By John Stang
With a combination of reluctance and unanimity, the California Coastal Commission voted 10-0 Thursday to approve an inspection-and-maintenance plan for on-site storage of spent reactor fuel at the San Onofre Nuclear Generating Station (SONGS).
The plan is a requirement of the coastal development permit the commission issued in 2015 to SONGS majority owner Southern California Edison. It allowed the utility to expand the dry-storage pad to accommodate all spent fuel from all three retired reactors at the San Diego County power plant.
While Edison developed the plan, the commission required it be reviewed by an independent third party — LPI, a nuclear engineering consulting firm.
The plan’s purpose is to ensure the 73 casks holding spent fuel rods from two of SONGS’ three reactors remain intact and leak-free through 2035 — a date by which Edison hopes to have shipped the fuel elsewhere.
Fifty-one casks of used fuel from reactor Unit 1, which closed in 1992, were already in storage. The commission-approved addition to the independent spent fuel storage installation (ISFSI) made space for 73 newer casks holding rods from Units 2 and 3, which closed in 2013 following installation of two faulty steam generators. The inspection plan only covers the casks from Units 2 and 3.
As of Thursday, 69 of those 73 casks were in just-underground storage at SONGS. The remaining canisters are expected to be moved by early August by contractor Holtec International.
The dry storage site is roughly 100 feet from the Pacific Ocean, which has created fears of rising sea levels and tsunamis flooding the canisters — leading to the creation of the inspection-and-maintenance plan.
Edison’s plan, tweaked by LPI, calls for:
- Any scratch deeper than 0.0625 inch in a cask to be repaired — roughly half of the depth that Edison’s original plan called for. The plan calls for metallic overlays to be sprayed on the flawed areas of a cask.
- Beginning in 2024, two spent fuel canisters must be inspected by robots every five years.
- A “test canister” without any fuel will be stored in conditions simulating the conditions of a dry storage site, and will be inspected every 2.5 years as a means of monitoring conditions facing a cask in an above-ground environment.
The plan also takes into consideration that SONGS’ dry-storage license must be renewed by 2034 by the U.S. Nuclear Regulatory Commission.
“The plan is probably adequate and it complies with our conditions” of the 2015 permit, Coastal Commission Chairman Stephen Padilla said Thursday ahead of the vote.
Commissioner Sara Aminzadeh added: “Commissioner Padilla said the plan is ‘probably adequate.’ Probably adequate is not the standard that we all want to meet.”
The commission vote followed a nearly five-hour public hearing, conducted via Zoom. Seven watchdog groups and 14 individuals testified against the plan, while the Nuclear Energy Institute industry group, a city council member from San Juan Capistrano, and six individuals, including three members of the Edison-sponsored SONGS Community Engagement Panel, testified in support.
The Surfrider Foundation presented the most detailed recommendations to change the plan — none of which were adopted Thursday. These included increasing the frequency of robotic testing of canisters and the number of canisters tested.
The organization also wanted additional testing of the metallic overlays being used to fix scratches, which critics fear could expand to eventually cause radiation leaks. The scratches – which critics often refer to as “gouges” – are caused by the transfer of the casks form wet to dry storage, including inserting the 50-ton cans into tightly fitting vertical holes. The deepest scratch found on a SONGS canister was 0.026 inch in depth, compared to the thickness of the canister wall -– five-eighths of an inch.
The scratch issues surfaced after an August 2018 mishap in Holtec International’s loading of a spent fuel canister into storage. The canister went off-target and became hung up on a ring while being lowered into its slot on the storage pad. For about an hour, the 50-ton container was at risk of being dropped nearly 20 feet. The incident stopped fuel movement for 11 months while Holtec and Edison studied the problem and revamped numerous procedures. It also generated a federal investigation and $116,000 fine against Southern California Edison.
The San Clemente-based Surfrider Foundation also wanted “triggers” — such as sea levels rising quicker than expected — to prompt the removal of the canisters from the dry storage site. And it wanted a hot cell installed to hold canisters that must be inspected or resealed.
Most of the critics who spoke Thursday called for a specialized hot cell for that purpose, along with keeping a cooling pool at SONGS in case a damaged canister has to be moved out of dry storage
“The idea of doing anything without a hot cell is frightening, is insane,” said Carole Hisasue of Mothers for Peace.
Tom Palmisano, chief nuclear officer for Southern California Edison, said the safest way to inspect and deal with leaks and deep scratches is with robots in the dry storage chambers — saying that approach shields the workers the most from radiation. Also, leaks and scratches would likely be localized on small area of canisters, which he said are made of a stainless steel that resists corrosion and prevents cracks from spreading.
Andrea Kock, director of the NRC’s Office of Nuclear Material Safety and Safeguards, said during the meeting “needing a hot cell to repair a cask is unlikely.”
Several commissioners voiced unhappiness with a dry storage site so close to the ocean, with no sure plan for removing the used fuel. But some panel members also said they were persuaded by the rationales from the NRC and Edison against the hot cell and pool recommendations.
Infrastructure and environmental services specialist North Wind expects to complete a strategic plan for Edison by December 2020 on how to move used the nuclear fuel off-site.
North Wind’s plan is supposed to tackle the conditions of transferring ownership of the fuel to the shipper, which could be the federal government or a private company. North Wind is also looking at Edison’s preparations necessary to ship the fuel. The plan will further consider whether the fuel would be transported by truck or rail, as well as the time frame and commercial arrangements for that transportation.
Development of the strategic plan was one aspect of Southern California Edison’s commitments in 2017 to settle a lawsuit filed by a local watchdog group against the expansion of SONGS’ dry-storage pad under the state permit.
The NRC is reviewing license applications from Holtec and a separate corporate team to build interim storage facilities in New Mexico and Texas for used fuel from nuclear power plants around the country. With federal approval, the facilities would notionally open within the next few years. Meanwhile, the proposed national permanent nuclear waste and fuel repository in Yucca Mountain, Nev., remains stalled indefinitely.
The Coastal Commission members noted that their panel has no say in the national issues — adding that the inspections-and-maintenance plan is needed at SONGS. Two commissioners —Padilla and Mike Wilson — described their votes as “Boo, yes.” Padilla added: “It is a no-win for all of us.”
Editor’s Note: An earlier version of this article misstated the number of used-fuel storage casks covered by the new inspection plan.
