http://www.sanluisobispo.com/news/local/story/104513.html

By David Sneed

PG&E scientists are talking with officials in Japan about the recent earthquake there, which damaged a large nuclear facility with seismic surroundings that bear a striking resemblance to those of San Luis Obispo County’s plant.

The Kashiwazaki-Kariwa plant in Japan—the world’s largest, with seven reactors — released radioactive water into the ocean and experienced fires and other radioactive leaks in the wake of the magnitude-6.8 quake that hit July 16.

Japan is a seismically active country, and the damaged plant was built near several fault lines. Japanese officials had been under the assumption that the nearby fault that shifted last week is a strike-slip fault, in which the two sides of the fault move horizontally against each other.

But it turned out to be a strike-thrust, in which the two sides hit vertically and produce a much stronger jolt.

In San Luis Obispo County, the Hosgri fault lies three miles offshore of the Diablo Canyon nuclear power plant—on the coast just north of Avila Beach.

Hosgri is also thought to be a strike-slip fault. But PG&E seismologists recognize that it also could be a strike-thrust.

It’s standard procedure for PG&E scientists to investigate all major earthquakes for lessons that might apply to Diablo Canyon, said plant spokesman Pete Resler.

PG&E seismologists have not had any face-to-face meetings with Japanese officials but have been monitoring the situation. They haven’t issued any formal findings.

Diablo is designed to withstand a quake as powerful as the one in Japan, Resler said.

“We do have adequate seismic margins for all types of quakes,” he said.

Quakes are one of the main safety concerns in regard to nuclear power. In 1976, PG&E shut down its nuclear plant at Humboldt Bay because of multiple seismic concerns.

The Japanese quake has rekindled concerns about nuclear plants and earthquakes, said Rochelle Becker, executive director of the Alliance for Nuclear Responsibility.

The quake shook the ground 21/2 times stronger than plant designers had anticipated, according to post-quake reports.

In addition, scientists studying the area in the wake of last week’s quake may have uncovered an additional fault line — one that may run directly under the land on which the Japanese power plant sits.

In light of the recent quake and the Japanese fault’s similarities to the Hosgri, Becker wants a re-examination of the seismic standards at Diablo Canyon.

“This is a big heads-up,” she said. “We would be irresponsible if we didn’t take another look at this.”

PG&E officials say Diablo Canyon can withstand earthquakes generated by local faults, though, and say further seismic reviews are unnecessary.

Assemblyman Chuck De- Vore, R-Irvine, has proposed a ballot initiative that would overturn the state’s ban on new nu-clear plants. The law prohibits new plants before a long-term storage solution is found for the high-level radioactive waste generated by nuclear plants. DeVore believes the waste is being stored safely on site and wants the state to be able to move ahead with plans for new reactors.

The initiative has a provision that would bar new nuclear plants in earthquake-prone areas of the state, although it is unclear whether Diablo Canyon would fall into one of those exclusion zones.