Feinstein: San Onofre operators knew of generator defects during installation

Sen. Barbara Boxer and Rep. Edward Markey alleged Wednesday the operator of the shuttered San Onofre Nuclear Generating Station knew steam generators were flawed before they were installed at the plant.

The plant on the northern San Diego County coastline has been inoperative for more than a year since a small leak was discovered in a steam pressure tube in one of the two reactors. The other reactor was undergoing scheduled maintenance at the time — and neither has been restarted.

An investigation found that the leak was caused by vibrations that caused hundreds of steam pressure tubes to degrade faster than expected.

In a letter to Nuclear Regulatory Commission Chairwoman Allison Macfarlane, Boxer, D-Calif., and Markey, D-Mass., said they were concerned with information contained in a 2012 document from the manufacturer of the generators, Mitsubishi Heavy Industries.

Boxer and Markey said the document shows that Southern California Edison, the operator and majority owner of the plant, and Mitsubishi knew of “serious problems” with the design of the steam generators before they were installed in 2009 and 2010.

“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,” the senators wrote.

They called the new information “alarming.”

In a statement, SCE officials said the company has cooperated with the NRC and “has provided voluminous records, data, information and other accurate reports as requested.” The company said it respects the NRC process and is “committed to a transparent review” of its San Onofre operations.

Friends of the Earth, an anti-nuclear group opposing a restart at San Onofre, is demanding that SCE go through a rigorous amendment process to its NRC operating license prior to a restart because the new generators were of a much different design than their predecessors.

Kendra Ulrich, a Friends of the Earth campaigner, called the new report a “game changer” in their efforts to prevent a restart.

“This amounts to the willful endangerment of the lives and livelihoods of millions of people in Southern California,” Ulrich said. “Given the massive safety and corporate malfeasance implications, we are calling for the immediate release of this document in its entirety.”

The NRC is studying an SCE proposal to restart the reactor that had been undergoing maintenance, and is scheduled to render a decision in late April or early May. The agency has scheduled a public meeting for Tuesday in San Juan Capistrano.