LOS ANGELES (Reuters) - Californians have long had an uneasy relationship with their two nuclear power plants, and the crisis in Japan raises new doubts about how long nuclear power will survive in the earthquake-prone state.
The first test of the Golden State's support for nuclear power is coming soon, as the nuclear plants perched on the scenic but fault-laden California coastline since the early 1980s begin the process for 20-year license renewals.
California banned construction of new nuclear power plants in the 1970s, when the then-governor Jerry Brown joined "no-nukes" activists in opposing construction of Diablo Canyon nuclear station on the Central Coast. Seismic safety worries played a prominent part in the campaign.
But the plant went ahead and nuclear power today generates about 15 percent of California electricity, slightly more than the portion generated by renewable sources in a state known for its clean-energy drive to combat global warming.
After the 9.0 quake and tsunami compromised reactors in Japan, lawmakers and activists have been quick to call for more seismic safety measures and monitoring for California's plants, considered the most vulnerable in the United States to major quakes. Brown, who is governor again, has so far been silent.
That pressure could make matters difficult, particularly for the owners of Diablo Canyon, Pacific Gas & Electric, who have to renew their licenses that expire in 2024 and 2025.
The licenses for California's other nuclear power plant, Edison International-owned San Onofre in between Los Angeles and San Diego, expire in 2022.
Renewing licenses for nuclear power plants begins years in advance of their expiration so that plans can be made to replace them if the application is denied. Diablo Canyon has already filed its renewal application, but San Onofre has not. Of the 104 operating U.S. reactors, the Nuclear Regulatory Commission has renewed 62 licenses and denied none.
That may not happen this time, however.
"The NRC has typically rubber-stamped these license renewal applications, but it's hard to see them turning a blind eye now," said Matt Freedman, an attorney with consumer group The Utility Reform Network in San Francisco. "The NRC will take a harder look and perhaps require additional measures, some of which will be expensive, to get those licenses."
The Obama administration has said it will press ahead with nuclear energy as an integral part of the U.S. "clean energy" mix. The Energy Department's budget includes $36 billion for loan guarantees to help build new nuclear reactors. The more than 100 reactors nationwide provide about 20 percent of U.S. energy.
Both PG&E and Southern California Edison say their nuclear power plants are built to withstand earthquakes far greater than the nearby faults are capable of producing.
A fault 5 miles away from San Onofre is capable of producing a quake up to a 7.0 magnitude, Edison spokesman Steve Conroy said, adding that the plant could withstand ground motions much greater than those produced by the 9.0-magnitude quake in Japan.
Diablo Canyon, meanwhile, could operate safely during up to a 7.5-magnitude earthquake, according to PG&E spokesman Kory Raftery. The four faults near the plant could potentially produce an earthquake of up to 6 to 6.5 magnitude, he said.
The NRC on Monday also sought to dispel fears about earthquake damage at U.S. nuclear power plants.
"We have a strong safety program in place to deal with seismic events that are likely to happen at any nuclear facility in this country," Chairman Gregory Jaczko said at a news conference at the White House, adding that the agency "will continue to take new information and see if there are changes that we need to make with our program."
Many in California, however, worry that the dangers could be far greater than operators or the NRC have planned for.
"There are many people who are very, very doubtful that they can trust whatever the company says about the plant," said Liz Apfelberg, a spokeswoman for San Luis Obispo Mothers for Peace, a group that has opposed Diablo Canyon since the early 1970s.
Fears about seismic dangers have also been stoked by the 2008 discovery of a fault line half a mile from Diablo Canyon.
California state Senator Sam Blakeslee, a Republican who represents the district in which Diablo Canyon is located, on Monday called for further seismic studies of the area.
"The devastating events in Japan underscore the importance of addressing the seismic uncertainty surrounding California's nuclear power plants," Blakeslee said in a statement. "Serious concerns about a newly discovered fault running underneath Diablo Canyon ... have so far gone unaddressed."
Shortly after the discovery of the new fault, the California Energy Commission recommended that PG&E conduct 3-D imaging. On Monday, PG&E's Raftery said the utility was still evaluating whether or not to perform the 3-D studies.
Reporting by Nichola Groom; Editing by Mary Milliken and Jackie Frank