On November 10, 2018, during a planned bare metal visual inspection of the reactor head,
boric acid was discovered at a
CRDM [Control Rod Drive Mechanism] nozzle to reactor head
penetration. Investigation of the source of the
boric acid is ongoing. The plant was in cold shutdown at 0% power and Mode 6 for a refueling outage at the
time of discovery. Repair actions will be completed prior to plant startup from the outage. All other reactor vessel head
penetrations have had a bare metal visual inspection completed with no other indications identified.
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.
The licensee notified the NRC Senior Resident Inspector.