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On November 11, 2018, during ultrasonic data analysis from reactor vessel closure head in-service inspections, signals that display characteristics consistent with primary water stress corrosion cracking in head penetration 33 were identified. No indications of boric acid leakage and no surface indications were detected at this location during bare metal visual inspection.

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. The licensee notified the NRC Senior Resident Inspector.

On May 2, 2017, during planned inspections, an ultrasonic examination performed on weld PCS-4-PRS-1P1-1, revealed an axial indication in the pressurizer nozzle to safe end area of the weld. This indication does not meet applicable acceptance criteria under ASME, Section XI. The plant was in cold shutdown at 0% power for a planned refueling outage at the time of discovery. The condition will be resolved prior to plant startup. This condition has no impact to the health and safety of the public. The licensee notified the NRC Senior Resident Inspector. This report is being made in accordance with 10 CFR 50.72(b)(3)(ii)(A), since an indication was found that did not meet acceptance criteria referenced in ASME Code, Section XI.

• * * RETRACTION ON 5/9/17 AT 1303 EDT FROM BARBARA DOTSON TO BETHANY CECERE * * *

Additional evaluations of the recorded indication concluded that the indication was attributed to an erroneous ultrasonic response. This was the result of a combined effect of compromised surface contact at the area of the recorded indication and associated examination scan speed. The contact issue is attributed to the specific tooling configuration required for this exam. The combination of these factors resulted in the introduction of an erroneous reflector in the area of interest that had characteristics of a relevant indication. The vendor repeated the entire examination for axial flaws and there were no service induced indications recorded. A review of the newly acquired data by site, vendor and EPRI personnel confirmed that no service induced flaws are present. The licensee has notified the NRC Resident Inspector. Notified the R3DO (Hills).

On 10/16/04, with the Plant in Mode 6, Nuclear Management Company identified through wall cracks in the inconel buttering adjacent to the J-weld on reactor head penetrations 29 and 30. Ultrasonic examinations of the reactor vessel head were being performed in accordance with the First Revised Order, EA-03-009. The ultrasonic examinations identified leak path detection indications. Therefore, in accordance with the Order, a bare metal visual inspection of the exterior of the reactor head was performed. No evidence of leakage was discovered. A dye-penetrant examination was then performed. The dye-penetrant exam showed minor surface indications that required further examination. Following minor excavation of the weld surface, the through wall cracks were identified. This condition was determined to be reportable at 1730 EST for penetration 30, and at 1915 EST for penetration 29. This notification is being made in accordance with 10 CFR 50.72(b)(3)(ii)(A). Reactor head penetrations 29 and 30 will be repaired prior to placing the reactor vessel head back in service. The licensee notified the NRC Resident Inspector.

• * * RETRACTION ON 11/19/14 AT 1434 EST FROM TERRY DAVIS TO DONG PARK * * *

On October 17, 2004, Nuclear Management Company notified the NRC, via non-emergency event report 41128 that leak path detection indications had been identified in two reactor pressure vessel head control rod drive mechanism nozzle penetrations at Palisades. At that time, the probable cause of the identified indications was believed to be primary water stress corrosion cracking (PWSCC). As a result, event report 41128 was made in accordance with 10 CFR 50.72(b)(3)(ii)(A) as a condition that resulted in a principle safety barrier being seriously degraded. Based on a recently completed engineering evaluation that compared the indications found in 2004 to the indications identified in subsequent examinations, it was determined the indications originally discovered in 2004 were embedded welding indications, caused by the original welding process. Since the indications identified in 2004 were not caused by PWSCC, serious degradation of a principle safety barrier did not exist. Consequently, the reporting criterion of 10 CFR 50.72(b)(3)(ii)(A) is not applicable. Therefore, event report 41128 is being retracted. In addition, Palisades Licensee Event Report (LER), 2004-002, 'Leak Path Indications Identified in Reactor Pressure Vessel Head Nozzle Penetrations,' is being cancelled. The licensee has notified the NRC Resident Inspector. Notified R3DO (Peterson).