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Event Notification Report for October 25, 2017

U.S. Nuclear Regulatory Commission
Operations Center

EVENT REPORTS FOR
10/24/2017 - 10/25/2017

EVENT NUMBERS
5303753135

Part 21
Event Number: 53037
Rep Org: ENGINE SYSTEMS, INC
Licensee: ENGINE SYSTEMS, INC.
Region: 1
City: ROCKY MOUNT   State: NC
County:
License #:
Agreement: Y
Docket:
NRC Notified By: TOM HORNER
HQ OPS Officer: VINCE KLCO
Notification Date: 10/26/2017
Notification Time: 17:00 [ET]
Event Date: 10/25/2017
Event Time: 00:00 [EDT]
Last Update Date: 10/26/2017
Emergency Class: NON EMERGENCY
10 CFR Section:
21.21(d)(3)(i) - DEFECTS AND NONCOMPLIANCE
Person (Organization):
BRICE BICKETT (R1DO)
ERIC DUNCAN (R3DO)
PART 21/50.55 REACTO (EMAI)
Event Text
PART 21 - SPEED SWITCH ISSUE RESULTS IN EMERGENCY DIESEL GENERATOR FAILURE TO START

The following information was received by facsimile from the vendor:

"Component: Speed switch P/Ns ESl50267C, ESl50267E, ESl50267H, and ESl50267K.

"Summary: Engine Systems Inc. (ESI) began a 10CFR21 evaluation on September 12, 2017 upon notification of a potential issue with speed switch P/N ESl50267K supplied to Hope Creek Nuclear Generating Station. The speed switch had reportedly failed in service which resulted in a failure to start of the emergency diesel generator (EDG). An analysis performed by Exelon Powerlabs determined the failure was due to a shorted capacitor that is installed on the speed switch's relay output contacts to ground. The evaluation was concluded on October 25, 2017 and it was determined that this issue is a reportable defect as defined by 10CFR Part 21. The speed switch output contacts are utilized in the engine's start circuitry and failure to function properly could adversely affect the safety-related operation of the emergency diesel generator set.

"Impact on Operability: If the resistance path to ground were sufficiently low, the ability of the relay output contacts to pick-up and/or drop-out associated components would be compromised. The speed switch relays are used in safety-related EDG start circuitry to control various electrical relays. Failure to properly control any of these components could adversely affect the safety-related operation of the emergency diesel generator.

"Root cause evaluation: The root cause of the failure is a deficiency in the design and selection of the EMC (Electromagnetic compatibility) mitigating components. Consideration was not given for the impact of voltage transients imparted on the capacitors during coil de-energization. For customers without suppression from the inductive kick, the magnitude of voltage transients may be sufficient to damage and ultimately degrade the capacitors to the point of failure."

Affected nuclear plants include Nine Mile Point, Quad Cities, Dresden, Davis Besse and Hope Creek.


Power Reactor
Event Number: 53135
Facility: PRAIRIE ISLAND
Region: 3     State: MN
Unit: [1] [2] []
RX Type: [1] W-2-LP,[2] W-2-LP
NRC Notified By: ALEX THORNBURG
HQ OPS Officer: MARK ABRAMOVITZ
Notification Date: 12/22/2017
Notification Time: 11:09 [ET]
Event Date: 10/25/2017
Event Time: 20:50 [CDT]
Last Update Date: 12/22/2017
Emergency Class: NON EMERGENCY
10 CFR Section:
50.73(a)(1) - INVALID SPECIF SYSTEM ACTUATION
Person (Organization):
BILLY DICKSON (R3DO)
Power Reactor Unit Info
Unit SCRAM Code RX Crit Initial PWR Initial RX Mode Current PWR Current RX Mode
1 N Y 100 Power Operation 100 Power Operation
2 N N 0 Defueled 0 Defueled
Event Text
INVALID ACTUATION OF COOLING WATER SYSTEM

"At 2050 [CDT] on October 25, 2017, during the Unit 2 refueling outage, with no fuel in the Reactor Vessel, control room operators found that Unit 1 Train B Containment Fan Coil Units (FCUs) had swapped from chilled water to cooling water (CL). Construction Electricians were installing a new relay 2Sl-22X when the plunger on adjacent relay 2Sl-23X was bumped, which caused the swap of the Unit 1 Containment Fan Coil Units (CFCUs) from chilled water to cooling water. Relay 2SI-23X is a slave relay that starts 22 Turbine Driven Auxiliary Feed Water Pump, illuminates blue lights on various control switches, closes MV-32159 Loop A/B CLG WTR HDR XOVR MV B, closes chilled water Isolation Valves to Unit 1 Train B, and closes chilled water Isolation Valves to Unit 2 Train B.

"This actuation was as expected. CL is a shared system and, upon a Safety Injection (SI) signal on either unit, the CL header splits into two trains and, as a result, the CL supply is isolated to the chillers that supply chilled water to both units' CFCUs. By design, CL is the safety related source of cooling to the CFCUs.

"22 Turbine Driven Auxiliary Feed Water Pump did not start as the unit was in 'No Mode' with the control switch for the pump in manual. MV-32159 did automatically close per design. Unit 2 Chilled Water was already isolated due to work in progress with the unit in 'No Mode.'

"There was no impact on public health and safety.

"This event is being reported as a 60-day telephone notification in accordance with 10 CFR 50.73(a)(2)(iv)(A) as an invalid actuation of a containment heat removal system (the FCUs were running, but were swapped to their safeguards source due to an invalid actuation of a relay)."

The licensee notified the NRC Resident Inspector.