05000352/LER-2022-001, Regarding HPCI Inoperable Due to Inadvertent Isolation Signal
| ML22347A286 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 12/13/2022 |
| From: | Gillin M Constellation Energy Generation |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| LG-22-120 LER 2022-001-00 | |
| Download: ML22347A286 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(v), Loss of Safety Function |
| 3522022001R00 - NRC Website | |
text
Constellation 10 CFR 50.73 LG-22-120 December 13, 2022 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Limerick Generating Station, Unit 1 Renewed Facility Operating License No. NPF-39 NRC Docket No. 50-352 Subject: LER 2022-001-00 Unit 1 HPCI Inoperable Due to Inadvertent Isolation Signal In accordance with the requirements of 10 CFR 50.73(a)(2)(v)(D), Limerick Generating Station hereby submits the enclosed Licensee Event Report.
There are no commitments contained in this letter.
If you have any questions, please contact Jordan Rajan at (610) 718-2513.
Respectfully, Michael Gillin Vice President - Limerick Generating Station Constellation Generation Company, LLC cc: Administrator Region I, USNRC USNRC Senior Resident Inspector, Limerick Generating Station
Abstract
Limerick Generating Station Unit 1 352 3
Unit 1 HPCI Inoperable Due to Inadvertent Isolation Signal 10 14 22 2022 001 00 12 13 22 OPCON 1 100
Jordan Rajan 610-718-2513 B
BJ CON I215 Yes
On October 14, 2022, during planned testing of the High Pressure Coolant Injection (HPCI) System, a spurious HPCI Division 2 isolation occurred due to a fault in an electrical connector associated with the HPCI Division 2 isolation reset circuit. The affected electrical connector carries signals for the control circuits of the outboard HPCI Turbine Exhaust Line Vacuum Breaker isolation valve and HPCI Test Line Flush isolation valve and the HPCI Division 2 isolation reset circuit. Closing the outboard HPCI Turbine Exhaust Line Vacuum Breaker isolation valve energized degraded pins within the electrical connector resulting in a fault that initiated the HPCI Division 2 isolation signal. The defective electrical connector was removed, and the affected cable spliced in accordance with an approved design change. This event is being reported as a condition that, at the time of discovery, could have prevented the fulfillment of the safety function of a system needed to mitigate the consequences of an accident. An eight (8) hour ENS notification was completed on October 14, 2022, at 18:03 hours.
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Safety Consequences
There were no actual safety consequences associated with this event. The potential safety consequences of this event were minimal. The HPCI System was removed from service in accordance with Technical Specifications prior to the isolation. The Reactor Core Isolation Cooling (RCIC) System, Automatic Depressurization System (ADS), Residual Heat Removal (RHR) System, and Core Spray (CS) System remained operable during the period that HPCI was inoperable.
Corrective Actions Completed The degraded electrical connector was removed, and the affected cable spliced in accordance with an approved design change.
Corrective Actions Planned Evaluate the need to inspect a representative sample of similar electrical connectors in the Auxiliary Equipment Room cabinets.
Previous Similar Occurrences There have been two recent similar events at Limerick involving degraded electrical connectors. Both events involved electrical connectors that affected motor operated valve control circuits for RCIC System valves. In January 2016, a Unit 2 RCIC Pump Minimum Flow Bypass Valve exhibited erratic performance during a RCIC pump surveillance test. The affected electrical connector was inspected, and several pins were cleaned to restore proper operation of the circuit. In November 2019, when cycling the RCIC Steam Line Warm-up Line isolation valve for in-service testing, a Unit 1 Division 1 Safeguard Battery Ground alarm was received. Two shorted conductors in the affected electrical connector were spared and replaced with two good spare conductors to restore the circuits to the as-designed configuration Component Data System: BJ High Pressure Coolant Injection Component: CON (Connector)
Manufacturer: I215 (Cannon ITT) 3 3
Limerick Generating Station Unit 1 352 2022 001 00
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