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Of dollars and dimensions 

Questions abound over Diablo seismic studies as PG&E argues you should pay more for them

Pacific Gas & Electric has lots of ’splaining to do these days.

The utility is smack-dab in the middle of a complex web of government agencies, committees, advocacy groups, legislators, and expert panels, each demanding that it perform studies to prove Diablo Canyon nuclear power plant is seismically safe before its customers cough up any dough for the plant’s relicensing.

Those studies are now the focus of some very tough questions: Will they be thorough? Are they worth $64 million? And, perhaps more theoretically, should it be customers or shareholders who pick up the tab?

PG&E wrapped the first phase of its studies—what it calls the “low-energy” 2-D phase—in mid-December. The company originally estimated the cost to ring in at roughly $17 million, which the California Public Utilities Commission (CPUC) authorized. But as a stipulation, the commission created Independent Peer Review Panel (IPRP), a group of appointees tasked with scrutinizing the science of PG&E’s studies. It includes reps from the state Energy, Coastal, and Seismic Safety commissions, and the state Geologic Survey.

Now, the utility says it’s out of money and is asking for another $47 million to cover the 3-D “high energy” phase, which, put quite simply, entails using massive air guns to blast loud sound waves into the sea.

There are a number of known faults relevant to Diablo Canyon, and two—the Hosgri and Shoreline faults—are thought by some U.S. Geological Survey scientists to intersect. While the Shoreline isn’t thought to be able to produce much of a temblor on its own, estimates for the Hosgri max out at a 7.3-magnitude earthquake. The possibility of both faults rupturing together has watchdogs barking for examination.

The plant is designed to withstand the ground motion from a 7.5-magnitude quake.

The studies are mandated by 2006’s Assembly Bill 1632, authored by State Sen. Sam Blakeslee (R-San Luis Obispo), which calls for modern technology to be used to assess the seismic risk associated with the geophysical landscape surrounding Diablo Canyon and San Onofre power plants.

The California Public Utilities Commission is ultimately responsible for evaluating to what extent those studies merit the increase. Hypothetically, after the commission approves the money and the studies are done and peer-reviewed, the utility could move back to federal relicensing.

But of course, the process isn’t as simple as that. Before PG&E can even begin the latest studies, it needs permits from the State Lands Commission, which is listening to concerns from the Independent Peer Review Panel.

And the panel has some serious concerns.

On Feb. 10, two witnesses with backgrounds in geophysics testified to the commission on behalf of the nonprofit ratepayer advocacy group, the Alliance for Nuclear Responsibility. The testimony came from Blakeslee and Dr. Doug Hamilton, who played a leading role in PG&E’s geosciences division for more than a quarter-century, dating back to 1971. Hamilton was on staff during the 1973 discovery of the Hosgri Fault, located a few miles from Diablo Canyon.

In his testimony, Hamilton, who has spent the last 14 years as a private consultant, said PG&E’s tests to date only partially comply with AB1632’s mandate.

“None of this data provided any information useful for significantly improving understanding of the seismic hazard to the [plant], and nothing in the planned additional surveys, both onshore and offshore, offers any prospect for any result beyond marginal improvement to what is already known,” Hamilton testified.

He also argued that other possible seismic hazards never even made it into PG&E’s studies, including uplifting of the Irish Hills, which he said encroaches upon the Shoreline Fault. He also said another smaller fault—the Diablo Cove Fault—is displacing bedrock at the foundation of a component in one of the reactors.

“This has the likely consequence of putting the safety of the plant, the electricity it provides to the state power grid, and potentially the health and property of the public at risk,” Hamilton said.

In a written response to his claims, PG&E didn’t contest the specifics of his testimony, but argued that most of it exceeded the scope of their studies and was “irrelevant” to the commission proceedings.

“Regardless of whether any of this information is true—and PG&E takes no position … on that—it is irrelevant to whether the Commission should authorize PG&E to recover an additional $47.5 million in customer rates for 2-D and 3-D seismic studies the [CPUC] already approved,” PG&E wrote.

 The utility also argued federal pre-emption, saying follow up on Hamilton’s claims would run afoul of the Nuclear Regulatory Commission.

CPUC Administrative Law Judge Barnett denied PG&E’s request to throw out Hamilton’s testimony.

At the urging of the county, Supervisor Bruce Gibson—who, like Blakeslee, holds a Ph.D. in geophysics—was added to the Independent Peer Review Panel in December. Gibson told New Times that the panel is questioning the methods being employed for the studies, what he compared to the difference between using an ultra-sound, an M.R.I., or a C.A.T.-Scan to look inside the human body.

The panel is also questioning whether the areas PG&E plans to conduct the 3-D studies are large enough to offer meaningful data on some important seismic features, such as the intersection of the Hosgri and Los Osos faults, as well as the southern butt of the Shoreline.

The panel recommended expanding some of the testing closer to shore. PG&E countered that waters off the coast are too shallow to conduct those types of high-energy tests.

“We want to make sure that the surveys will give us the best answer to where the critical geological targets are,” Gibson said. “And a big issue is: Are

they using the right design to get the best image?”

Getting to that answer has been a frustrating process, according to people involved. In his testimony, Blakeslee argued that PG&E’s “unwillingness” to share how its study plan was developed casts doubt on whether it will render useful data.

“Repeated requests and attempts have been made to work with PG&E on developing the study plan, by both myself and [IPRP],” Blakeslee said. “However, to date, PG&E has not provided the necessary information to assess whether the studies are adequately designed.”

Blakeslee also lashed out at what he called a “culture of complacency” among regulators and the industry, citing lax regulations that failed to prevent events such as Fukushima, the Deepwater Horizon spill in the Gulf, and, most recently, the September 2010 PG&E pipeline explosion that claimed the lives of eight people in San Bruno.

“The decisions made here at the Commission on Diablo Canyon—and at [San Onofre Power Plant] too, for that matter—could potentially be among the most consequential decisions ever made by the [CPUC],” he said.

PG&E issued no response to Blakeslee’s testimony, but spokesman Tom Cuddy said in a statement to New Times that there’s nothing more important than the safe operation of the facility: “While we are disappointed with last week’s ruling, we stand by our motion to strike their testimony and are looking forward to the next steps in the regulatory process.”

Hearings are set to recommence on April 18.

The licenses for Diablo Canyon’s two reactors aren’t set to expire until 2024 and 2025. Federal license renewal would extend their lives another 20 years.

Contact Staff Writer Matt Fountain at

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