Not that we want to be fault finders, but there are situations where it’s justified.

Say you are siting a nuclear plant. It’s a good idea to know where the fault lines are.

Say there’s a power company that wants a nuclear plant built in San Luis Obispo County, California. Wouldn’t the planners and feasibility study engineers look for seismic faults?

They did. When permits for construction of the Diablo Canyon Nuclear Plant were issued in 1965, reviewers knew about the San Andreas Fault. The said it wasn’t so very close. Californians know about the San Andreas fault, but try not to dwell on it. Or build on it. It isn’t so far from anything in California to be of no importance at all, but these things are relative, in California.

In 1965 no one knew about the Hosgri Fault. That one wasn’t found until 1971, when Shell Oil notices it, not far from Diablo Canyon.

In the world of big energy, Pacific Gas and Electric is a competitor of Shell Oil, and its seismic folks might not have minded all that much shaking up PG&E’s plans. There was a long tussle between PG&E and state government, and Diablo Canyon plant designs were altered extensively. The cost of the plant, originally estimated at $320 million, mushroomed to around $5.7 billion.

Diablo Canyon went online in 1985. Design changes had included allowing for earthquakes as great as 7.5 in magnitude.

In 2008 Jeanne Hardebeck of the U.S. Geological Survey (USGS) found another fault. Using data from USGS and PG&E monitors she mapped the fault, yclept Shoreline Fault. She says its major characteristics remain unknown: length, exact proximity to the nuclear plant and how activity along Shoreline might interact with activity along Hosgri. Might the two shake in tandem, one triggering the other, or reciprocating, if one of the vertical mismatches lost its “friction hold” and slipped vertically?

In that scenario, the amplification could result in shaking more violent than the 7.5 Diablo is supposed to withstand. (We need to remember that the Richter scale is exponential, and that we are dealing with powers of 10, whereby an 8 quake is ten times as powerful as a 7, and 100 times a mighty as a 6. No 10 quake has been recorded, but theoretically it would represent total destruction of everything within a given radius, which I don’t recall; and a 10+ would destroy everything within a radius q0 times as great.)

The Diablo Canyon plant complex is on a bluff far above the Pacific. A tsunami as high as the one that rushed over the Daiichi plant at Fukushima, Japan would not top the cliffs at Avila Beach, and thus would not swamp and shut down its auxiliary power generators.

I remember camping near Avila Beach, and touring San Simeon quite a ways up the hillside. Bluffs in that area would act as a pretty effective seawall.

It is not known whether the fault and its “normal” activity affect strata beneath the nuclear plant and the infrastructure associated with the two reactors and their generators. While that is being sorted out, PG&E’s application for an operating plant permit renewal is on hold. The extension that had been sought was to last 20 years. Suddenly the gloomier Pacific Rim Ring of Fire theorists are suggesting that California might not last that long.

It didn’t help the Diablo Canyon facility’s image that engineers had disabled a back-up cooling system a while back. Oh, not on purpose. It was just one of those human errors that happen in very large projects.

The emergency pumping system was out of commission for 18 months. One of the reactors was offline a while over two years ago when a cooling intake was clogged. The cause was a swarm of jellyfish.

PG&E says the plant has redundant cooling systems. In case of emergency a fall-back system can take over. A crew would open valves manually, and a separate pumping system would go to work.

Nuclear energy is promoted as clean, although those of us who have some acquaintance with West Valley, New York, and the nuclear waste disposal industry facility it once welcomed as an economic boon, might question that. And nuclear energy is relatively cheap, energy companies in that line like to tell legislators and stockholders.

But actually, it isn’t. Nuclear energy generation facilities are very costly to build, so energy companies that want to build them have counted heavily on lavish federal subsidies, which have been made available for every such project to date.

If federal subsidies were dished out on such a scale for other “clean energy” and renewable fuel, not only would Ross Porter already have one going great guns in Smethport, but you and I and a few neighbors would get together and have our own biomass plant, and ours would have a windmill on top.