* Four fault lines run near nuclear power plant
* Sonar could harm animals in protected wildlife areas
* Plant operator PG&E still needs federal, other approvals
By John Upton
SACRAMENTO, Calif., Aug 20 A plan to fire
powerful sonar devices and map seismic fault lines off
California's central coast near a nuclear power plant received
key approval on Monday from state officials despite concerns
about its impact on marine life.
The proposed $64 million seismic study was designed to help
Pacific Gas & Electric (PG&E) and its regulators gauge
hazards posed by potential earthquakes near the 2,160-megawatt
Diablo Canyon power plant in San Luis Obispo County, about 183
miles (294 km) northwest of Los Angeles.
The tests are needed to ensure that the waterfront facility
is capable of withstanding an earthquake along one or more of
four nearby fault lines. One of the faults was discovered in
2008 and is not well understood, while others were mapped using
The study had been planned since 2006 but gained a sense of
urgency after an earthquake and tsunami off the coast of Japan
in March 2011 triggered a nuclear meltdown at the Fukushima
Daiichi power plant.
Following the Fukushima meltdown, PG&E began fast-tracking
the seismic study and agreed to delay pursuing federal
relicensing of the 27-year-old power plant until the seismic
study is complete.
Operating permits issued by the U.S. Nuclear Regulatory
Commission for Diablo Canyon's dual waterfront reactors, which
produce about 10 percent of California's power needs, are due to
expire in 2024 and 2025.
Fierce debate over the proposed study has coincided with an
extended shutdown of the only other nuclear power plant
operating in California. The San Onofre plant was taken offline
in January following a radioactive leak and remains shuttered by
its operator, Southern California Edison, a unit of Edison
The sonar tests will help paint a detailed three-dimensional
picture of the seismic fault lines in the area. But they are
controversial because the piercing, around-the-clock underwater
sounds could harm animals in protected wildlife areas and limit
CONDITIONS ON TESTING
The California State Lands Commission voted to allow the
tests to move forward but imposed a raft of conditions,
including restricting the firing of sonar guns and hydrophones
to certain areas and certain months.
"I'm not going to tell you that we won't have some impacts,"
PG&E government affairs official Mark Krausse told the
commissioners on Monday. "Our focus has been on minimizing the
impacts from this work."
Commission Chairman Alan Gordon said the commissioners were
forced to weigh unavoidable impacts of the study with the risks
of an accident.
"The consequences of a nuclear accident at this site make it
absolutely imperative and time sensitive that we get the
information that these studies will provide," Gordon said during
PG&E still needs to secure approval of federal and some
other state agencies before it can proceed but it hopes to
complete the study this winter.