Skip to main content

ALERT: KPBS Radio is undergoing scheduled upgrade work which may result in temporary signal outages.

LATEST UPDATES: Tracking COVID-19 | Vaccines | Racial Justice

Feds Release Confidential Report On San Onofre Nuclear Plant

The long-awaited Mitsubishi Heavy Industries Report was made public today and it confirms what two lawmakers announced last month.

The report shows Southern California Edison was aware of design flaws with its replacement steam generators years before they were installed at San Onofre nuclear plant. It says Southern California Edison and Mitsubishi's joint team of experts knew the steam generators could produce what's called void fraction that would lead to thinning of the tubes inside the steam generators.

It also indicates Edison considered making changes. But it shows Edison believed the changes carried unacceptable consequences, including a licensing amendment process with federal regulators. Edison installed the new generators in 2010 and 2011 without the fixes.

A thinning tube ruptured last year at San Onofre causing a radiation leak. The plant has been closed ever since.

Damon Moglen of the environmental group Friends of the Earth called the report a bombshell.

"It proves conclusively that Edison was aware of these really troubling problems all the way back in 2005 and rather than doing what they needed to to guarantee safety, they went ahead and disregarded changes," Moglen said.

Edison did not immediately respond to a request for comment. But in the past, Edison has said it would never, and did not, install steam generators that it believed would not perform safely.

The company wants to restart the plant at reduced capacity. After the report was made public, California Senator Barbara Boxer said the Nuclear Regulatory Commission should investigate whether Edison fully complied with its legal obligations at San Onofre.

"A full investigation is critical to any determination on whether it is safe to restart San Onofre Units 2 and 3,” Boxer said.

The NRC would only say its probe is ongoing.


San Diego News Now podcast branding

San Diego news; when you want it, where you want it. Get local stories on politics, education, health, environment, the border and more. New episodes are ready weekday mornings. Hosted by Anica Colbert and produced by KPBS, San Diego and the Imperial County's NPR and PBS station.

  • Need help keeping up with the news that matters most? Get the day's top news — ranging from local to international — straight to your inbox each weekday morning.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Photo of Amita Sharma

Amita Sharma
Investigative Reporter

opening quote marksclosing quote marksAs an investigative reporter for KPBS, I've helped expose political scandals and dug into intractable issues like sex trafficking. I've raised tough questions about how government treats foster kids. I've spotlighted the problem of pollution in poor neighborhoods. And I've chronicled corporate mistakes and how the public sometimes ends up paying for them.

Want more KPBS news?
Find us on Twitter and Facebook, or sign up for our newsletters.

To view PDF documents, Download Acrobat Reader.