Event Notification Report for June 08, 2016

UNANALYZED CONDITION THAT COULD POTENTIALLY DEGRADE PLANT SAFETY

"At 1526 Eastern Daylight Time on 6/8/2016, a determination was made involving the potential impact of a tornado on the Emergency Diesel Generators (EDGs). The EDGs are required to be operable to provide power to ensure that acceptable fuel design limits, reactor coolant system pressure boundary limits, and containment integrity are not exceeded during abnormal transients. Further, the EDGs are designed with a crankcase pressure trip (setpoint = 1 inch water), which is bypassed during an emergency start. Engineering has determined that a tornado could potentially cause actuation of the crankcase pressure trip due to a low barometric condition. If an emergency start signal has NOT previously occurred, then during a tornado, actuation of the crankcase pressure trip would energize the shutdown relay causing an EDG lockout condition. The EDG lockout condition prevents subsequent EDG starts (normal or emergency) until operators manually reset the lockout condition locally at the EDG. This condition could potentially affect all four EDGs simultaneously.

"The EDGs are operable but degraded. All EDGs have successfully passed their required surveillances within the appropriate frequency. No severe weather warnings or watches are forecast in the local areas, which could challenge the crankcase pressure trip.

"This condition places both units in an unanalyzed condition that potentially significantly degrades plant safety, 10 CFR 50.72 (b)(3)(ii)(B).

"A compensatory measure has been established, that upon notification of a Tornado Warning, the EDGs would be 'emergency started' and run during the time the Tornado Warning was in effect. This action bypasses the crankcase pressure trip function and allows the EDGs to perform their required safety function.

"The NRC Senior Resident Inspector has been notified."

UNANALYZED CONDITION THAT COULD POTENTIALLY DEGRADE PLANT SAFETY

"At 1526 Eastern Daylight Time on 6/8/2016, a determination was made involving the potential impact of a tornado on the Emergency Diesel Generators (EDGs). The EDGs are required to be operable to provide power to ensure that acceptable fuel design limits, reactor coolant system pressure boundary limits, and containment integrity are not exceeded during abnormal transients. Further, the EDGs are designed with a crankcase pressure trip (setpoint = 1 inch water), which is bypassed during an emergency start. Engineering has determined that a tornado could potentially cause actuation of the crankcase pressure trip due to a low barometric condition. If an emergency start signal has NOT previously occurred, then during a tornado, actuation of the crankcase pressure trip would energize the shutdown relay causing an EDG lockout condition. The EDG lockout condition prevents subsequent EDG starts (normal or emergency) until operators manually reset the lockout condition locally at the EDG. This condition could potentially affect all four EDGs simultaneously.

"The EDGs are operable but degraded. All EDGs have successfully passed their required surveillances within the appropriate frequency. No severe weather warnings or watches are forecast in the local areas, which could challenge the crankcase pressure trip.

"This condition places both units in an unanalyzed condition that potentially significantly degrades plant safety, 10 CFR 50.72 (b)(3)(ii)(B).

"A compensatory measure has been established, that upon notification of a Tornado Warning, the EDGs would be 'emergency started' and run during the time the Tornado Warning was in effect. This action bypasses the crankcase pressure trip function and allows the EDGs to perform their required safety function.

"The NRC Senior Resident Inspector has been notified."

HIGH PRESSURE COOLANT INJECTION INOPERABLE

"At 0800 CDT on 6/8/2016, 3-SR-3.5.1.7, 'HPCI [High Pressure Coolant Injection] Main and Booster Pump Set Developed Head and Flow Rate Test at Rated Reactor Pressure' periodic surveillance was being performed. As part of the surveillance procedure, HPCI was declared inoperable per Technical Specification (TS) Limiting Condition for Operation (LCO) 3.5.1 Emergency Core Cooling Systems (ECCS) - Operating, Condition C at 0925. At 1037, the HPCI turbine was started and a turbine trip alarm was received as well as large swings observed on the suction pressure indicator and slow turbine response. The control room operator then manually tripped the HPCI turbine due to the abnormal indications received.

"HPCl is a single train safety system and this notification is being made in accordance with 10 CFR 50.72 (b)(3)(v)(D).

"The NRC Resident Inspector has been notified."

PART-21 REPORT - NONCONFORMANCE ON STRUTHERS-DUNN RELAY FOR PSEG NUCLEAR LLC

"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).

DISCOVERY OF UNISOLABLE REACTOR PRESSURE BOUNDARY LEAKAGE

"Susquehanna Unit 1 identified RPV [reactor pressure vessel] pressure boundary leakage from [local power range monitor] LPRM 24-09 housing above the flange during an under vessel leak inspection on 06/08/2016 at 0226 EDT. The leakage point is a through wall indication on the ASME Class 1 LPRM stub tube. The leakage is not isolable from the reactor vessel. The reactor was in Mode 4 at the time of discovery.

"This event is being reported as a degraded condition pursuant to 10CFR50.72(b)(3)(ii)(A)."

A repair plan is being formulated.

The licensee has notified the NRC Resident Inspector.