Friday, March 25, 2011

Most of California is not susceptible …

San Onofre The California Coastal Commission takes a look at the Japanese earthquake to determine if similar conditions could affect that state. Short answer: No, but that doesn’t excuse a lack of vigilance or a need for further study:

The vast majority of faults in California, including the San Andreas fault, could not produce a magnitude 9 earthquake.

Most of California is not susceptible to an event of the scale of the Tōhoku Earthquake. Nevertheless, it is important not to become complacent; large earthquakes are inevitable throughout coastal California, and could be devastating in their own right. There is a large population and much infrastructure at risk in central and southern coastal California.

A nuclear emergency such as is occurring in Japan is extremely unlikely at the state’s two operating nuclear power plants.

The combination of strong ground motion and massive tsunami that occurred in Japan cannot be generated by faults near the San Onofre Nuclear Generating Station and the Diablo Canyon Power Plant. Nevertheless, the geologic conditions near those plants are very likely different than previously believed and ongoing study is warranted. This has been understood for at least the past three years, and some of these studies, and the environmental planning process for other such studies, are underway.

We explored this in a earlier post: the subduction fault off the coast of Japan led to the unique attributes of the Fukushima event and there is no such fault in or off the coast of California. There is one that could affect Washington, but that state’s nuclear plant is some 250 miles inland, thus not vulnerable to a tsunami.

However, the commission does call out the need to finish some reports on seismic issues regarding the two California plants:

One of the recommendations in that report is for further detailed investigation not only of the Shoreline Fault, but of the total seismic environment of the plant. These studies are currently underway. The proposed high-energy studies meant to identify seismic characteristics deep below the plant and surrounding area will be subject to CEQA review and will require review and permitting by the Coastal Commission.

CEQA is the The California Environmental Quality Act. Interesting and rather reassuring reading.


The Union of Plumbers, Fitters, Welders and HVAC Service Techs has issued a impressive, footnote-loaded statement about nuclear energy policy in the wake of Japan. Its conclusion:

We fully support the efforts of the industry and the Obama Administration to ensure that safety remains the first and foremost priority for all U.S. nuclear plants, that existing plants have adequate and effective technology and procedures in place to guarantee safety and that plant operators and appropriate governmental authorities are fully prepared for all possible exigencies in the future.

Given the rigorous safety regulations and standards the U.S. nuclear energy industry is committed to, and its excellent safety record, we have no reason to believe that major problems will be found.

However, in the field of nuclear power there is always room for improvement and we encourage the industry and Administration to look for any and all opportunities to make our already-safe nuclear energy program even safer.

How was it put in a different context? Trust but verify.

I don’t have a link for this one yet. I’ll add it when I do.

San Onofre nuclear generating station.


Horizon3 said...

I don't think making presumptions of this nature are wise or prudent, if these plants are on the Western side of the Sierra Madre they are subject to the same types of massive quakes that took out San Fransisco and other cities in the past.
They need to re-evaluate their emergency power supply and ancillary equipment to insure they can survive a flood caused by a tsunami or other sources.And a cooling water source should their present system be interrupted by quake induced damage.

Mark Flanagan said...

Maybe. The San Francisco earthquake is thought to have been 7.9 magnitude and did not - really could not - produce a tsunami. We also have to wait and see what the relative impact of the earthquake and tsunami were on Fukushima Daiichi.

Horizon3 said...

One thing that is painfully obvious at Daiichi, is the failure of the backup generators, had they not been compromised, we would not be having this particular discussion.
I am also sure the the physical structure of the plant has been damaged, either by the quake/tsunami, or the subsequent H2 explosions.
Another is the use of seawater in their efforts to keep water flowing in the cores and water in the spent fuel pools. This action alone has guaranteed the demise of at least 4 of the reactors, they and their steam handling systems are now junk iron.

They saved a few million dollars in not totally enclosing their emergency backup power in a water tight enclosures, but have lost 4 billion or more in ruined plant.
Not a very good trade off in my opinion.