Waves crash on the rocks below San Onofre’s tsunami wall, but it’s the only sound.

The pipes that roared when they sucked in 1.8 billion gallons of ocean water a day – pipes as wide as a Cadillac Coupe de Ville is long – are silent. The catch pools that once teemed with fish are still and dark. A cage for errant sea lions rests in a far corner, empty.

“They’d chase the fish in here,” Jim Madigan said of the sea lions and the catch pools.

“We’d put them in the crates and take them to Laguna Beach to be checked out and returned to the ocean,” added Madigan, who has worked at San Onofre Nuclear Generating Station in one capacity or another for 35 years.

“There was more than one repeat visitor.”

Once, San Onofre was a marvel of modern engineering – splitting atoms to create heat, boiling water to spin turbines and creating electricity that fulfilled 18 percent of Southern California’s demand. Now, it’s a demolition project of mind-boggling proportions, overseen by a dozen government agencies.

It’s expected to cost $4.4 billion, take 20 years and leave millions of pounds of spent nuclear fuel on the scenic bluff beside the blue Pacific until 2049 or so, because the federal government has dithered for generations on finding a permanent repository.

In this vacuum, contractors from Holtec International – one of only a handful of companies licensed by the Nuclear Regulatory Commission to do dry-cask radiation storage in the U.S. – are at work. Construction of the controversial “concrete monolith” to protect San Onofre’s stranded waste has begun, over the protests of critics who decry a “beachfront nuclear waste dump.”

THE MONOLITH

The reinforced concrete pad that will support the monolith is finished.

Last week, Holtec workers used cranes and trucks to maneuver the first of 75 giant tubes into place atop it. When those tubes are bolted in, concrete will be poured up to their necks, and they’ll be topped off with a 24,000-pound steel-and-concrete lid. Earth will be piled around it so that it looks something like an underground bunker.

Southern California Edison, which operates the plant, would not share the Holtec contract or reveal its price tag, but San Onofre’s owners have recovered more than $300 million from the federal government for its failure to dispose of nuclear waste, which is why dry-cask storage must be built in the first place. San Onofre’s decommissioning plan sets aside $1.27 billion for future spent fuel management.

This is one of the first newly licensed Hi-Storm Umax dry-cask storage systems Holtec is building in the United States. Once it’s complete – expected to be late next year – workers will begin the deliberate and delicate dance of removing all spent fuel from cooling pools beside each reactor.

The iconic twin domes you see from the highway and the beach don’t reveal their enormity. They stand as tall as a 13-story building, and the adjacent pools holding their spent fuel are 25 feet wide, 60 feet long, about 40 to 50 feet deep and hold a half-million gallons of water.

When Southern California Edison begins removing the 2,668 fuel assemblies chilling there, bays to those enormous pools will open. Holtec storage canisters will be lowered in. Underwater, 37 spent fuel assemblies will be loaded into each canister and capped. The canister will be slipped into a “transfer cask,” lifted from the pool and drained.

Then it will be loaded onto a truck, driven a few hundred yards to the Umax and lowered into one of those 75 tubes. The waste-filled canister will remain inside. The transfer cask will be removed. The tube will be capped.

This will be repeated more than 70 times, until all the fuel in the more vulnerable pools is entombed in more stable dry-cask storage. That’s slated to be done by mid-2019.

TECHNOLOGY

The system will become something of a real-time experiment: Edison is partnering with the Electric Power Research Institute to develop inspection techniques to monitor the casks as they age. The casks’ integrity over time, while holding hotter “high burn-up” fuel, is a major concern of critics.

“Burn-up” – i.e., the amount of uranium that undergoes fission – has increased over time, allowing utilities to suck more power out of nuclear fuel before replacing it, federal regulators say. It first came into wide use in America in the latter part of the last century, and how it will behave in short-term storage containers (which, pending changes in U.S. policy on nuclear cleanup, must be used for longer-term storage) remains a topic of debate.

Tom Palmisano, chief nuclear officer at Edison and vice president for decommissioning, leans over a picture on a computer screen.

The image is a cut-away of a storage cask, and inside the cask’s ventilation ducts is a tiny, motorized camera. One version of the robot can attach to metal surfaces via magnets; another can attach to nonmetal surfaces via suction.

“The tooling to go inside and inspect these things is being developed – it’s an industrywide effort,” Palmisano said. “We’ve got visual inspection capability, and we’re working on other quantifiable inspection capabilities.”

But dry-cask technology is not new, he said. Nuclear power plants in the U.S. have used it since 1986, and an analysis by the Electric Power Research Institute found that it would take at least 80 years before a severe crack could form in a dry storage canister.

The Umax uses the most corrosion-resistant grade of stainless steel; its design exceeds California earthquake requirements, and it protects against hazards such as water, fire or tsunamis.

Critics cast skeptical eyes on those claims.

They don’t disagree that dry storage is safer than the spent fuel pools, but activist Donna Gilmore says officials gloss over the potential for serious cracking – a bigger risk in a moist, salty, oceanfront environment such as San Onofre.

Once a crack starts, it would continue to grow through the wall of the canister, undetected, until it leaked radiation, Gilmore said.

Other countries use thicker-walled casks than those licensed in America, and she believes we should, too.

EYES FORWARD

What everyone wants is to remove the ensconced “stranded waste” from San Onofre as soon as possible, and the only way that can happen is if the federal government takes action.

Palmisano said energy is best expended pushing that forward, not arguing over canisters.

On that front, he is cautiously optimistic.

In January, the U.S. Department of Energy launched a new push to create temporary nuclear waste storage sites in regions eager for the business, currently in West Texas and New Mexico. Several of those could be up and running while the prickly question of coming up with a permanent site is hashed out.

There could be a plan, and a place, for this waste within the next 10 years, Palmisano said – but that would require congressional action, which in turn would likely require much prodding from the public.

“We are frustrated and, frankly, outraged by the federal government’s failure to perform,” he said. “I have fuel I can ship today, and throughout the next 15 years. Give me a ZIP code and I’ll get it there.”

END TIMES

San Onofre’s heavily protected control room was built in an airtight envelope so that nothing outside would affect the people running the reactors. It once glowed with a dizzying array of lights and screens and switches. Now, it’s mostly dark.

The containment domes that protected the reactors are patched where holes were made to install enormous new – some say souped-up – steam generators that were the plant’s undoing. Labyrinths of metal, seven stories high – which once pulsed as high-pressure pipes funneled steam heated to 1,000 degrees – are now cold.

Diablo Canyon, the state’s only other nuclear plant, is slated to close in 2025. An era has come to an end in California.

“Whether you’re for or against nuclear power, it’s really a shame for investors and ratepayers and employees that this facility had to be shut down prematurely,” Palmisano said.

“It was a very viable facility.”

Contact the writer: tsforza@scng.com