Diablo Canyon nuclear power plant near San Luis Obispo, Courtesy Creative Commons

Geologists have long said California is long overdue for the “big one”—a large earthquake or storm that could test the safety capabilities of California’s structures.

And in light of several recent man-made and natural disasters, California lawmakers are urging nuclear regulators to reassess the potential dangers that may lurk around California’s two nuclear power plants and their ability to withstand earthquakes.

The one-year anniversary of the accidental, yet man-made, BP oil spill disaster—that killed 11 workers aboard the Deepwater Horizon oil rig and sent 4.1 million barrels of oil gushing uncontrollably into the Gulf of Mexico for 87 days—provides a context to reevaluate the safety of California’s own energy-source facilities.

Several other examples in recent history beg for attention to safety and precautionary measures.

PG&E is currently under investigation to determine the cause of last September’s San Bruno pipeline explosion, which killed eight people.

And now, another one of PG&E’s operations faces controversy regarding safety.

California’s two nuclear power plants, San Onofre (operated by Southern California Edison) and Diablo Canyon (PG&E operated), are both built near geological fault lines.

With a new alert of possible danger and the catastrophic results of both man-made and natural recent disasters, California lawmakers are urging the U.S. Nuclear Regulatory Commission to delay PG&E’s request to relicense the Diablo Canyon plant until the NRC performs 3-D seismic studies of the area.

In 2009, the U.S. Geological Survey discovered a new fault line—the Shoreline Fault—less than one mile from the Diablo Canyon nuclear power plant near San Luis Obispo; however, the new fault line was not widely known until last month.

Additionally, Diablo Canyon sits about three miles away from the widely known Hosgri fault line.

California lawmakers are concerned that the NRC has not done enough to assess the possible dangers of the newly discovered fault line before relicensing the plant.

“I am very concerned that the NRC is looking at this issue with rose-colored glasses,” said state Sen. Sam Blakeslee (R-San Luis Obispo) at a state energy hearing last Thursday.

At the hearing, called “After Japan: Nuclear Power Plant Safety in California,” Blakeslee asked an NRC representative whether the NRC was concerned about the existence of a fault line that has not been independently reviewed to assess for safety.

“We have evaluated all data presented to us, and we believe Diablo Canyon is safely operating today,” said the NRC’s deputy director, Troy Pruett.

Because of last month’s tsunami and magnitude-9.0 earthquake that damaged Japan’s Fukushima power plant (which was made to withstand a 7.9-magnitude quake), the state commission met to discuss California’s energy safety.

Blakeslee, referencing last month’s devastation in Japan, told Pruett, that the Tokyo Electric Power Company “made similar assurances about their understanding of offshore fault systems,” and now California has information about a new fault line.

The NRC’s Pruett said more than once that the NRC believes Diablo Canyon is safe.

“If there’s a seismic safety concern that threatens the safe operation of that facility, it gets dealt with outside of the license renewal process,” Pruett said. “If it’s an immediate safety concern, it gets dealt with on an immediate basis.”

This June, the NRC will release their safety and environmental report to the public. Pruett said that in June, the NRC will continue to assess any new safety concerns.

“We continually review and assess data as it’s made available to the commission,” Pruett said.

But Blakeslee, visibly frustrated, asked how the NRC planned to relicense Diablo Canyon when information about the newly discovered fault line was not yet available.

“We’re now in a situation where we have information about a Shoreline fault…in my district, next to my constituents, and you’re telling me you’re just going to continue business as usual and not delay to get the information before you do your safety review, and that’s not acceptable.

The Wall Street Journal reported a PG&E spokesperson saying the Diablo Canyon plant was designed to withstand a magnitude-7.5 earthquake.

Pruett said the NRC has not yet made a decision on whether to delay PG&E’s relicensing application.

“Nuclear power plants are among the safest, most secure industrial operations in the world. At Diablo Canyon, safety remains every employee’s top priority,” PG&E’s website says.

Next week will also mark the 25th anniversary of the Chernobyl nuclear accident in Ukraine, which is considered the worst nuclear accident in history.

Reach reporter Raquel Estupinan here.