Japan lesson: Go slow on re-licensing California nuclear plants
Foresight is a quality rarely seen among politicians in
Sacramento, which makes it remarkable that 10 state legislators
actually displayed a lot of it barely two weeks before the
devastating 9.0 Japanese earthquake and the nuclear power plant
crisis that followed.
The group of 10, mostly Democrats, but notably including
Republican state Sen. Sam Blakeslee of San Luis Obispo, fired off a
letter in late February to the U.S. Energy Department’s Blue-Ribbon
Commission on America’s Nuclear Future begging the federal team to
hold hearings in California before the Nuclear Regulatory
Commission (NRC) relicenses the Diablo Canyon or San Onofre nuclear
power plants. Blakeslee’s participation is notable not only because
his party usually wants the wishes of big industries and utilities
rubber-stamped, but also because he’s the Legislature’s lone
geophysicist, with a doctorate in earthquake studies.
Current licenses for both plants run well into the 2020s, but
the owners of each are already working toward relicensing. Pacific
Gas & Electric Co. has applied to renew its permits for both
units at Diablo Canyon, on the coast at Avila Beach in San Luis
Obispo County. That plant’s license was last approved without an
earthquake response plan, because Diablo Canyon is built to
withstand the 7.5 temblor thought to be the maximum possible for
Southern California Edison, operator of San Onofre, is expected
to apply for license renewals at Units 2 and 3 of that plant,
adjacent both to a state beach and the Interstate 5 freeway south
of San Clemente, at the northern edge of the U.S. Marines’ huge
Camp Pendleton base.
The message of the 10 legislators was not necessarily to deny
renewals, but to take them slowly. The same message was echoed just
after the Japanese quake by California’s two U.S. senators,
Democrats Barbara Boxer and Dianne Feinstein.
And why not go slowly, especially after explosions, radiation
leaks and fires rocked Japan’s Fukushima Dai-ichi nuclear power
plant following the big quake and the disastrous tsunami that
slammed ashore a short time later?
For one thing, license expirations are not imminent: the
earliest comes in 2022. Plus, the state of seismic knowledge has
advanced considerably since the two California plants were last
licensed. So a complete examination of their operations is in
order, even if there is no known imminent threat.
“Concern over seismic events at nuclear power plants in
California is not a new issue,” wrote the state lawmakers. They
noted that a nuclear plant at Humboldt Bay was closed for seismic
retrofitting in 1976 because of newly-known earthquake faults and
was later decommissioned.
They also noted that when a 6.8 quake in 2007 jolted Japan’s
Kashiwazaki nuclear facility, the world’s largest, ground motion
nearly doubled the maximum for which that plant was designed. The
latest quake also far exceeded design expectations. How can we be
sure the same thing won’t happen here? the lawmakers asked.
“We believe the seismicity and remaining uncertainty of
California creates concerns,” they said.
What concerns? While both PG&E and Edison have issued
soothing statements since the Japanese disaster about how prepared
their plants are and how they’re designed to take the maximum
possible movement of any known nearby faults, plenty is known today
that was not a few years ago.
For one thing, the U.S. Geological Survey in 2008 reported
discovering a previously unknown “significant” fault directly
beneath Diablo Canyon, meaning there are at least two active faults
in its immediate vicinity. A quake on one fault can sometimes
trigger movement on others nearby, creating more earth movement
than the known maximum for any single fault in the area.
The legislators added that “there is credible reason to believe
that the design basis … approved by the NRC at the time of
licensing (San Onofre) may underestimate the seismic risk at the
site.” This doesn’t make San Onofre unsafe, they said, but it may
mean its margin of safety is less than previously thought.
While no one accuses either PG&E or Edison of deliberately
understating risks, that has happened at other American nuclear
sites, most notably New York’s Shoreham Nuclear Power Plant, where
builders were found by federal investigators to have lied in 1988
about seismic safety factors.
So it behooves Californians and federal regulators not to meekly
accept the statements of the big utilities. They’ve been wrong
before, as when PG&E told the state just prior to the 2008 USGS
report of a new fault that, “We believe there is no uncertainty
regarding the seismic setting and hazard” at Diablo Canyon.
The Japanese crisis, complete with evacuation of half a million
pepople and a radiation quarantine zone extending 19 miles around
Fukushima Dai-ichi, demonstrates that the risks of nuclear power
—- entirely aside from problems with storing radioactive waste
—- dictate going slowly whenever possible. And the long time
frame before California’s two nukes actually need relicensing
mandates not just hearings, but very careful analysis of all
potential hazards and the reliability of all planned safety and