SCE, Mitsubishi, Knew San Onofre Steam Generators Were Defective

A press release issued Wednesday by two prominent members of Congress charged that Southern California Edison (SCE) and Mitsubishi Heavy Industries (MHI) knew that the two replacement steam generators for the San Onofre nuclear plant were defective, and avoided adding safety measures to keep from triggering stricter scrutiny by the US Nuclear Regulatory Commission.

Senator Barbara Boxer of California and Congressman Ed Markey of Massachusetts send a letter to NRC Chair Allison Macfarlane on Wednesday stating, “Southern California Edison and MHI were aware of serious problems with the design of San Onofre nuclear power plant's replacement steam generators before they were installed.

Further, SCE and MHI rejected enhanced safety modifications and avoided triggering a more rigorous license amendment and safety review process.”

San Onofre units 2 and 3 have been shut down for over a year, because of serious problems in the replacement steam generators that caused serious damage and rendered operation of the two nuclear reactors unsafe.

Boxer and Markey reported today that this information came from a 2012 report by Misubishi Heavy Industries, which designed the replacement steam generators. They were supposed to operate for 20 years, and cost the plant owners $680 million.

Instead they lasted less than two years, and are costing the plants owners many more millions.

Despite all this SCE wants the restart Unit 2 this year, without having done any substantial repairs.

Wednesday’s press release gives an example from the 2012 MHI report to illustrate Boxer and Markey’s concerns, and why they are calling on the NRC to begin an investigation of SCE and MHI’s misbehaviors immediately:

“For example, the Report states that although SCE and MHI accepted some adjustments to the replacement steam generators, further safety modifications were found to have ‘unacceptable consequences’ and were rejected: ‘Among the difficulties associated with the potential changes was the possibility that making them could impede the ability to justify the RSG [replacement steam generator] design’ without the requirement for a license amendment. The Report also indicates that SCE's and MHI's decision to reject additional safety modifications contributed to the faulty steam generators and the shutdown of reactor Units 2 and 3.”

As popular opposition to the restart of San Onofre mounts, Boxer and Markey’s final words echo those of the people:


“This newly-obtained information concerns us greatly, and we urge the NRC to immediately conduct a thorough investigation into whether SCE and MHI did in fact fail to make needed safety enhancements to avoid the license amendment process.

"All people in our nation, including the 8.7 million people who live within 50 miles of the San Onofre plant, must have confidence in the NRC's commitment to put safety before any other concern.

"We believe this alarming Report raises serious concerns about SCE's and MHI's past actions. Safety, not regulatory short cuts, must be the driving factor in the design of nuclear facilities, as well as NRC's determination on whether Units 2 and 3 can be restarted.”