2014-08-27 by David R. Baker for "San Francisco Chronicle" daily newspaper [http://www.sfgate.com/business/article/Petition-seeks-closure-of-Diablo-Canyon-nuclear-5714455.php]:
Diablo Canyon's reactors need to be able to shut down safely in the wake of an earthquake, the plant's license says. (Photo: Michael Mariant, Associated Press)
The environmental group that helped shut down the San Onofre nuclear plant last year is now using the same tactic in a bid to close California's last nuclear power plant, PG&E's Diablo Canyon.
The plant, near San Luis Obispo, risks catastrophic failure during an earthquake and should be shuttered pending a public review of its safety, according to a petition that Friends of the Earth filed with federal regulators Tuesday.
The group filed the petition with the Nuclear Regulatory Commission, arguing that Diablo's design may not be strong enough to withstand earthquakes from fault lines that nearly surround the plant. As proof, the environmentalists cite a recently disclosed report from a former federal inspector at the plant who reached the same conclusion.
Earthquake fears have long shadowed the plant, which opened in 1985 after years of protests. Several fault lines were found only after work on the plant began, with the latest discovery coming in 2008.
Diablo's operating license requires that it be able to shut down safely following a major quake. But the petition argues that nearby faults are capable of much stronger shaking than Diablo's design anticipated, rendering the license invalid.
"PG&E cannot run this reactor without a valid license, and they don't have one," said Damon Moglen, senior strategic adviser for Friends of the Earth. "There is nobody in this country, PG&E included, who would want to build a reactor today at Diablo Canyon. It would never pass muster."
It mirrors the strategy the environmental group used to help force the closure of the San Onofre nuclear plant in San Diego County.
San Onofre's operator, Southern California Edison, shut down the plant in 2012 after a small leak of radioactive steam revealed equipment wearing out faster than anticipated. Friends of the Earth filed a petition insisting that Edison apply for a license amendment - a process that requires public hearings - before restarting the plant. The NRC's licensing board agreed. Three weeks later, Edison announced that it would decommission the plant instead.
Friends of Earth now wants PG&E to seek a license amendment to continue running Diablo.
"They now know that the ground motion of these faults is greater than is contained in their license," Moglen said. "I think the argument here is extremely straightforward."
The move follows the disclosure of a 2013 document written by a former NRC inspector stationed at the plant. The inspector, Michael Peck, recommended shutting down Diablo until the commission determined whether the plant's equipment could survive higher seismic stress levels.
"Continued reactor operation outside the bounds of the NRC approved safety analyses challenges the presumption of nuclear safety," Peck wrote.
Peck's opinion was revealed by the Associated Press on Monday, touching off a fresh round of criticism of the plant. Sen. Barbara Boxer, who chairs the Senate Environment and Public Works Committee, promised a public hearing into the matter.
"A year ago, a qualified NRC inspector informed the NRC that the Diablo Canyon nuclear power plant should be shut down until it is clear that the plant can withstand the kind of earthquake that has been predicted for the area," said Boxer, D-Calif. "I am alarmed that the NRC has not followed this recommendation and has not required actions to protect the 500,000 people who live near the site."
PG&E insists that the plant can withstand earthquakes on any of the faults nearby. Following the 2011 meltdown at the Fukushima Dai-ichi nuclear plant in Japan, PG&E conducted more seismic tests near the plant, including embedding seismometers on the ocean floor. The company is now analyzing that data, said spokesman Blair Jones.
"The region surrounding Diablo Canyon is one of the most seismically researched places in the United States," Jones said.
The operating licenses for Diablo's twin reactors expire in 2024 and 2025, and until Fukushima, PG&E had been in the process of asking the NRC to renew the licenses. That process is now on hold until PG&E finishes its latest seismic study and submits the results to California regulators.
"Any decision on whether or how to proceed with license renewal will wait until after we complete the seismic report," Jones said.
"Diablo Canyon nuclear plant 'near miss' in report"
2011-03-18 by David R. Baker for the "San Francisco Chronicle" daily newspaper [http://www.sfgate.com/business/article/Diablo-Canyon-nuclear-plant-near-miss-in-report-2389034.php]:
PG&E's Diablo Canyon nuclear power plant in Avila Beach, Calif. on Friday, May 26, 2006. The two spent fuel storage pools are nearing its capacity of 2,648 cells so plant officials are constructing a dry cask storage area to hold future radioactive fuel cell waste.
(The Chronicle Photo: Paul Chinn, The Chronicle)
For 18 months, operators at the Diablo Canyon nuclear plant near San Luis Obispo didn't realize that a system to pump water into one of their reactors during an emergency wasn't working.
It had been accidentally disabled by the plant's own engineers, according to a report issued Thursday on the safety of nuclear reactors in the United States.
The report, from the Union of Concerned Scientists watchdog group, lists 14 recent "near misses" - instances in which serious problems at a plant required federal regulators to respond.
The report criticizes both plant operators and the Nuclear Regulatory Commission for allowing some known safety issues to fester.
"The severe accidents at Three Mile Island in 1979 and Chernobyl in 1986 occurred when a handful of known problems - aggravated by a few worker miscues - transformed fairly routine events into catastrophes," the report notes.
The problem -
The problem at Diablo Canyon, which is owned by Pacific Gas and Electric Co., involved a series of valves that allow water to pour into one of the plant's two reactors during emergencies, keeping the reactor from overheating.
The loss of water in a reactor can lead to at least a partial meltdown - a process believed to be under way at Japan's stricken Fukushima Dai-ichi nuclear plant after last week's earthquake and tsunami.
Engineers at Diablo Canyon inadvertently created the problem while trying to solve another issue, according to the report.
A pair of remotely operated valves in the emergency cooling system was taking too long to move from completely closed to completely open. So engineers shortened the distance between those two positions, according to the report.
Unfortunately, two other pairs of valves were interlocked with the first. They couldn't open at all until the first pair opened all the way. No one noticed until the valves refused to open during a test in October 2009, 18 months after the engineers made the changes.
"It was disabled, and they didn't know it," said Jane Swanson, spokeswoman for the Mothers for Peace anti-nuclear group, which frequently spars with federal regulators over Diablo Canyon. "That's unforgivable, and it's not that unusual."
In an emergency, Diablo Canyon operators still could have opened the valves manually.
They could also have used a separate system of pumps to inject water into the reactor, PG&E spokesman Kory Raftery said.
"We want to make sure we put safety first - that's why we have redundant systems," he said.
He added, "The potential is very small for the type of situation where we'd need this system in the first place."
PG&E has asked the Nuclear Regulatory Commission to extend the licenses of Diablo Canyon's twin reactors past their original expiration dates of 2024 and 2025. Mothers for Peace has opposed that move.
The valve problem and the union's report, Swanson said, illustrate how even minor technical issues at a plant have the potential to cause serious problems.
'Domino effect' -
"Any given nuclear power plant is such a complex system," she said. "As we've seen in Japan, the domino effect can happen."
With the Japanese crisis riveting world attention, Sens. Barbara Boxer and Dianne Feinstein called on the Nuclear Regulatory Commission on Wednesday to perform thorough safety inspections at Diablo Canyon as well as California's other commercial nuclear plant, San Onofre, in San Diego County.
But the commission's chairman said Thursday there was no immediate need to inspect any U.S. nuclear plants.
Later Thursday, President Obama said the United States faces no danger of radioactive contamination from Japan's nuclear plant and has ordered a comprehensive review of safety at U.S. plants.
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