Former senior resident inspector at Diablo Canyon nuclear power plant Michael Peck has submitted a lengthy opinion piece to The Tribune explaining his reasons for appealing the Nuclear Regulatory Commission’s conclusion that Diablo Canyon is seismically safe.
In his 3,000-word opinion piece sent Tuesday, Peck said he was “left with the impression that the NRC may have applied a special standard for Diablo Canyon.”
He said that in his 30-year career in the NRC, he had never seen the agency handle a safety evaluation the way it had with Diablo Canyon.
In his appeal, called a differing professional opinion, Peck disagreed with the analysis the NRC used in reaching its conclusion that the plant is seismically safe. Peck recommended that more analysis is needed to determine whether the plant could be safely shut down in the event of an earthquake along the recently discovered Shoreline fault.
The plant’s design and licensing were based on withstanding a 7.5-magnitude earthquake using a "double-design earthquake" safety analysis. Diablo Canyon owner PG&E wanted to change its operating license so that its safety would be based on its continued ability to withstand a 7.5-magnitude quake on the Hosgri fault.
The NRC and PG&E maintain that ground motions the Shoreline fault could produce would not exceed the Hosgri levels. Seismic studies recently completed by PG&E reaffirmed this conclusion.
“We continue to respect Dr. Peck’s right to voice his concerns,” said Tom Cuddy, PG&E spokesman. “This is obviously a very complex issue. We will continue to be completely transparent in our analysis of the seismic safety of the plant.”
Peck argued that to use the Hosgri fault to evaluate the safety of the plant rather than the closer Shoreline fault would have required a license amendment and that, normally, the plant would have to be shut down while the amendment was completed.
“The fix was to make the Hosgri the safe shutdown earthquake,” he said. “That takes a license amendment. That’s not an opinion; it’s just a fact.”
The NRC does allow a plant to continue operating while applying for an amended permit, Peck said, if the owner can show that key safety equipment would continue to operate in a quake during the application process. He concluded that it was “all but impossible” for PG&E to be able to show that.
He was surprised when the NRC said “insufficient information was available to complete an operability evaluation” but continued to let the plant operate anyway.
Peck initially brought his concerns about seismic safety issues to the NRC in 2011. In 2013, he elevated his concerns to the highest official level by filing a differing professional opinion. The agency took more than a year to formally respond to his allegations.
The NRC convened an independent review panel to examine Peck’s allegations and determined that the plant continues to operate safely. The NRC concluded that adequate seismic margins existed and the plant was safe to operate using the Hosgri fault as the safety standard.
“I have exhausted the NRC process for raising nuclear safety concerns,” Peck said in his piece. “At every turn the agency reinforced that their original conclusions and actions had been correct.”
Peck said he does not know why the agency decided to apply methodologies to Diablo Canyon that are different than those he had seen used during his 30-year career with the NRC.
“I was not involved with those discussions,” he said.
He went on to say that it is not clear whether the NRC’s decision puts the public at risk from an earthquake near the plant.
“You can’t say the public is at risk, but you also cannot say that there is no risk,” he said. “It is somewhere in between in the spectrum and depends on how big the earthquake is.”
The opinion piece raises the same issues that Peck enumerated in his formal appeal to the NRC in 2013. Peck told The Tribune he was motivated to submit the piece to set the record straight because he was, in part, disappointed with how the media had covered the issue.
He objected to being described by the national media as a whistleblower, he said. The term is incorrect because he followed the NRC’s standard internal appeals procedures, he said. He did not leak an advance copy of his appeal to the public.
“I’m just trying to provide some background,” he said of his motivation for writing the opinion piece. “Before I walk away from this, I want people to understand what this is all about.”
Peck was assigned to the plant from 2008 to 2012 before applying and being accepted to the agency’s technical training center in Chattanooga, Tenn, where he is now a senior reactor technical instructor. He declined to discuss how his public disagreements with NRC senior staff may have affected his career with the agency.
Peck’s entire opinion piece can be found online here.