New Seismic Research Confirms Diablo Canyon Safety

By Ed Halpin

The nation's nuclear power plant operators know they have a special obligation to protect public safety. To the 1,500 men and women of PG&E who live and work in the San Luis Obispo and northern Santa Barbara Counties region in support of the Diablo Canyon Nuclear Power Plant, there is no higher priority than operating our plant with a maximum emphasis on safety.

A key focus in this objective is to ensure Diablo Canyon remains prepared to withstand the highest level of seismic activity from nearby earthquake faults.

The potential of seismic activity throughout California, and particularly in the region surrounding Diablo Canyon, is well documented and studied. PG&E has regularly performed and funded research to assure ourselves and the public of the plant’s continued ability to operate safely in the event of a major seismic event.

We've recently submitted to the Nuclear Regulatory Commission the most comprehensive seismic study of the area surrounding the plant since it began operation in the mid 1980’s. These findings reaffirm that it is constructed to withstand and able to perform key safety functions during and after the largest potential earthquakes that could occur in our region.

This conclusion by scientists follows more than a year of analyzing new research using state-of-the-art mapping technologies to look into the Earth. This effort has provided a wealth of new data and has also fulfilled a key commitment PG&E made to this community and our customers regarding ensuring seismic safety at Diablo Canyon after the major 2011 earthquake in Japan.

The findings are important not only to us at PG&E and to our plant’s neighbors, but to all our customers who greatly value Diablo Canyon’s ability to deliver clean, reliable energy that’s free of greenhouse gases.

In addition to recently announcing the findings to community members and officials, PG&E has also provided the research to the California Public Utilities Commission’s Independent Peer Review Panel, an advisory task force that reviewed how the seismic studies would be performed and provided insight and comments to researchers. The same panel now has the opportunity to review the findings.

While this new information confirms previous safety analyses of Diablo Canyon, neighboring communities should know that our work to assess seismic safety at Diablo Canyon doesn’t stop here. This research will be incorporated into a seismic re-evaluation for the plant that is due next year to the NRC. All commercial nuclear power plants in the country are performing such updates at the direction of this oversight agency.

The research will also support our Long Term Seismic Program, which continually assesses seismic safety at Diablo Canyon. This is a unique program in the U.S. commercial nuclear power plant industry and is required by PG&E’s licenses to operate the facility. It consists of a geosciences team of professionals who regularly partner with independent seismic experts to study the seismicity of our region and earthquakes around the world to ensure that Diablo Canyon remains safe.

Beyond Diablo Canyon’s safety, we believe the results of the study can benefit the safety of other critical infrastructure on the Central Coast as well. PG&E has shared the new research with local and state agencies, which can use it to evaluate the safety of the region’s roads, bridges, dams and other infrastructure. This information will also be of use to agencies charged with creating and implementing local emergency preparedness plans.

We invite those who would like to learn more about the seismic studies and safety at Diablo Canyon to attend an open house on October 2, 2014 at PG&E’s Energy Education Center in San Luis Obispo. Community members will be able to interact with the research team and see presentations about the results. In addition, those who want to see how PG&E fulfills our commitment to safety every day are invited to take a public tour of Diablo Canyon. Information on tours can be found at

Ed Halpin is PG&E’s Senior Vice President and Chief Nuclear Officer.

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