The could have withstood the earthquake and tsunami that have devastated Japan, officials with Southern California Edison said today.
, head nuclear officer at the plant, said fail-safe mechanisms in place at the facility, such as the fuel tanks being buried below ground, would prevent the failures that have occurred at the Japanese nuclear installations.
San Onofre is built to withstand up to a 7.0 on the Richter scale, Dietrich said. Though the Japanese quake was an 8.9 to 9.0, Dietrich said the velocity with which the ground was moving at the quake’s strongest point was .35 Gs.
The San Onofre plant, however, can withstand ground movement forces of up to .67 Gs, nearly twice the force of the Japanese quake. This, he said, is a more accurate measure for engineers to go by.
One of the major problems with the Japanese plant was that the 23-foot tsunami wiped out backup diesel generators that run the cooling system at the plant. Dietrich said that wouldn’t happen at San Onofre; not only is the plant protected by a 30-foot reinforced seawall—seven feet higher than the crest of the tsunami that struck Japan—but also, the generators are in water-tight, missile-resistant bunkers that sit at an elevation of 30 feet above sea level.
Furthermore, he said, the fuel tanks for the generators are buried below ground and could not be wiped out by a tsunami, unlike the fuel tanks at the Japanese plant.
A second backup battery-powered system sits at an even higher elevation, Dietrich said.
Another problem Japanese plant operators faced: Dietrich said that in the aftermath of the earthquake, as the reactors shut down, operators injected the system with seawater. The nuclear material and water reacted to create hydrogen gas.
The hydrogen gas ventilation system was apparently compromised by the quake, Dietrich said, leading the flammable gas to explode and compromise one of the reactor's secondary containment domes.
At the San Onofre plant, there is a system in place that re-combines the vented hydrogen to turn it back into water, Dietrich said. Furthermore, the containment dome is airtight and composed of steel plates and several feet of reinforced concrete.
Check back to San Clemente Patch for more details about plant safety and an informational graphic explaining how the plant works.
Correction: Because of a reporting error, the G-force numbers were misstated in an earlier version of this article.