Driving along Interstate 5, the San Onofre Nuclear Generating Station — called SONGS for short — still looks as imposing as ever from a distance.

But the power plant, which hasn’t produced electricity in nine years, is being demolished and an up-close tour of the 84-acre site offers a glimpse into what’s involved in gutting an operation of such considerable size.

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“There’s years of planning and years of execution,” said Amanda Wood, who manages waste for SONGS Decommissioning Solutions, the general contractor for the project. “It’s really about planning and coordination between all the different groups.”

Trucks constantly whiz by. Excavators lift and move debris. On the plant’s east side, all that remains of the four-story administrative building that for decades housed offices and conference rooms are rows of thick concrete walls that rise vertically to meet the sloping earth above. They look like bombed-out buildings from World War II.

The decommissioning of SONGS is expected to take roughly eight years to complete and cost about $4.5 billion. Upon completion, just over 1 billion pounds of equipment, components, rebar, concrete, steel and titanium will be removed from the site. About 80 percent is considered radioactive.

By the time the dismantlement is done, only a handful of structures will remain.

Southern California Edison has operated the plant since it opened in 1968 and the utility has hired a contractor to lead the demolition effort. SONGS Decommissioning Solutions is a joint venture of Los Angeles-based engineering company AECOM and a Salt Lake City firm called Energy Solutions that specializes in disposing of nuclear material.

After Edison received the necessary permit in October 2019 from the California Coastal Commission that cleared the way for dismantlement, initial work began in early 2020. Since then, the pace of activity has picked up and thus far 26 of 62 structures have been demolished.

As per an executive order signed by former Gov. Gray Davis, all the rubble from decommissioned nuclear power plants in California must be shipped out of the state.

The vast majority of the plant’s debris is labeled Class A waste, the lowest level of radioactive material. Most of the rubble will go to a disposal facility in Clive, Utah — primarily shipped by rail car, although some material will be transported in casks by truck. Class B and C low-level waste gets sent to a site near the town of Andrews in West Texas. Non-radioactive material goes to Arizona.

“Even our electronic waste, which you can typically recycle, we ship to Arizona,” said Jim Peattie, Edison’s general manager of decommissioning oversight.

He pointed to a giant mound of crushed concrete near the south end of the plant.

“This is all the rubblized concrete that’s been pulled up from all the different foundations,” Peattie said. “They demolish it and take it down and the excavators manage it in smaller pieces ... They break it up and take the steel out of it and then put it in a crusher.”

The crushed concrete is then loaded onto the rail cars that can haul as much as 200,000 pounds of material.

So far, more than 1,200 rail and truck shipments have left the site, carrying 60 million pounds of waste. There is one rail line in and one line out of the plant.

But with workers fast dismantling the facility, crews are now laying down additional tracks to accelerate shipments. By the time they’re done, seven lines will circulate within the perimeter of the plant.

“We have such a small footprint here that once we start generating this waste, it has to go somewhere. We would run out of space,” Wood said. “We have increased the rail capacity so we can have about 50 rail cars on site at any time,” up from about 8 rail cars now.

The extra capacity will increase the rail shipments from 15 per week to as many as 30.

Crews have started work on removing each reactor vessel from Unit 2 and from Unit 3. The vessels each weigh more than a million pounds and are about 25 feet tall and 16 feet in diameter.

Since the internal parts of the vessels were close to nuclear fuel, they are classified as low-level radioactive waste. That means the process of cutting and retrieving the pieces is done underwater. To do that, each cavity is filled with about 500,000 gallons of treated, demineralized water.

Operated remotely by a crew using underwater cameras, the components of the reactor vessel are pulled out one by one, and then cut into pieces with a rotating saw. Using robotics, the pieces are then retrieved and placed into containers. The operation requires a crew of 12 to 20.

It sounds almost like science fiction but the process has been used at other decommissioned nuclear plants across the country, such as Zion in Illinois, Connecticut Yankee in the Northeast and the Trojan Nuclear Power Plant in Oregon.

The most distinctive feature of SONGS is the twin containment domes of Units 2 and 3, each one 190 feet high and clearly seen by drivers on I-5, pilots in the air and sailors in the Pacific.

Once everything inside the domes is removed, they will come down — probably around 2025.

But there won’t be some dramatic implosion. Instead, the domes will come down gradually, from the bottom up. Workers using hydraulic hammers will chip at the 160-foot wide circumference and, in stages, each dome will eventually collapse. The entire process will take about a year.

“The contractor will bring in excavators and literally just hammer away at the side of the building in 6 or 8t-foot lifts, all the way around, until it gets weak enough that it just kind of falls down and drops,” said Ron Pontes, manager of Decommissioning Environmental Strategy with Southern California Edison. “Then they’ll muck out all the concrete and rebar and stuff. And they’ll do it over and over again until the building slowly collapses.”

When the work is done, only a few structures will remain.

The most notable will be two dry storage facilities on the north end of SONGS that contain spent fuel assemblies — the highly radioactive material that generated 2,200 megawatts of electricity when the plant was up and running, enough to serve about 1.4 million homes at any one point in time.

One storage site holds 73 stainless steel canisters of waste that have been lowered into protected vertical cavities. Another 50 sit horizontally at the other storage facility, which was built years earlier. An additional 125 tons of radioactive material from the dismantlement efforts will be placed into 12 horizontal canisters and taken to the dry storage site. Personnel in a security building will monitor all the canisters.

The only other structures will be a seawall 28 feet high, as measured at average low tide at San Onofre Beach; a walkway connecting two beaches north and south of the plant, and a switchyard with power lines. A substation without transformers, the switchyard stays because it provides a key interconnection for the power grid serving San Diego and Orange counties.

The dry storage facilities have been controversial. Some critics say the canisters are not thick enough to withstand cracking and degradation over time. Edison and the canisters’ manufacturer insist they are safe and robust.

Why do the canisters stay behind? It’s a problem that is not unique to San Onofre.

Until the federal government fulfills its commitment to find a repository for waste from commercial nuclear facilities, plants across the country are left keeping their spent fuel on-site. About 86,000 metric tons of spent fuel has stacked up at 75 operating or shutdown nuclear plants in 33 states, according to the General Accounting Office. SONGS accounts for 3.55 million pounds of spent fuel at its storage facilities.

Completing such a complicated project requires a tremendous amount of labor, coordination and skill, and some critics have expressed skepticism that Edison can pull off such a mammoth undertaking without major mistakes.

After all, it was a leak in a steam generator tube in 2012 that led to the shuttering of SONGS.

And in 2018, a 50-ton canister filled with fuel assemblies being lowered into the new dry storage facility was left suspended on a metal flange about 18 feet from the floor of its storage cavity, unsupported by rigging and lifting equipment. The canister was eventually lowered safely but the Nuclear Regulatory Commission later fined Edison $116,000.

“Edison has only committed to doing what is ‘commercially reasonable’ to handle nuclear waste that has been stranded at San Onofre,” Gary Headrick, co-founder of the environmental group San Clemente Green, said when the dismantlement project started. “Their current wishful plan might just work, but what if it doesn’t, like so many other past examples you could point to?”

Pontes said Edison has “taken those lessons” from the past and put in oversight measures to make sure the contractor is “safely carrying out this work.”

“We recognize we have our reputation at stake here,” Pontes said. “I regularly attend meetings with the senior level management at Edison and they’re not pushing anything except making sure we do things safely and we do it right.”

The roughly $4.5 billion price tag to dismantle SONGS comes from existing decommissioning trust funds. The money has been collected from ratepayers and invested in dedicated trusts. According to Edison, customers have contributed about one-third of the trust funds while the remaining two-thirds have come from returns on investments made by the company.

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