The magnitude 6.0 earthquake centered in Southern Napa County this month has again brought the issue of seismic risk at the Diablo Canyon nuclear plant near San Luis Obispo onto the news pages.
Reporting by the Associated Press has revealed a deep internal rift at the Nuclear Regulatory Commission. Officials in the agency are at odds about the ability of the PG&E-owned power plant to withstand a tremor that was much greater than original design criteria. The magnitude 9.0 earthquake-tsunami event of 2011, which triggered meltdowns at three of five nuclear reactors at the Fukushima Daiichi plant in Japan, prompted the NRC to review seismic issues at all of its U.S. plants.
With Diablo Canyon sited near the coast in a vulnerable area, PG&E says a string of modifications has vastly improved the plant’s capacity to withstand seismic tremors. But the final word from the NRC won’t come down for months until an assessment of the seismic risk posed by newly-discovered faults a few miles offshore are completed.
While the giant utility, the NRC and state regulators weigh options, a lot has been happening in the SLO County economy. For one thing, a proliferation of tech companies in software, services and digital marketing has begun to supplant Diablo Canyon, once the only game in town for well-paying, head-of-household jobs that did not involve real estate, government or working at Cal Poly.
Meanwhile, hoteliers and property owners have pitched in to protect a pristine portion of Pismo Beach because they realize that preserving the natural environment of SLO County is worth billions of dollars in future tourism revenue.
It seems likely that Diablo Canyon will face substantial headwinds in extending its license beyond the mid-2020s. Beyond seismic risk, state regulators don’t like the use of seawater for cooling if warmer water is put back into the ocean. The smart play would be for SLO County to begin contingency planning for what to do about replacing the jobs that would eventually be lost when the plant shuts — initially jobs likely would increase due to waste mediation and other activities — and for PG&E to begin thinking about where it will generate so-called baseload electricity to provide power to some 2 million California homes.
The internal debate within the NRC about Diablo Canyon shows there are no easy answers to the problem of jobs, nuclear waste, economic impact and alternative sources of power. But now is the time to begin asking the questions.