Edison and contractor are blamed for flaws that shut down San Onofre
Federal regulators said Southern California Edison Co. and a contractor were responsible for design flaws that led to the permanent shutdown of San Onofre Nuclear Generating Station in June.
To the frustration of critics, the Nuclear Regulatory Commission on Monday proposed safety citations — but no fines — against Edison and its contractor, Mitsubishi Heavy Industries, for defective steam generators at the plant near San Clemente.
Edison said the proposed citation by the NRC came as no surprise. The utility described itself as an unhappy customer that bought a lemon, designed and built by Mitsubishi.
But critics questioned whether the NRC’s action was a slap on the wrist for closing Southern California’s largest single source of electricity and leaving ratepayers on the hook for a big chunk of the estimated $4.1-billion cost of decommissioning the 30-year-old plant.
“It’s proof that the NRC is a lap dog and not a watchdog,” said Damon Moglen, an energy specialist with the Friends of the Earth, a Washington environmental group.
Commission spokesman Victor Dricks rejected the criticism from Moglen and other anti-nuclear-power activists. “We’re taking appropriate action here in view of the low-to-moderate safety circumstances of the violation,” he said.
The leak was caught early, he said, and further radiation releases were prevented with the powering down of San Onofre Units 2 and 3 in January 2012.
The agency, Dricks added, is pursuing two other “administrative” inquires by its inspector general and its Office of Investigations.
But a commission critic, Dan Hirsch, who teaches nuclear policy at UC Santa Cruz, said he’s skeptical that either probe would come up with much.
“Mitsubishi screwed up the steam generator design, and Edison failed to catch it,” said Hirsch, president of the anti-nuclear group Committee to Bridge the Gap. “And, now, the NRC belatedly is issuing notices of violation to Edison for the failures.”
Edison, which operated San Onofre in a partnership with San Diego Gas & Electric Co. and the Riverside municipal power utility, announced in June that it would permanently close the plant and begin the decommissioning process.
The commission preliminarily determined that inadequate computer modeling by the contractor led to a deficient design of the steam generators and compromised safety.
As a result, increased water volumes caused vibrations that wore out tubes that carry water. Leaks released small amounts of radiation to the air.
Edison has 10 days to notify the commission whether it will accept the findings, while Mitsubishi has 30 days to respond in writing.
Edison has not determined how it might respond, spokeswoman Maureen Brown said. Mitsubishi said it is not contesting the report’s findings or the proposed citation.
Edison Vice President Pete Dietrich said Mitsubishi bears most of the fault for coming up with the flawed design and failing to properly verify that the system was adequately built.
“SCE is responsible for the safe operation of San Onofre and will continue to make safety our top priority as the plant is decommissioned,” he said. “Mitsubishi Heavy Industries is accountable for its failure to provide properly functioning steam generators.”
The flaw noted by the commission “had no impact” on the “unprecedented” vibration that caused the steam generator leak, Mitsubishi said in a statement.
In July, Edison announced that it was initiating legal action against Mitsubishi to recover damages from closure of a plant where it’s invested $2 billion.
When it was operating at full capacity, San Onofre made enough electricity to run more than 1.4 million homes in Southern California.
The NRC will hold its first public hearing on the San Onofre decommissioning at 6 p.m. Thursday at Omni La Costa Resort & Spa in Carlsbad.
Twitter: @MarcLifsher
