Friends of the Earth asked Arine Gundersen to make a formal report on the damaged steam generators at San Onofre. Gundersen is an energy advisor with 40‐years of nuclear power engineering experience. A former nuclear industry senior vice president, he earned his Bachelor and Master Degrees in nuclear engineering, holds a nuclear safety patent, and was a licensed reactor operator. During his nuclear industry career, Gundersen managed and coordinated projects at 70‐nuclear power plants around the country. The document his firm produced is substantial in terms of technology and processes that have gone wrong.
“If the NRC allows either San Onofre reactor to restart without a thorough root cause analysis and another tube or tubes were to fail, radioactive releases might be significantly large The reactors both have severe problems and Edison made changes that the NRC appears not to have understood or were not told about. Fairewinds Associates recommends that both [San Onofre] Unit 2 and Unit 3 remain shut down until the root cause of each nuclear reactor rapid steam generator tube failures are understood and repaired, reliability is assured, and radioactive releases are prevented,” Gundersen concludes in the report.
The paper also documents that Edison misled the federal Nuclear Regulatory Commission about changes made to the plant, which have led to unforeseen and undiagnosed safety problems.
Fairewind Associates identified four changes that could account for the rapid deterioration:
the tube alloy was changed;
reactor flow rate was changed;
more steam generator tubes were added; and/or
modifications were made to the “egg crate” that holds the tubes separate and apart.