The Nuclear Regulatory Commission (NRC) would like to ensure readers of The Malibu Times have as full a picture as possible regarding safety at the Diablo Canyon nuclear power plant.
The bottom line is that the NRC concludes the plant is operating safely and can continue doing so. The agency’s independent reviews of information about faults near Diablo Canyon consistently find the plant can safely withstand large earthquakes possible in that area.
The most recent information about Diablo Canyon comes from an NRC directive in the wake of the March 2011 Fukushima accident. The agency asked every U.S. nuclear power plant to use up-to-date information and modern analyses to re-evaluate their potential earthquake hazard. Diablo Canyon was one of three Western U.S. plants that submitted its re-evaluations in March. The NRC’s review of PG&E’s information concludes the plant can safely operate while additional analysis checks for possible safety enhancements.
The most recent work builds on PG&E’s comprehensive seismic evaluation program, put in place in the mid-1980s before Diablo Canyon started operating. This program identifies and evaluates potential new seismic hazards, and the NRC reviews those evaluations to ensure agency requirements are met.
Recent examples of this work include PG&E’s examination of the “Shoreline fault” near Diablo Canyon, as well as a state-mandated review of several faults, including Shoreline. An NRC inspector at the plant offered a “differing professional opinion” regarding the Shoreline fault and the plant’s seismic safety. After an extensive, multi-layered review of the inspector’s opinion the NRC’s Executive Director for Operations determined Diablo Canyon remains within its approved design and licensing basis, and there are no current concerns for safe operation. At the request of the staff member, the NRC made the entire opinion and review available on the NRC’s website at pbadupws.nrc.gov/docs/ml1425/ML14252A743.pdf.
The NRC recognizes that the history of seismic safety at Diablo Canyon is a long and complicated one. We have and will continue to review and inspect changes and potential risks to the station in an open and transparent manner to ensure the safety of the citizens of California, and the entire nation.
Scott Burnell
NRC Office of Public Affairs, Headquarters