This letter serves as an interim report in accordance with
10 CFR 21.21 pertaining to a potential deviation associated with Struthers-Dunn relays P/N B255XCXPFHSC125V supplied to
PSEG Nuclear
LLC. Based upon information obtained from
PSEG, a defect may exist with the reset coil of the Struthers-Dunn relay listed above. Preliminary observations indicate the reset coil had shorted (opened) during operation, and that no other sub-components of the relay are believed to be associated with this failure.
PSEG is aware of Curtiss-Wright's investigation into this failure.
Evaluation of reportability in accordance with 10 CFR Part 21 is not able to be completed within the 60-day evaluation period due to the need for additional time to collect and evaluate the necessary information. It is currently expected that the evaluation of this defect will be completed by July 22, 2016.
POC: Timothy Franchuk
Director, Quality Assurance
4600 East Tech Drive
Cincinnati, Ohio 45245
(513) 528-7900
The licensee indicated that the current list of affected plants are being evaluated.
- * * UPDATE ON 07/08/16 AT 1511 EDT FROM MARGIE HOVER TO BETHANY CECERE * * *
The following is excerpted from the submitted report:
Struthers-Dunn Relay P/N: B255XCXP125V. Note that the original interim report identified the part number as B255XCXPFHSC125V, which contains designators 'FHSC', which are an internal Curtiss-Wright numbering scheme.
The following facilities were supplied the components:
Salem Nuclear Generating Station/Hope Creek Generating Station
Total Quantity: 104
Wolf Creek Generating Station
Total Quantity: 10
Evaluation: Findings as a result of the Curtiss-Wright Failure Analysis indicated that the reset coil failure was linked to the magnet wire insulation, the coil winding process, and the attachment of the coil leads to the magnet wire
Corrective Action: Struthers-Dunn has revised their reset coil assembly procedure such that the reset coil receives two wraps of insulation tape prior to laying the magnet wire terminations which are then soldered to the relay leads which connect to the pins at the base of the relay. Based on testing by Struthers-Dunn this two wrap process greatly increases dielectric strength which should eliminate the failure modes identified. Affected relays were returned to Struthers-Dunn to have the reset coil replaced using the revised reset coil assembly method. After the coils have been replaced they are sent to Curtiss-Wright Nuclear Division to be re-dedicated prior to being returned to the end user.
Notified the R1DO (Bower), R4DO (Drake), and Part 21 Group (via email).