05000296/LER-2022-003, Pressure Boundary Leak on Residual Heat Removal System Low Pressure Coolant Injection Test Line
| ML23031A357 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 01/31/2023 |
| From: | Sivaraman M Tennessee Valley Authority |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| LER 2022-003-00 | |
| Download: ML23031A357 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded |
| 2962022003R00 - NRC Website | |
text
Post Office Box 2000, Decatur, Alabama 35609-2000 January 31, 2023 10 CFR 50.73 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Browns Ferry Nuclear Plant, Unit 3 Renewed Facility Operating License No. DPR-68 NRC Docket No. 50-296
Subject:
Licensee Event Report 50-296/2022-003-00
Reference:
Non-Emergency Event Notification 56257 - Degraded Condition Discovered on Shutdown Cooling Test Line The enclosed Licensee Event Report provides details of a pressure boundary leak on Browns Ferry Nuclear Plant, Unit 3. The Tennessee Valley Authority is submitting this report in accordance with Title 10 of the Code of Federal Regulations (10 CFR) 50.73(a)(2)(i)(B), as any operation or condition which was prohibited by the plants Technical Specifications; and 10 CFR 50.73(a)(2)(ii)(A), as any event or condition that resulted in the condition of the nuclear power plant, including its principal safety barriers, being seriously degraded.
There will be a supplement to this Licensee Event Report to provide additional time to complete the root cause evaluation.
There are no new regulatory commitments contained in this letter. Should you have any questions concerning this submittal, please contact Christopher L. Vaughn, Nuclear Site Licensing Manager, at (256) 729-2636.
Respectfully, Manu Sivaraman Site Vice President Enclosure: Licensee Event Report 50-296/2022-003 Pressure Boundary Leak on Residual Heat Removal System Low Pressure Coolant Injection Test Line
U.S. Nuclear Regulatory Commission Page 2 January 31, 2023 cc (w/ Enclosure):
NRC Regional Administrator - Region II NRC Senior Resident Inspector - Browns Ferry Nuclear Plant NRC Project Manager - Browns Ferry Nuclear Plant
ENCLOSURE Browns Ferry Nuclear Plant Unit 3 Licensee Event Report 50-296/2022-003-00 Pressure Boundary Leak on Residual Heat Removal System Low Pressure Coolant Injection Test Line See Enclosed
Abstract
On December 2, 2022, at 2330 Central Standard Time (CST), during a drywell entry for leak identification, BFN Engineering personnel discovered a through-wall piping leak on a test line between the two Residual Heat Removal Shutdown Cooling test line isolation valves. On December 3, 2022, at 1000, it was determined that this test line was classified as American Society of Mechanical Engineers Code Class 1 piping and constitutes part of the BFN, Unit 3 Reactor Coolant System pressure boundary. Operations personnel maintained BFN, Unit 3 in Mode 4 or 5 until the leak was repaired. On December 3, 2022, at 1205 CST, eight-hour Event Notification 56257 was made to the NRC. The test line was cut and capped pending permanent repairs.
There will be a supplement to this Licensee Event Report to provide additional time to complete the root cause evaluation.
VII. Previous Similar Events at the Same Site
On January 15, 2022, at 2320 CST, during a drywell entry for leak identification, BFN Engineering personnel discovered a through-wall piping leak on a test line upstream of the RHR and SDC test shut-off valve. This test line is classified as ASME Code Class 1 piping and constitutes part of the BFN, Unit 1 RCS pressure boundary.
The root cause of this event was small bore piping which was not specifically analyzed for fatigue failure vulnerability due to operational or resonance vibration. The corrective action for this event is to implement Engineering Change Packages for all small bore piping with vulnerability to fatigue failure due to exceeding the endurance limit due to operational vibration.
This event was reported to the NRC under Licensee Event Report 50-259/2022-001 Pressure Boundary Leak on Residual Heat Removal System Low Pressure Coolant Injection Test Line.
VIII. Additional Information
There is no additional information.
IX.
Commitments
There are no new commitments.