A Nuclear Regulatory Commission board Thursday heard nearly six hours of arguments on whether Diablo Canyon nuclear power plant’s two operating licenses should be renewed another 20 years in light of the discovery of new earthquake dangers.
An Atomic Safety and Licensing Board at NRC headquarters in Rockville, Md., heard oral arguments on five legal challenges in opposition to extending Diablo Canyon’s licenses to 2044 and 2045.
The NRC is writing an environmental impact statement to cover Diablo Canyon’s license renewal. The agency will hold two meetings in San Luis Obispo on Aug. 5 to take public comment on the issues the report should address.
A decision on whether to renew the licenses isn’t expected until 2017. The NRC could rule on the five legal challenges within the next few months, however.
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Four of Thursday’s legal challenges were filed by the antinuclear group San Luis Obispo Mothers for Peace. The group alleges that Pacific Gas & Electric Co. has understated the earthquake threat facing Diablo Canyon and is ignoring a wide range of renewable energy options available to replace the power generated at Diablo Canyon.
Mothers for Peace attorney Diane Curran said the discovery of the Shoreline Fault just offshore from Diablo Canyon in 2008 greatly increased the seismic risk to the nuclear power plant.
The 2011 Fukushima Daiichi nuclear disaster in Japan showed that earthquakes can be much bigger and cause more damage than anticipated, she said.
“This is a dangerous site for a nuclear power plant, there’s no doubt about it,” she said. “Even a small or moderate earthquake could cause tremendous damage if it happens near or underneath the plant.”
Attorneys for PG&E argued that all of the legal challenges are baseless because recent seismic analysis has shown that the plant could safely shut down in the event of a quake along the Shoreline Fault.
PG&E maintains a full-time staff of seismologists and Diablo Canyon is the most seismically studied nuclear power plant in the nation, they said.
They also argued that renewable power is too intermittent and unreliable to replace Diablo Canyon and they have environmental impacts of their own, including a much more intensive use of land. For example, two large, commercial scale solar plants in eastern San Luis Obispo County cover nine square miles but produce only 10 percent of Diablo Canyon’s 2,300 megawatts of power.
“Mothers for Peace has never put forth evidence that alternative energy would have lesser environmental impacts than nuclear,” said Tyson Smith, a PG&E attorney.
The board also heard arguments about a legal challenge filed by the environmental group Friends of the Earth. That group contends the NRC should have required a license amendment for Diablo Canyon once the Shoreline Fault was discovered.
“The staff has approved major expansions to the operating licenses,” said Richard Ayres, Friends of the Earth attorney. “These changes should be given a hearing so the public can give input.”
The NRC and PG&E disputed this. They argued that the decision that Diablo Canyon was safe to continue to operate was a standard oversight action by the NRC that did not require a license amendment.
“Diablo Canyon’s license and licensing basis remain unaltered,” said David Repka, PG&E attorney. “Increased risk is not a change to the license.”
Judge Paul Ryerson, the board’s chairman, said decisions on the Mothers for Peace challenges should be handed down by Aug. 24 and a ruling on the Friends of the Earth contention is due by Oct. 8. Further hearings could be held if the panel accepts any of the challenges.
Atomic Safety and Licensing Boards are independent three-person bodies within the NRC that conduct adjudicatory hearings and makes decisions on legal challenges to licensing actions.