David Middlecamp: Diablo was a no-fault deal when vessel inched to hole

PG&E Diablo Canyon construction. Unit 1 was 65% complete and Unit 2 was 25% complete.
Wayne Nicholls
PG&E Diablo Canyon construction. Unit 1 was 65% complete and Unit 2 was 25% complete. 2-14-73 Wayne Nicholls

Atomic energy was a growth industry in the 1960s. In San Luis Obispo County, nuclear electric plants were proposed on the Nipomo Dunes and near Cayucos before construction began at Diablo Canyon. The state was undergoing a dizzying growth cycle and utilities were moving to stay ahead of projected demand.

Pacific Gas and Electric Co. had wanted to build another atomic plant north of San Francisco in the early 1960s at scenic Bodega Head. It had bought property, negotiated rights of way for power lines and dug a big hole for a reactor vessel when it discovered the San Andreas Fault bisected the hole. The realization that this fault was responsible for the Great San Fransisco Earthquake gave the utility pause.

It made the most of a siting debacle by selling the property for use as a public park for $1. The hole would fill with rainwater, creating a haven for birds, and wags dubbed it the Hole in the Head.

Today a recently discovered fault is the subject of study in the waters off Diablo Canyon. Another, the Hosgri Fault, would set back construction timetables at Diablo, but that revelation had not yet surfaced when these photos were made.

More than 35 years ago, construction was moving ahead. It was detailed in the then-Telegram-Tribune on Feb. 15, 1973, by staff writer Elliot Curry, in a story headlined “Big reactor installed at Diablo.”

“A 345-ton reactor vessel was rolled toward its permanent base at Diablo Canyon yesterday at the speed of a snail going uphill.

“The steel reactor vessel, 43 feet high and 17 feet in diameter, will occupy a position at the very heart of the first unit of the PG&E nuclear-fueled power plant.

“The move started yesterday is from the Diablo Canyon storage yard to an opening in the dome-shaped containment structure, most recognizable feature of the plant, which is one of the largest nuclear power sources under construction in the United States.

“The reactor was loaded on the caterpillar running gears of a heavy crane from which the crane has been removed.

“After the reactor is placed in the concrete and steel dome, it will be surrounded by four heat exchangers, often referred to as steam generators.

“When the plant goes into operation, the reactor will contain 93 tons of slightly enriched uranium dioxide fuel pellets. Here the fission chain reaction takes place that provides the energy to heat the water that makes the steam that turns the turbines that produce electricity.

“Unit 1 of the Diablo Canyon plant is now 64 percent complete and PG&E expects to be using power from the unit by 1975. Unit No. 2 is 25 percent complete.”

The rosy cost — estimated about $665 million at the time (about $3.3 billion in today’s money, according to the Minneapolis Federal Reserve Bank) and completion projections would be changed by the public announcement of scientists discovering the Hosgri fault later in 1973.

What were the first and second largest projects in the state alluded to in the article? Water projects? Freeways? The San Onofre nuclear plant? A stadium? The story does not say.

With the expanded construction costs, the plant could place higher on the list. Unit 1 opened in November 1984 and Unit 2 in August 1985.

Visit David Middlecamp’s blog at http://sloblogs.thetribunenews.com/slovault.