Cascadia's Fault - Jerry Thompson [35]
Around the corner and up the coast from Cape Mendocino, the side-by-side beach towns of Eureka and Arcata were inhabited in 1963 by an uneasy mix of loggers, commercial fishermen, and back-to-the-land idealists who would soon be labeled hippies and environmentalists. The biggest construction project in decades—the atomic power station at Humboldt Bay—was coming to an end and the Pacific Gas and Electric Company (PG&E) was about to deliver a sixty-thousand-kilowatt jolt to the local economy.
Even though terms like meltdown and China syndrome had not yet colored the vocabulary, a tide of negative opinion had already derailed another nuclear plant downstate, so the residents of Humboldt County were aware of the potential for controversy and had mixed feelings about the promise of “power too cheap to meter.” Work at Bodega Head, about fifty miles (80 km) north of the Golden Gate, had been delayed by vigorous opposition for six years. Construction workers had managed to dig a deep hole for the foundations when geologists confirmed that the San Andreas fault ran right beside (some said directly underneath) the reactor site. Eventually, PG&E decided to abandon the project.
Perhaps because the San Andreas veered out to sea at Cape Mendocino, state officials agreed with PG&E that seismic risk would not be an issue on the north coast at Humboldt Bay. With no large earthquakes in the area—at least not since the 1850s, when white settlers started keeping written records of local history—project managers at the utility and engineers who were designing the reactor were convinced the level of risk was within acceptable limits.
The federal Atomic Energy Commission, which would eventually license the plant, defined an active fault as having had one “event” (earthquake) in the past 35,000 years. Or more than one in 500,000 years. AEC regulations in effect at the time specified reinforced, antirupture reactor vessels only when an active fault came within a quarter of a mile (0.4 km) of a plant. But with no detailed information available about the quake history of nearby faults, and with little understanding of the newly discovered Mendocino Triple Junction or the implications of plate tectonics, any seismic threat seemed distant and hypothetical. Not a problem at Humboldt Bay.
“The plans for it were being developed as Tuzo Wilson’s first papers on plate tectonics were coming out,” Lori Dengler told me. As a professor of geology and then department chair at Humboldt State University, she studied the plant’s history and the simultaneous dawning of awareness of Cascadia’s fault. “There was absolutely no inkling of a subduction zone or great earthquakes,” she said. PG&E, trusting the best science available at the time, signed a contract to build the reactor six miles (10 km) south of Eureka.
After the showdown at Bodega Head, the Humboldt plant became a test case for PG&E. Company officials and state and federal politicians no doubt wanted to prove that atomic power could be harnessed safely. The reactor started boiling water and generating electricity for the northern California grid in August 1963. Less than a year later, however, two plates shifting on a fault in Alaska focused worldwide attention on tectonic theory and sparked intense debates about seismic risk on the West Coast. Indirectly this heightened awareness would ultimately shorten the lifespan of the power plant near Eureka.
Ironically, it was the tsunami rather than the earthquake that hit home first.
When the Good Friday earthquake of 1964 wrecked the south coast of Alaska, it sent a train of waves crashing down the coast all the way to California and into the streets of Crescent City, where more than a dozen people were killed. Crescent City is only an hour’s drive north of the reactor on Humboldt Bay. Yet the vulnerability of the power plant to a similar wave or to a massive seismic rupture (or even