Are California's Nuclear Power Plants Built to Withstand Earthquakes?

Editor's Note: A version of this opinion piece originally published on Venice Patch. We decided to share the writer's sentiments with Manhattan Beach residents.

Looking at the failure of three cooling systems at nuclear power reactors in Japan, and a second containment building explosion, I can’t help but wonder about the shortsightedness of building nuclear plants near an earthquake fault. The question arises, are we at risk here in Southern California?

The San Onofre Nuclear Power Plant was built to withstand a 7-magnitude earthquake, whose epicenter would be within five miles of the plant, according to Southern California Edison officials.

More problematic is the aptly named El Diablo Canyon Power Plant, about 200 miles up the coast from Manhattana Beach in Avila Beach. It’s a good place to build a power plant, except for four earthquake faults in the vicinity.

The design was considered safe enough to resist shaking from the nearby San Andreas Fault when construction began in 1968. But then a new fault was discovered in 1973 three miles off shore, the Hosgri fault.

And a few miles farther out, it had produced a 7.1-magnitude quake in 1927. Yet construction at El Diablo continued.

Tens of thousands of protestors gathered to block the plant's construction in 1979, according to reports in The Journal of American History. The plant was ultimately finished with a design intended to withstand a 7.5-magnitude earthquake. It went online in the mid-1980s.

The nuclear power plant on the coast to the north of Manhattan Beach, and the one to the south, are designed to resist a 7.5 and 7.0 quake respectively—to put this in perspective, the plants would be safe in an earthquake the size of the one that hit Haiti last year.

They would not be safe in an earthquake as big as the one that leveled San Francisco in 1906, which was a 7.8-magnitude.

Because the Richter Scale is logarithmic, each whole number represents a change in earthquake amplitude by a factor of 10, but that only tells part of the story. As an estimate of energy expended by a quake, each whole number represents about 31 times more energy than the amount released by the previous number, according to the U.S. Geological Survey.

Experts are predicting that the next earthquake on the San Andreas Fault could reach 8.1-magnitude.

When? The San Andreas fault is "locked and loaded. It's been a long time since an earthquake has occurred on that fault—over 150 years," said Thomas Jordan, director of the Southern California Earthquake Center.

We are being reassured that quakes of around magnitude 8 are the most we could expect in California because the fault geology is different here than it is in Japan. The biggest quake recorded in California history was the 1857 Fort Tejon earthquake, on the San Andreas fault, which reached 7.9-magnitude, according to the USGS. 

But last week's 8.9-magnitude earthquake was the biggest in Japanese history, and now estimated to have killed more than 10,000 people.

President Barack Obama has mentioned that he supported new nuclear power plant construction to help wean us off fossil fuel dependency. Yet if we learn anything from the disaster in Japan, any additional nuclear plants should be in areas more seismically stable than El Diablo Canyon.

My heartfelt good wishes go out to the Japanese people. They have suffered a devastating blow and could use our help and prayers.

After earthquakes in close succession around the Pacific ring of fire, first in New Zealand and now Japan, I hope that California's faults remain quiescent.