The following information was provided by the licensee via phone and email:
At 1127 CDT on 5/16/2023, during the reperformance of test procedure 'STS PE-006, Charcoal Adsorber In-Place Leak Test' due to a failure from the previous day, both trains of emergency exhaust were rendered inoperable due to incorrect performance of the procedure. Performers incorrectly de-energized the humidity control heating coil for the unit not under test, rendering it inoperable. This issue was identified and rectified at 1138 CDT on 5/16/2023, exiting the LCO [limiting condition of operation] for both trains inoperable at that time. There was no impact to the health and safety of the public.
- * * RETRACTION ON 6/5/2023 AT 1132 EDT FROM JASON KNUST TO HOWIE CROUCH * * *
The initial failure of the STS PE-006 test was caused by a malfunction of the test equipment which initially injected excessive amounts of tracer gas and caused saturation of the charcoal. Using test equipment sourced from Callaway, and following guidance from the vendor, STS PE-006 test was successfully passed on 5/17/2023. No maintenance or intrusive testing was performed on the unit between initial test failure and satisfactory completion of the test. Because this train of emergency exhaust was not actually inoperable at the time the second train was rendered inoperable due to incorrect procedure performance, there was no loss of safety function. Therefore, this event notification is being retracted.
The licensee has notified the NRC Resident Inspector. Notified R4DO (Gepford).
