Posted on December 16, 2013

VIDEO: Seismic Safety at Diablo Canyon Power Plant Makes PG&E an Industry Leader


By Tracy Correa

SAN LUIS OBISPO COUNTYDiablo Canyon Power Plant plays a major role in helping PG&E generate and deliver to its customers some of the nation’s cleanest electricity.

And there’s nothing more important to PG&E and its customers in the San Luis Obispo County region than its safe operation.

Diablo Canyon was built to a higher standard than commercial buildings to ensure that key safety systems continue to operate during an earthquake, said Jearl Strickland, PG&E's director of nuclear projects. (Photos by James Green.)

That’s why PG&E constantly works to ensure the plant can withstand a major seismic event – an ongoing process that puts it on the cutting-edge of seismic research and solidifies Diablo Canyon Power Plant as an industry leader.

“Seismic safety for Diablo Canyon wasn’t simply a one-shot deal with the original design and construction of the power plant. Through our long-term seismic program we’ve continued to learn additional knowledge on how earthquakes behave around the world and we continue to apply those lessons learned,” said Jearl Strickland, PG&E’s director of nuclear projects.

PG&E constantly collects new data – this includes recently-conducted two- and three-dimensional surveys to better understand earthquake faults. The most recent tests are being analyzed to help PG&E update its seismic plan.

Strickland recently gave Currents a tour of Diablo Canyon, pointing out areas to help it withstand the effects of an earthquake.

Unlike regular commercial buildings – built to hold up for occupants to safely escape during an earthquake – Diablo’s structures adhere to a higher standard so that the plant remains intact, and key safety systems continue to operate.

Nuclear plant safety became even more critical after the Fukushima Daiichi power plant incident in 2011. But there are some major differences between Diablo Canyon and the Japanese plant. Namely, Diablo’s reactors and safety systems stand 85-feet above sea level – well above predicted tsunami levels — while Daiichi was just 20 feet above. That’s critical because it wasn’t the earthquake, but the subsequent tsunami, that crippled the Japanese plant. And, Diablo has far more back-up systems.

Norm Abrahamson is a PG&E seismologist and an industry expert who serves as an adjunct professor at the University of California.

Diablo’s licensing required the establishment of a long-term seismic safety program with seismic experts, such as Norm Abrahamson, who constantly evaluate the plant’s safety, taking into account lessons learned from earthquakes worldwide. Their work results in living-document plans that don’t just sit on a shelf, but are incorporated at Diablo Canyon.

“Part of our job here is to keep up with any seismic studies or advances around the world that might be applicable to Diablo Canyon,” said Abrahamson, a seismologist who has a PhD in geophysics and is an adjunct professor at UC Berkeley and UC Davis. He specializes in seismic hazard analysis and has been with PG&E nearly two decades.

PG&E’s experts are often called on to share new research information – with government agencies, as well as the nuclear industry.

San Luis Obispo County also benefits. PG&E’s research is shared with local government agencies and enhances the county’s overall emergency readiness plans.

“Both as a resident of San Luis Obispo County and the San Luis Obispo County emergency services manager, I’m very confident in our safety related to the nuclear power plant, said Ron Alsop, emergency services manager for San Luis Obispo County.

Diablo Canyon's long-term seismic safety plan is a living document that is used as part of the plant's operations.

Strickland said PG&E is committed to the safety of the community and the nearly 1,500 plant employees.

“Considering how robust the structures and facilities are constructed here at Diablo Canyon… In the event of a major earthquake, this is the place that I would want to be.”

For more information on PG&E’s seismic research program, please visit

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