Operators at California's two nuclear plants said Monday that their facilities can withstand a higher magnitude earthquake than scientists predict could ever strike the plants.
Americans have become increasingly concerned about domestic facilities in the wake of the disaster unfolding in Japan. Earthquakes and a tsunami have damaged at least two nuclear complexes in Japan and officials have declared states of emergency at six of the country's 55 reactors.
The agency also said weather conditions have taken the small releases of radioactivity from the damaged reactors out to sea but given the thousands of miles separating the two countries, no harmful levels are expected to reach U.S. shores.
Now to the two plants in California:
Paul Flake, a spokesman for Pacific Gas and Electric, which operates the Diablo Canyon Power Plant in San Luis Obispo County, said their plant was designed to withstand a magnitude-7.5 shaker. Based on historical studies, scientists say the biggest earthquake near the plant would be a magnitude-6.5, Flake said.
"That's the margin that we have based on our long-term seismic program," he said.
The Nuclear Regulatory Commission has tried to reassure the American public, saying that harmful levels of radioactivity from Japan are unlikely to reach the United States.
Similarly, the San Onofre Nuclear Generating Station in northern San Diego County was designed to withstand a magnitude-7 earthquake, according to Southern California Edison, which operates the nuclear plant. When it was under construction, studies at the time determined that the nearest fault, located 5 miles offshore, was capable of producing a 6.5-magnitude shaker.
A 30-foot concrete seawall also surrounds the plant, which is equipped with redundancy systems should something fail, the utility said.
"The objective is not to continue operating during an emergency, but to shut down safely," said Southern California Edison spokesman Gil Alexander.