San Onofre Special Inspection Pre-Decisional Enforcement Conference

On January 24, 2019, the U.S. Nuclear Regulatory Commission (NRC) met with representatives of Southern California Edison Company to discuss preliminary findings of a Special Inspection it conducted at the
 San Onofre Nuclear Generating Station following a fuel-loading incident on August 3, 2018.

The meeting was held from 2:00 – 5:00 p.m. Central Time at the NRC’s Region IV office, which is located at 
1600 E. Lamar Boulevard in Arlington, Texas.  It was open to public observation and was broadcast via webinar.  NRC officials answered questions submitted via the Internet from the public following the business portion of the meeting.

No decision on the final safety significance of the findings identified in a November 2019 inspection report or any additional NRC actions were made at the conference.  That decision will be announced at a later date.

Overview of Issues and Inspection

On September 10-14, 2018, NRC officials conducted a Special Inspection at the San Onofre facility in San Clemente, California.  The inspection was conducted in response to the misalignment of a loaded spent fuel storage canister as it was being downloaded into the storage vault at the San Onofre Nuclear Generating Station (SONGS).

Based on the results of the Special Inspection, two apparent violations were identified and are being considered for escalated enforcement action in accordance with the NRC Enforcement Policy.  The apparent violations involved the failure to:

  • ensure important-to-safety equipment was available to provide redundant drop protection features for a spent fuel canister during downloading operations; and,
  • make a timely notification to the NRC Headquarters Operations Center for the disabling of important-to-safety equipment on August 3, 2018.

The circumstances surrounding these apparent violations, the significance of the associated issues, and the need for corrective actions were discussed with San Onofre officials at the conclusion of the onsite inspection and during the final telephonic exit briefing.

Inspection Report

In a December 2018 letter transmitting the inspection findings to San Onofre officials, NRC stated as follows:

The NRC is concerned about apparent weaknesses in management oversight of the dry cask storage operations.  Your staff did not perform adequate direct observational oversight of downloading activities performed by your contractor, ensure adequate training of individuals responsible for performing downloading operations, provide adequate procedures for downloading operations, or ensure that conditions adverse to quality were entered into the corrective action program.  The NRC identified that a causal factor for the misalignment incident involved management weakness in the oversight of dry cask storage operations.

According to NRC’s letter, agency officials determined that three Severity Level IV violations of NRC requirements occurred.  The violations involved failures to:

  • identify conditions potentially adverse to quality for placement into San Onofre’s corrective actions program;
  • assure that operations of importance to safety equipment were limited to trained and certified personnel or under direct supervision; and,
  • provide adequate procedures for dry cask storage operations involving downloading operations.

The NRC determined the issuance of a Notice of Violation is appropriate because the actions to restore compliance have not been fully developed and implemented and the actions must be effective prior to beginning fuel-handling activities.


Southern California Edison owns the San Onofre Nuclear Generating Station.  The plant is located in San Clemente, California.  It permanently shut down in 2013.

A copy of the November 2018 San Onofre Nuclear Generating Station inspection report is available online at  

For additional information, please contact Victor Dricks at (817) 200-1128.