The U.S. Nuclear Regulatory Commission said Friday it is opening a special inspection of a recent mishap in loading used reactor fuel into a storage pad at the shuttered San Onofre Nuclear Generating Station (SONGS) in California.
The announcement comes as watchdog groups in California are demanding action, with one reportedly planning a lawsuit, in response to the incident that has been linked to human error.
Holtec International is moving all remaining spent fuel at the San Diego County plant from wet to dry storage under contract to SONGS majority owner Southern California Edison (SCE). On Aug. 3, workers were inserting a fuel canister into the one of the below-ground silos at the storage pad near the Pacific Ocean. The canister’s rigging went off-target so the container could not go smoothly into the silo, causing almost an hour’s worth of corrective work before the canister was safely inserted, according to a prepared statement from Holtec.
Fuel transfer operations have been paused since then. The suspension will remain in place until the utility is satisfied Holtec has taken all needed corrective measures, said SCE spokeswoman Liese Mosher. In its statement Friday, the NRC said fuel transfer would not resume until its review is finished.
The nuclear industry regulator said its inspection team would start work at SONGS on Sept. 10. It will remain on-site for roughly a week. The broad scope of the inspection, according to an Aug. 17 NRC memo, will include: evaluations of all pertinent documentation and procedures connected to the fuel transfer work; evaluation of corrective measures implemented following the incident; and interviews with personnel associated with the mishap.
“Once the licensee has confirmed its plans to resume fuel loading operations, inspectors will also observe the loading operations to ensure that the corrective actions are adequate,” according to the memo. “These observations may be conducted as part of this special inspection or as an independent inspection activity, as directed by regional management.”
An inspection report will be released no more than 45 days after the inspection is complete. “Any violations found as a result of the inspection would be evaluated using the agency’s normal enforcement process,” an NRC spokesman said by email Friday. The process, which encompasses different levels of severity findings, can lead to issuance of a non-cited violation, notice of violation, or notice of violation and civil penalty.
In a prepared statement Friday, Southern California Edison said it welcomed the NRC review of the incident and “that the ensuing training, processes and procedures for spent fuel canister loading are robust and implemented.”
“SCE remains committed to safety and a rigorous oversight process during decommissioning,” the company said.
Separately, El Cajon-based Citizens’ Oversight on Tuesday sent a letter to the California Coastal Commission calling for a full probe of the incident.
“Edison says there was no risk because computer model testing shows that canisters can be dropped 25 feet without failing,” Ray Lutz, Citizens’ Oversight founder, said in a press release. “However, those models were considering damage to canisters contained in much stronger Transportation or Transfer casks, and not the relatively thin, 5/8” thick stainless-steel interior canister alone.”
Lutz’s group in 2015 sued to block the expansion of SONGS’ dry-storage pad to accommodate used fuel from two reactors shut down two years earlier. That case was settled in 2017, with SCE authorized to continue moving the plant’s used fuel to dry storage while taking a number of steps to locate an off-site storage location.
A separate organization, Public Watchdogs, is planning a lawsuit to prevent transfer of additional used fuel to the storage pad, the San Clemente Times reported Thursday. “I’m not allowed to talk about the strategy, but the (goal) is to get a court-ordered injunction that forbids them from deploying more nuclear waste cans on the beach, and they can’t put it there,” the group’s executive director, Charles Langley, told the newspaper.
Holtec, an energy technology based in Camden, N.J., says it is taking the corrective steps required by Southern California Edison.
In a statement, SCE said: “Holtec was loading the spent fuel canister into the Cavity Enclosure Container (CEC) on the dry cask storage pad when the canister got caught on an inner ring that helps to guide it into place. There is a very snug fit in the CECs, and it is not unusual for it to take the downloading team a few manipulations to get the canister aligned appropriately.”
The workers did not immediately note the problem, which was then identified by oversight personnel from Southern California Edison, according to the statement. The problem was then fixed.
At the Aug. 9 meeting of the San Onofre Community Engagement Panel, David Fritch, a safety inspector at SONGS, said he witnessed the incident and was disappointed SCE and Holtec did not alert the public during the briefing at the beginning of the meeting. “Edison is not forthcoming about what is going on,” he said.
“It was a gross error on two individuals, the operator and the rigger, that were inexplicable,” Fritch said.
Fritch said this type of problem has occurred before, but the more veteran crews are not sharing their experience on dealing with such a canister hang-up with less-experienced teams.
“There was no risk to the spent fuel, no risk to the public. It was a rigging issue,” Tom Palmisano, SCE vice president for decommissioning and chief nuclear officer at SONGS, said during the meeting. The rigger and operator should have recognized they needed to lift up and re-center the canister before lowering it again, he said.
Holtec said the canister was in no danger of an uncontrolled fall. The canister was also designed to fall from a greater height than the 18 feet from the bottom of the storage silo when the incident occurred, according to Holtec and Southern California Edison. The appropriate crew and procedures in inserting the canisters were reviewed about two months ago with no problems found.
“Nevertheless, Holtec views this as an unacceptable occurrence and is taking steps, in consultation with Edison, to ensure that the remedial measures, including supplemental craft training, would be carried out with extreme thoroughness so that a high level of assurance against any conceivable upset in the future is guaranteed,” Holtec said in a prepared statement.
In another written statement, Holtec said the rigging and inserting procedures have been revised to add more detail and check points. That includes updating briefings to ensure the supervisor and crew have a better understanding on conditions, roles, and critical points of the operation. Extra workers will be stationed with good views of the procedures to ensure extra eyes on activity. The lead rigger will undergo extra training regarding behaviors, and communicants. Additional training will focus on this particular type of transfer operations including critical points and communications, the Holtec statement said.
Southern California Edison also requested that Holtec review the incident and improve training and procedures for the loading process.
Southern California Edison in 2013 permanently closed reactor Units 2 and 3 and SONGS rather than replace faulty steam generators. Preliminary decommissioning operations are underway by an AECOM-EnergySolutions team. Reactor Unit 1 at the plant shut down in 1992 and has already been decommissioned, with its fuel moved to the dry storage pad.
Holtec International began the used-fuel transfer early this year and is due to complete the work by the middle of 2019. To date, 29 canisters of fuel assemblies have been transferred, with 44 to go. The radioactive material would then remain on the storage pad until an off-site location for temporary storage or permanent disposal is ready.
Fuel assemblies from Unit 1 were already on the storage pad, which was expanded to store the remaining material.
Southern California Edison hopes the state by the first quarter will give regulatory approval for decommissioning of SONGS.