Southern California Edison apparently became confused on how soon it should alert the U.S. Nuclear Regulatory Commission to an Aug. 3 mishap in transferring spent fuel at the San Onofre Nuclear Generating Station (SONGS) in California.
Contractor Holtec International has been moving the spent fuel at the retired nuclear power plant in San Diego County facility from wet to dry storage. On Friday, Aug. 3, rigging for one canister went off target while being placed into an underground storage silo. The result was that a 50-ton canister teetered with slack rigging over an 18-foot drop, which required almost an hour’s worth of corrective work.
Southern California Edison, majority owner of SONGS, did not notify the NRC until late on the afternoon of Monday, Aug. 6.
“SCE made an original determination that the event did not require a report. However, SCE contacted the NRC [Region IV] on Monday August 6th and again on Tuesday August 7th to provide details of the event. It has now been determined that the event is reportable under 10CFR72.75(d)(1) and this late report is being made,” SCE said in a written notification dated Sept. 14.
The NRC finished a weeklong on-site inspection of the incident last Friday, and is now studying the matter — which might include a return trip to San Onofre. The regulator expects to issue a report within 45 days of the end of the inspection and follow-up work.
Agency spokesman Victor Dricks said one issue being studied is whether this incident should be classified as “important-to-safety,” and whether SCE was required to report the mishap to the NRC within 24 hours — meaning no later than Aug. 4.
According to a 2015 NRC memo, the relevant-to-this-incident definition of an “important-to-safety” mishap is whether it could threaten harm to workers or the off-site public. The same memo said there is fuzziness in laying out the exact criteria to officially declare an incident or flaw as “important-to-safety.”
