Disaster scenarios considered to nukes in California

California's two nuclear power plants have more than terrorist attacks to workk about. Since they lie on the coastline, natural disasters must be considered.

Six months after the mega-tsunami in the Indian Ocean, fears of a major tsunami on the California coast are spurring scientists to reassess the possible impact on nuclear power plants.

PG&E is planning to spend $500,000 in a new effort to assess how two worst-case scenarios for tsunamis -- the "apocalyptic model" and the "decades-of-terror model," as the utility's top geoscientist, Lloyd Cluff, calls them -- would affect the Diablo Canyon nuclear plant near San Luis Obispo and the decommissioned Humboldt Bay nuclear plant near Eureka.

The 2,300-megawatt Diablo Canyon plant supplies 10 percent of California's electricity. The small Humboldt Bay plant closed for refueling in 1976 and was never restarted. However, like Diablo Canyon, the Humboldt Bay plant still has large amounts of highly radioactive, used nuclear fuel in a storage pool.

"We will model this with the best tsunami models that exist to decide whether we need to do any more (upgrading) with these two facilities" to guard them against tsunamis, Cluff told the state Seismic Safety Commission at its June 23 meeting in San Francisco.

A third nuclear plant, San Onofre, is north of San Diego and is operated by Southern California Edison. Officials there said they are confident the plant is safe from tsunamis. Unlike PG&E, they plan no reassessment of their tsunami risks.