Work to dismantle the San Onofre Nuclear Generating Station (SONGS) is well underway, with the demolition of the landmark containment domes expected to finish by 2027, power plant officials said this past week.
After a tour of the nuclear plant, the SONGS Community Engagement Panel provided updates on dismantling efforts, spent fuel transportation readiness, inspections and repair methods during its quarterly meeting on Thursday, Aug. 17.
“These are our three decommissioning principles: safety stewardship and engagement, with safety being No. 1,” said Doug Bauder, vice president of decommissioning and chief nuclear officer with Southern California Edison (SCE).
Roughly 50% of the buildings at the decommissioned power plant have now been taken down, Bauder shared, including two turbine buildings and the intake structure. The domes will be the last to be removed, Bauder explained, because the equipment inside must be removed before they can be demolished.
“So those are the landmarks everybody sees but they’ll be kind of the last visual piece to go down,” Bauder said.
SCE Decommissioning Director Vince Bilovsky explained that most of the work going on currently is inside the containment domes.
“This is the work associated with the downsizing of the reactor vessel internals and those are the parts that are inside the reactor core minus waste Class A, B, C and greater than Class C.” Bilovsky said, adding, “That project’s been going on for about two years now and should come to a close by the end of the year.”
Bilovsky added that by the end of the year, “we’re going to start removing the large components—large components being things like steam generators, fresh risers, reactor coolant pumps.”
“We’re also preparing for the demolition of the auxiliary buildings,” Bilovsky continued. “The auxiliary buildings are those buildings between the two containment domes.”
SCE will also be working to finish removing spent fuel racks.
“So, a lot of big milestones coming up before the end of the year,” Bilovsky said. “We’ve shipped about a quarter of a billion pounds of waste, and there’s a little less than a billion pounds so we’re over 25% … and we’re just about finished with the intake structure demolition and backfill.”
Removal of the reactor vessel and large components will continue until 2025 along with the demolition of the buildings between the domes, Bilovsky said.
“Then the big question about when are we going to knock down the containment domes themselves, well, you see that happening mostly in 2026 and finishing in 2027,” Bilovsky said. “Then it’s really just moving a lot of soil around, grading the property, doing the last of the final status surveys.”
During the presentation, SCE Engineering Manager Jerry Stephenson outlined SCE’s spent fuel management defense-in-depth program, which refers to facilities’ “multiple layers” of protection against accidents and efforts to minimize public risk as much as possible.
The defense-in-depth update primarily focused on the readiness of spent fuel and waste canisters for shipping, inspections and canister repair methods.
“We’ve done some great things here at San Onofre, we’re very proud of the things that we’ve done,” Stephenson said. “For example, the design of the canisters requires a half-inch thick wall, we went with five-eighths-thick walls.”
Stephenson noted that the energy company also used grade 316L stainless steel, which offers “tremendous improvement in corrosion resistance.”
“We won industry awards for our inspection that we developed, and we’ve also developed mitigation that’s leading the industry,” Stephenson said. “I could go on and on but those are some key points.”
Independent Spent Fuel Storage Installation System Engineer and SONGS Program Manager Randall Granaas explained that all the fuel will be ready to go as soon as there’s a place to send it.
While federal officials pursue efforts to establish temporary and permanent repositories to store the nation’s spent nuclear fuel, U.S. power plants, like SONGS, must continue storing their own radioactive waste.
Thursday’s presentation also highlighted industry research and development of mitigation and repair methods for canisters, including cold spray, arc welding, inorganic coating, liquid metal and geopolymer. SCE concluded that cold spray was the leading repair method.
SCE’s Inspection and Maintenance Program includes a “flaw depth of 0.0625” (1/16 inch) as the threshold for fuel canister repairs.”
Responding to a member of the public’s question about SCE’s emergency planning during decommissioning of SONGS, particularly with Hurricane Hillary projected to land in Southern California on Sunday, Aug. 20, the panel noted that emergency analysis for flooding shows that neither a tsunami nor flooding will breach the wall or Holtec storage module at SONGS.
Another community member asked why SCE had not considered reprocessing the fuel at SONGS rather than looking to store the spent fuel.
“Reprocessing fuel to make new fuel is not performed in the United States at a commercial level,” Bilovsky said. “It’s a standard process in other parts of the world. An executive order originally signed by Jimmy Carter prohibits reprocessing in the United States.”
“The concern then and perhaps still now was proliferation of nuclear weapons, although this requires a lot more enrichment than reprocessing for commercial nuclear fuel,” Bilovsky said. “With the political winds blowing more positively on nuclear power, reprocessing could happen in the United States, but would require a legal change to do so.”
Community Engagement Panel Chair David Victor noted that the Navy wants their land back, so “interesting as it might be to put a reprocessing plant up here or a reverse osmosis desalination plant or Disneyland of San Clemente here, none of that’s going to happen.”
“The site will be cleared off, the site will be given back to the Navy, they’re going to turn it back to Camp Pendleton, and they’re going to integrate it,” Victor said.
“Reprocessing could be done at places like interim storage facilities, and that would generate more value and more jobs and make those facilities more attractive, and so will that happen? I don’t know, but that seems to be, politically, one of the possible directions of travel,” Victor continued.
Thursday’s meeting was also Victor’s last meeting as chairperson of the CEP, with Stetson taking on the role.
“Our work is not done,” Victor said. “We have to continue focusing on defense-in-depth, we have to continue with meetings like the ones that are listed up here, we have to continue working on organizing to change federal law, working with our elected officials and patterns in other places around the country.”
SCE offers public walking tours to give members of the community a chance to learn more about the decommissioning process.
“We have found that engaging through tours is a very effective way to share about what’s happening here at the station,” Bauder said.
The next public walking tour will be held Sept. 16.