An apparent violation (severity level yet to be determined) was identified that resulted in an
unanalyzed condition for the spent fuel dry storage system.
PPL filled a spent fuel storage cannister with
Argon and
Helium gases instead of using all
Helium gas as required by the Certificate of Compliance No. 1004 for the NUHOMS-52B Dry Cask Fuel Storage System. The
10 CFR Part 72 Technical Specification 1.2.3, "24P and 52B
DSC Helium Backfill Pressure," requires a
helium backfill pressure of 2.5 pounds per square inch (psig) +/- 2.5 psig (stable for 30 minutes after filling). This issue is considered an apparent violation that resulted in an
unanalyzed condition for a storage system designed to prevent or mitigate a serious safety event being degraded to the extent that a detailed evaluation was required to determine its operability. The issue is being considered for escalated enforcement in accordance with the
NRC Enforcement Policy,
NUREG 1600, Supplement VI, "Fuel Cycle and Materials Operations."
