that the design changes proposed by Edison created a dangerously high level of steam at the top of all four replacement steam generators. These changes created conditions causing vibration that a year ago led to severe damage to the thousands of tubes inside the steam generators in both San Onofre reactors. 

As a result, some of the radioactive steam was released into the atmosphere. The nuclear power plant has been shut down ever since.

“Nearly a decade ago, when Edison was designing these defective steam generators, it should have been obvious to them that this combination of radical changes required a license review,” said Gundersen on Wednesday. “If Edison had assessed the design changes correctly at that time, the flaws in the design and their consequences, including high void fraction and fluid elastic instability, would have been discovered.”

Edison, which wants to reboot the plant, installed the new steam generators at an expected cost to ratepayers of $670 million. The radically redesigned generators should have operated for decades, but they have rapidly deteriorated in less than two years as thousands of tubes were worn and damaged by rattling and clashing with each other and support structures.

“Edison played fast and loose by making radical design changes and ducking the rules,” Kendra Ulrich, nuclear campaigner with Friends of the Earth, said on Wednesday. “The result was the most rapid breakdown of such replacement steam generators in the history of the U.S. nuclear industry. If Edison had followed the rules, an NRC license review would have found these glaring defects, and the lives and livelihoods of millions of people would not have been put at risk nor would hundreds of millions of dollars have been squandered."