|NO SEISMIC ANALYSIS FOR CANISTER TRANSPORT PROCESS
"During follow-up reviews resulting from the Aug. 3, 2018 canister downloading event (EN#53605), Southern California Edison [SCE] became aware of a condition where, during short periods of the canister transport process, the Vertical Cask Transporter (VCT) could have been operated without a supporting seismic analysis while transporting loaded canisters for storage. SCE has decided to conservatively report this issue.
"The VCT is a mobile gantry crane that is used to transport and download fuel canisters into an Independent Spent Fuel Storage Installation (ISFSI) enclosure. Twenty-nine canisters have been downloaded into the San Onofre nuclear plant ISFSI in this manner since January, 2018. The Holtec UMAX Certificate of Compliance requires that lifting of a loaded spent fuel canister must be performed with redundant (i.e., single-failure-proof) load drop protection features. Inherent in the definition is the ability to withstand seismic loading. SCE identified that although applicable rigging and downloading procedures were followed, a supporting seismic analysis should be developed for the short duration periods in the process where the canisters are transitioned to rigging.
"Southern California Edison has directed its vendor, Holtec, to perform this further seismic analysis. While the additional analysis may conclude that the VCT is stable and functional during these transitioning periods, SCE will work with the vendor should modifications to the canister transport process become necessary.
"SCE is making this notification in accordance with the requirements of 10 CFR 72.75(d)(1). There was no seismic event that resulted in damage to the VCT or a spent fuel canister during the fuel transfer campaign. All 29 spent fuel canisters are currently in safe storage within the ISFSI."
* * * RETRACTION FROM TIM CUSICK TO DONALD NORWOOD AT 1930 EDT ON 4/2/2019 * * *
"On 4/2/19, Southern California Edison (SCE) is retracting San Onofre Nuclear Generating Station (SONGS) Event Report 53858 dated February 2, 2019 for the Independent Spent Fuel Storage Installation (ISFSI). SCE conservatively submitted the event report under 72.75(d)(1) after it was initially determined the Vertical Cask Transporter (VCT) may have been operated for short periods of time during the canister transport process without a supporting seismic evaluation, contrary to the requirements of the Certification of Compliance (COC). A revision to the calculation by the vendor has subsequently confirmed the transport process and VCT operation met the seismic requirements of the Holtec COC. Therefore, Event Report No. 53858 is retracted."
Notified R4DO (Gaddy) and via E-mail IRD MOC (Kennedy) and NMSS Events Notification E-mail group.