Seismic Characterization and Offshore Seismic Research Project at San Onofre

Southern California Edison (SCE) and Scripps Institution of Oceanography at UC San Diego will collaborate on a project to gather seismic data off the coast of the San Onofre Nuclear Generating Station (SONGS). The Scripps team includes experts from around the country to perform the proposed offshore research. Professors Neal Driscoll at Scripps and Graham Kent at the University of Nevada, Reno will co-lead this research effort. The work, part of SCE's seismic research projects for SONGS Units 2 and 3, will involve state-of-the art data-gathering and analysis technologies, and will begin later this year and continue through 2013.

Scripps and University of Nevada, Reno scientists will lead the project, which will include collecting and processing data from 2-D and 3-D multichannel seismic reflection and refraction off San Onofre State Beach. The raw and processed survey data will be open-source and available to other experts to view and use in further studies. This data will also be made available to the general public. Offshore seismic research is conducted with specially equipped boats that tow cables, or streamers, with underwater microphones at regular intervals. Two-dimensional seismic surveys usually have one streamer; three-dimensional surveys have four or more.

"Our number one priority is safety, and seismic safety plays an important role in our operations at the plant," said Caroline McAndrews, SCE director of nuclear strategic projects. "Having Scripps take the lead on this important project will provide us with objective and world-class expertise in geophysics, and increase our understanding of SONGS' seismic setting. This knowledge is key to ensuring the continued safe operation of SONGS."

Besides evaluating the existing and potential faults in the area, the seismic reflection and refraction surveys will image the offshore structures at an unprecedented resolution, and will allow scientists to test the alternative hypotheses for the tectonic deformation observed off San Onofre. In addition, the geophysical surveys will reveal vertical motions of the crust through time, associated with margin reorganization.
Both units of the plant are currently safely shut down for inspections, analysis and tests. Unit 2 was taken out of service Jan. 9 for a planned outage. Unit 3 was safely taken off line Jan. 31 after station operators detected a leak in one of the unit's steam generator tubes.

About Southern California Edison
An Edison International (NYSE:EIX) company, Southern California Edison is one of the nation's largest electric utilities, serving a population of nearly 14 million via 4.9 million customer accounts in a 50,000-square-mile service area within Central, Coastal and Southern California.

About University of Nevada, Reno
Nevada's land-grant university founded in 1874, the University of Nevada, Reno has an enrollment of 18,000 students and is ranked in the top tier of the nation's best universities. Part of the Nevada System of Higher Education, the University has the system's largest research program and is home to the state's medical school. With outreach and education programs in all Nevada counties and with one of the nation's largest study-abroad consortiums, the University extends across the state and around the world. For more information, visit www.unr.edu.