Diablo Canyon Nuclear Plant on the Brink

Summary: The Diablo Canyon nuclear plant may be on the brink of closure after a top Nuclear Regulatory Commission executive, who has been lead inspector at the plant, called for a shutdown of the plant until its safety status can be determined. He did so in a report to the Commission that had been kept secret by the agency for more than a year until it was leaked and widely circulated last week, prompting calls for the plant to cease operations and planned hearings on the status of the plant by a Senate committee.

The old Diablo Canyon nuclear plant — too near to us all around here — may be on the brink of its operational end.

The biggest and longest-running fear is that the plant could be damaged or destroyed by an earthquake hitting a nearby ocean fault — one is only 650 yards away — and ripping through the plant. Seismic experts agree that could happen, unpredictably, any time. And few, if any, doubt the accompanying spread of radioactive airborne material over a broad area of San Luis Obispo County.

More likely right now, however, is the brink the PG&E-operated plant faces from a 42-page up-till-now secret report by a former Nuclear Regulatory Commission (NRC) lead inspector at the plant, Dr. Michael Peck, that calls for a shutdown of the plant until studies can determine the damage an earthquake shooting through one of those faults would have on the plant.

Peck's report was kept secret by the NRC for a year until apparently leaked and published last week by Friends of the Earth, a nonprofit environmental organization and nuclear monitor, which was reported by the Associated Press (AP) and subsequently other media.

Then, Friends of the Earth asked the NRC to shut down the nuclear plant to review whether it can withstand an earthquake nearby. The group also filed a petition with the NRC, asking for a hearing on seismic risks at the Diablo Canyon plant. The group accuses the plant of violating its federal operating license.

Then, a U.S. Senate committee called for public hearings on Peck's report.

But this is not primarily about some citizens group calling the NRC or PG&E, the plant owner, to task. That has happened innumerable times over the 30 years the plant has been operating. This is generated by a prominent insider, a top-level, highly experienced NRC staff member with the evidence needed to win. It's a "bombshell," Rinaldo Brutoco, Santa Barbara-based World Business Academy's president and Safe Energy Project leader, said.

Here is Peck's assessment in what is called a "differing professional opinion" (DPO) that was filed with the NRC a year ago (Diablo_Canyon_Seismic_DPO): "In 2011, Pacific Gas and Electric (PG&E) submitted a report to the NRC that included a reevaluation of the local geology surrounding the Diablo Canyon Power Plant. This report included deterministic evaluations concluding that three local earthquake faults are capable of generating significantly greater vibratory ground motion than was used to establish the facility safe shutdown earthquake (SSE) design basis. In response to this issue, NRC staff actions have been inconsistent with existing regulatory requirements and the facility design bases and Operating License. The staff failed to enforce plant technical specification requirements to shut down the Diablo Canyon reactors."

Continued reactor operation was dependent, he wrote, on PG&E's demonstration that technical specification required structure, system, or components (SSC) with "operability" following discovery of nonconforming and unanalyzed conditions associated with new seismic information. The failure to demonstrate "operability" required the licensee to take the prescribed technical specification actions for the "inoperable" equipment, including shutdown of the reactors. The "operability" determination method used by PG&E was inadequate because the methods used had not been approved by the NRC for use on the Diablo Canyon SSE design basis, he said.

The staff's conclusion in Research Information Letter 12-01 that "reasonable assurance of safety" exists does not provide an adequate basis for concluding "operability," Peck wrote. A "reasonable assurance of safety" does not satisfy the requirement that plant SSCs are capable of meeting the specific safety functions described in the SSE and double design earthquake (DDE) safety analysis, he said.

Peck stated that "PG&E submitted to the NRC, information concluding that three local earthquake faults are capable of producing greater ground motion than bounded by the NRC- approved safety analysis and the design basis. This condition rendered the plant seismic safety analysis nonconforming with NRC regulations. The NRC has failed to enforce quality requirements (Part 50, Appendix B) that required the licensee to take prompt action to correct the nonconforming safety analysis."

"We think it is a scandal that the NRC has taken no action on this report but has suppressed the DPO for more than a year," Brutoco said. "As Dr. Peck has recommended, we believe that the Diablo Canyon reactors should be shut down because their licenses are no longer valid and that the new seismic information suggests that they cannot withstand the kind of large earthquake possible in our area."

Mothers for Peace, which has a 41-year history of closely monitoring operation of the plant and as prominent legal intervenors, joined in assailing the handling of Peck's allegations by the NRC. "It is scandalous that the NRC, charged by Congress with protecting public safety, kept the Differing Professional Opinion (DPO) of its own expert employee a secret for over a year," Jane Swanson, spokesperson for the organization, said. "The agency should have responded to Dr. Peck's DPO and made it public."

"The burden of proof is not on Dr. Peck to prove Diablo unsafe," she continued, "but on the NRC and PG&E to show evidence that all components of Diablo could withstand the greatest possible ground motion that could be generated by simultaneous earthquakes on intersecting faults near Diablo. The fact that the NRC kept Dr. Peck's DPO under wraps until it was leaked to the Associated Press makes one wonder if the NRC is unable to refute his findings."

Beyond Nuclear urged the public to sign a petition on its website, calling for the Diablo Canyon plant to shut down.

Following the Associated Press report, the Senate Environment and Public Works Committee announced it would hold hearings into how the NRC has handled Peck's recommendation, which was filed in July, 2013 but kept secret until now. Sen. Barbara Boxer (D-California) is chair of the committee.

Lara Uselding, NRC public affairs officer, said Peck submitted non-concurrence papers (NCPs) in January, 2011, and January, 2012, followed by a Differing Professional Opinion (DPO) in July, 2013, detailing a disagreement with the NRC about how the new seismic information (Shoreline fault discovery) should be compared to the plant's current seismic license requirements.

Until the NRC completes its internal review process for the DPO, the agency is unable to comment on any potential documentation that is circulating as it is not final, she said. However, once the final review is complete the agency will have a final decision and the submitter (Peck) can request it be made public. DPOs can be very complex and take time to fully evaluate to support an informed decision. In this case, the agency rendered a decision and Peck appealed it so it is under additional review at this time, she said.

The NRC continues to conclude Diablo Canyon is built to safely withstand the effects of a Hosgri earthquake, she added, and that the plant would protect the public and the environment.

(Seismologists monitor activity on the Hosgri fault constantly because of its physical proximity to the Diablo Canyon plant. In fact, the fault lies only 2½ miles offshore from the nuclear power plant and runs over a long stretch of the Central Coast in San Luis Obispo County.)