The U.S. Nuclear Regulatory Commission said this week that Southern California Edison (SCE) has taken significant steps to address the failures that led to a mishap last year in the transfer of used fuel at its San Onofre Nuclear Generating Station (SONGS). However, the agency also cited the utility for five minor violations of safety requirements.
From January to April, NRC personnel conducted a supplemental inspection to its initial probe of the August 2018 incident at the retired nuclear power plant in San Diego County.
“The NRC determined that your staff’s causal evaluations to address the previously issued violations were adequately performed to the depth and breadth required,” Greg Warnick, chief of the Reactor Inspection Branch in the NRC’s Division of Nuclear Materials Safety, wrote in a July 9 letter to SCE Vice President and Chief Nuclear Officer Doug Bauder. The company also took corrective actions in several key areas for the fuel loading, he said.
Southern California Edison permanently retired SONGS’ last two operational reactors in 2013 . The company hired Holtec International to move the reactors’ used fuel from wet to dry storage. Last August, one canister of fuel assemblies was left at risk of a nearly 20-foot drop for nearly an hour after it became stuck on the shield ring to its underground storage slot.
In March, the NRC fined the utility $116,000 after a special inspection that identified two violations of federal nuclear safety rules: failure to deploy backup gear to prevent a canister drop and failing to alert the regulator to the event within 24 hours.
This year’s supplemental inspection identified five Severity Level IV, non-cited violations by SCE: “failures to: (1) ensure appropriate quality standards on new equipment for downloading/withdrawal operations; (2) ensure purchased material conformed to the procurement documents for load sensing shackles; (3) ensure the loaded transfer cask and its conveyance was evaluated under the site-specific design basis earthquake; (4) provide adequate written basis for the initial 10 CFR 72.48 scratch evaluation; and (5) request the certificate holder to obtain a Certificate of Compliance amendment for use of the intermediate shelf in the spent fuel pool.”
None of the violations would lead to another fine.
“The report reaffirms the NRC’s previous statement that fuel transfer operations at San Onofre can safely resume,” according to a statement from SCE, which said it is continuing preparations for resumption.
