Coastal Commission staff recommends denial of PG&E seismic testing

November 3, 2012

By KAREN VELIE

California Coastal Commission staff recommended on Friday that the board vote to deny PG&E’s seismic testing permit application and object to its consistency certification, according to a staff report.

Renewal of Diablo Canyon’s nuclear power plant’s operating license requires approval of its consistency certification by the commission. PG&E applied for the certification in 2009. The commission determined the application was incomplete partially because of a need for updated information regarding seismic studies that had been performed by the USGS and PG&E, according to a 2010 letter from the commission.

Then, in the aftermath of Japan’s nuclear calamity, concerns about Diablo Canyon’s nuclear power plant’s ability to withstand an earthquake had the public also demanding more information about neighboring faults. The California Public Utilities Commission then directed the utility to do further seismic testing as part of its license renewal.

PG&E responded by submitting a coastal development permit application and a consistency certification for the first phase of a potential two phase series of high-energy three-dimensional seismic imaging surveys. The survey would occur in the waters offshore of San Luis Obispo County between Cambria and Pismo Beach.

Many of the same groups and members of the public who demanded the testing began questioning its environmental and financial impacts such as the loss of life of a large number of marine species.

“Of particular concern are impacts to the harbor porpoise (Morro Bay stock), whose range is limited to the general project area, and the entire population of which is likely to be subject to behavioral harassment,” commission staff says in the report. “The project would also adversely affect Marine Protected Areas, fish and other invertebrates, involving both physiological impacts as well as economic impacts to commercial and recreational fishing by precluding fishing and potentially affecting fish behavior and biology.”

Before the plant was put into operation, after the discovery of the Hosgri Fault in 1971 by Shell Oil, a long and contentious battle between the state and PG&E ensued raising the cost of construction, first estimated at $320 million, by over $5 billion. As a result of finding the Hosgri Fault, Diablo’s design was changed and the plant was retrofitted to withstand a magnitude 7.5 earthquake.

In 1985, the $5.7 billion plant began producing energy.

In 2008, a second fault dubbed the Shoreline Fault was discovered less than a mile from the plant by U.S. Geological Survey (USGS) geologist Jeanne Hardebeck using data from USGS and PG&E monitors.

Even though the Nuclear Regulatory Commission concluded that Diablo Canyon’s design would withstand a potential earthquake on the Shoreline Fault, “The fault’s major characteristics are largely unknown, e.g., its length, proximity to the plant and relationship to the Hosgri Fault and whether the fault displays could extend beneath the plant,” a California Energy Commission research report says.

In assessing PG&E’s proposal, Coastal Commission staff determined that there was insufficient information available at this time to conclude the proposed testing is the least damaging feasible alternative which includes no seismic testing.

“Finally, regarding the “no project” or “no project at this time” alternatives, it appears premature to conduct the currently proposed survey during the fall of 2012, as other ongoing data collection and analysis efforts by PG&E, the NRC, and USGS are likely to provide even better seismic characterization of the DCPP area in the near future and thereby potentially reduce the need, extent or duration of the proposed survey,’ The staff report says.

The California Coastal Commission will discuss the options at a hearing scheduled for Nov. 14.