By John Stang
Southern California Edison (SCE) hopes to restart moving used nuclear fuel to dry storage at its San Onofre Nuclear Generating Station between Jan. 15 and Jan. 20, 2019.
The utility announced that target Thursday at a San Onofre Community Engagement Panel meeting focused on an Aug. 3 mishap in placing a canister of the radioactive material into its storage slot. The incident has halted all fuel transfers at the retired power plant.
“We’re in no rush to restart this unless we can prevent other incidents from happening,” Tom Palmisano, SCE’s representative to the panel, said during the meeting in the city of Oceanside.
Southern California Edison permanently closed the San Diego County power plant in 2013 after faulty steam generators were installed in its two operational reactors. It is waiting on state regulatory approval to begin major decommissioning operations, to be managed by an AECOM-EnergySolutions joint venture.
In December 2014 the utility awarded the defueling contract to New Jersey energy technology company Holtec, which built a new storage pad and is moving the used fuel from wet to dry storage.
On Aug. 3, one canister went off-target and became hung up while being lowered into its slot; the problem was not identified and fixed for nearly an hour. The situation also created the possibility that the canister could have dropped 18 feet and was not reported to the Nuclear Regulatory Commission for three days. The federal regulator subsequently initiated a special inspection of the incident.
The NRC this week submitted its special inspection report to Southern California Edison.
Inspectors specifically identified two “apparent violations”: SCE’s failure to ensure there was backup equipment to prevent the canister from dropping and not reporting the mishap within the mandatory 24-hour period. Those apparent violations are being considered for escalated enforcement, Troy Pruett, director of the NRC’s Division of Nuclear Materials Safety, wrote in a Wednesday letter to Doug Bauder, SCE vice president and chief nuclear officer at SONGS.
The total potential fine for these apparent violations ranges from zero to $72,000. An NRC spokesman said earlier this week he did not believe officials had yet decided on specific penalties or corrective actions.
The NRC notice also cites Severity Level IV violations of safety requirements. Such breaches are of least concern within the agency’s four Severity Levels and do not result in escalated enforcement.
“The violations involved failures to: (1) identify conditions potentially adverse to quality for placement into your corrective actions program; (2) establish an adequate program for training, proficiency testing, and certification for individuals involved in downloading operations; and (3) provide adequate procedures for dry cask storage operations involving downloading operations,” Pruett wrote.
At Thursday’s meeting, Scott Morris, NRC deputy Region IV administrator, said SCE has until Dec. 8 to pick one of two choices on dealing with the apparent violations. The first would be a pre-decisional enforcement conference, which would be open to the public. It would have to take place within 30 days of SCE making its choice. The second would be an alternative dispute resolution, which is a private session with a mediator to determine the violations and fines. The results would be made public. This would have to take place 45 days from SCE’s choice of which way to go.
Since the used fuel transfer began early this year, 29 canisters have been moved to dry storage. Another 44 casks await relocation. The project was originally scheduled for completion by mid-2019. Southern California Edison said Friday it anticipates completing the fuel transfer in 2019.
As one of the 100,000-pound Holtec canisters was ready to be lowered into place on a storage pad on Aug. 3, it was held by two thick straps — each capable of holding 113,000 pounds. This was a redundant safety feature in case one of the straps broke.
Two Holtec workers were with the mobile machinery used to lower the canister into place — an operator and a spotter. It was the first time those employees had performed the procedure. Supervisors and all other personnel were 150 feet away to avoid unnecessary exposure to radiation. The supervisors could not properly see what was happening.
As the canister was being lowered, the spotter was out of position and the operator did not properly watch his instrument panel
The canister went slightly off-target while entering the below-ground slot, hanging up on the shield ring rather than slotting into place.
When the canister hung up on the shield ring, the machinery kept lowering the two straps until the slings bunched up on the ground. That was the loss in redundancy that could be a potential violation.
“We failed to provide proper control and oversight of an activity. … This event was unacceptable. … We own this and Holtec has owned this,” Palmisano said.
A similar incident occurred at SONGS on July 22 when another canister became hung up on the shield ring. But that crew was experienced and immediately spotted the problem, meaning the loading straps did not bunch up on the ground. That crew correctly dealt with the problem, but did not report the incident, Palmisano said
“We really failed to learn from that,” he told the Community Engagement Panel.
Palmisano said one of the causes of the incident was turnover in the past 10 to 12 months of workers moving fuel at SONGS. “People would rotate out. … We didn’t recognize the less experienced people coming in. The procedures and training weren’t adequate,” Palmisano said.
Southern California Edison has worked on improving training for everyone, including experienced workers. Written procedures have become more detailed. More cameras and monitoring screens have been installed for more workers and supervisors to double-check the canister’s movements, particularly since most are stationed 150 feet away because of concerns about exposures to radiation. More supervisors will have to check off on whether produces are done property during a move. A loading machine will have an alarm to signal when the straps go slack.
The utility plans practice runs on the fuel transfer on Dec. 11 and Dec. 17.
Palmisano said the practice canisters are roughly a half-inch narrower than the real ones. Morris told Palmisano that “it makes sense” for SCE use the exact same size of canisters in the dry runs as are used with actual fuel.
Watchdog groups in the area warned against rushing to resume the spent fuel transfer.
“The NRC’s latest report is so alarming that people with heart conditions should avoid reading it. It is a recipe for cardiac arrest,” said Charles Langley, executive director of Public Watchdogs, told the San Diego Union-Tribune. “It says that the two most important workers responsible for loading deadly lethal nuclear waste weren’t tested, properly certified or trained.”
Ray Lutz, with Citizens Oversight, told the newspaper “This review done by the NRC is essentially covering for the utilities. It’s a shame this regulatory agency isn’t doing its job.”