05000352/LER-2021-001, HPCI Inoperable Due to Remote Shutdown Panel Switch Failure
| ML21326A008 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 11/22/2021 |
| From: | Sturniolo F Exelon Generation Co LLC |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LG-21-110 LER 2021-001-00 | |
| Download: ML21326A008 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(v), Loss of Safety Function |
| 3522021001R00 - NRC Website | |
text
10 CFR 50.73 LG-21-110 November 22, 2021 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 2021-001-00 Unit 1 HPCI Inoperable Due to Remote Shutdown Panel Switch Failure 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 Laura Lynch at (610) 718-3400.
Respectfully, Frank Sturniolo Vice President - Limerick Generating Station Exelon Generation Company, LLC cc: Administrator Region I, USNRC USNRC Senior Resident Inspector, Limerick Generating Station Digitally signed by Sturniolo, Frank Date: 2021.11.19 09:28:28 -05'00' Exelon Generation
Abstract
Limerick Generating Station Unit 1 352 3
Unit 1 HPCI Inoperable Due to Remote Shutdown Panel Switch Failure 09 23 21 2021 001 00 11 22 21 OPCON 1 100
Laura A. Lynch 610-718-3400 B
BJ HS G223 Yes
During the testing of the High Pressure Coolant Injection (HPCI) System, the HPCI pump failed to obtain the Technical Specification required pressure and flow as a result of high contact resistance in the HPCI Emergency Shutdown Switch. The high resistance was attributed to mechanical switch degradation that was introduced by cycling the switch during the logic system functional Surveillance Test, which was completed 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and 32 minutes prior to the HPCI Pump Valve and Flow Surveillance Test. The switch was replaced, and testing is being developed to verify the switch is functioning after the switch is operated. This event is being reported because it resulted in an unplanned inoperability of a single train safety system that could have prevented fulfillment of a safety function. An eight (8) hour ENS notification was completed on September 23, 2021 at 18:46 hours.
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- 3. LER NUMBER YEAR SEQUENTIAL NUMBER REV NO.
Corrective Actions Planned The Unit 2 HPCI Emergency Shutdown Switch will be proactively replaced during the next scheduled System Outage.
Testing is being developed to verify the HPCI Emergency Shutdown Switch is operable after the completion of the HPCI Logic System Functional Test.
Previous Similar Occurrences There have not been any similar occurrences of this switch failing at Limerick.
Component Data:
System: BJ High Pressure Coolant Injection Component: HS - Handswitch Manufacturer: G223 Grayhill Inc 3
3 Limerick Generating Station Unit 1 352 2021 001 00
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