At 1930 EDT, on September 11, 2020, Palisades Nuclear Plant was conducting ultrasonic data analysis from reactor vessel closure head in-service inspections. During this analysis, signals that display characteristics consistent with primary water
stress corrosion cracking were identified in head
penetration 34. No leak path signal was identified during ultrasonic testing.
The plant was in cold shutdown at 0% power and in Mode 6 for a refueling outage at the time of discovery. Repair actions will be completed prior to plant startup from the outage.
This condition has no impact to the health and safety of the public.
This report is being made in accordance with 10 CFR 50.72(b)(3)(ii)(A) for degradation of a principal safety barrier. This is the only indication that is currently present, however, if additional indications are found, they will also be repaired prior to the plant startup.
The licensee notified the NRC Senior Resident Inspector.