05000259/LER-2023-001-01, High Pressure Coolant Injection System Inoperable Due to a Torn Valve Diaphragm
| ML23164A134 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  (DPR-033) |
| Issue date: | 06/13/2023 |
| From: | Sivaraman M Tennessee Valley Authority |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| LER 2023-001-01 | |
| Download: ML23164A134 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(v), Loss of Safety Function |
| 2592023001R01 - NRC Website | |
text
Post Office Box 2000, Decatur, Alabama 35609-2000 June 13, 2023 10 CFR 50.73 10 CFR 50.4(a)
ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Browns Ferry Nuclear Plant, Unit 1 Renewed Facility Operating License No. DPR-33 NRC Docket No. 50-259
Subject:
Licensee Event Report 50-259/2023-001 High Pressure Coolant Injection System Inoperable Due to a Torn Valve Diaphragm
Reference:
- 1.
Non-Emergency Event Notification 56321 - High Pressure Coolant Injection Inoperable
- 2.
TVA letter to NRC, Licensee Event Report 50-259/2023-001 High Pressure Coolant Injection System Inoperable Due to a Torn Valve Diaphragm, dated March 27, 2023 (ML23086C092)
The enclosed Licensee Event Report provides details of a failed diaphragm which resulted in the inoperability of the High Pressure Coolant Injection system. The Tennessee Valley Authority (TVA) is submitting this report in accordance with Title 10 of the Code of Federal Regulations (10 CFR) 50.73(a)(2)(v)(D), as any event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident. As noted in the referenced letter, TVA planned to supplement this LER to provide additional time to complete the root cause evaluation.
Accordingly, enclosed is a supplement to the subject LER (i.e., LER 50-259/2023-001-01),
which provides additional detail into the causal factors of the event and includes additional corrective actions to prevent recurrence.
1\14 TENNESSEE VALLEY AUTHORITY
U.S. Nuclear Regulatory Commission Page 2 June 13, 2023
There are no new regulatory commitments contained in this letter. Should you have any questions concerning this submittal, please contact Chris L. Vaughn, Site Licensing Manager, at (256) 729-2636.
Respectfully, Manu Sivaraman Site Vice President
Enclosure:
Licensee Event Report 50-259/2023-001 High Pressure Coolant Injection System Inoperable Due to a Torn Valve Diaphragm cc (w/ Enclosure):
NRC Regional Administrator - Region II NRC Senior Resident Inspector - Browns Ferry Nuclear Plant NRC Project Manager - Browns Ferry Nuclear Plant
Abstract
On January 24, 2023 at 0121 CST, the Browns Ferry Nuclear Plant, Unit 1, High Pressure Coolant Injection (HPCI) was declared inoperable because the normally-open HPCI Steam Line Condensate Outboard Drain Valve failed closed, apparently due to a failed diaphragm. On January 24, 2023, at 0743 CST, eight-hour Event Notification 56321 was made to the NRC.
The Tennessee Valley Authority (TVA) is submitting this report in accordance with Title 10 of the Code of Federal Regulations (10 CFR) 50.73(a)(2)(v)(D), as any event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident.
The diaphragm prematurely failed due to a part manufacturing issue, which led to the local delamination between the fabric and the ethylene propylene diene monomer (EPDM) material, in conjunction with a lack of complete reinforcement fabric coverage at the tear site. The failed diaphragm was replaced. TVA will proactively replace the diaphragms on Browns Ferry Nuclear Plant Units 2 and 3. HPCI Steam Line Condensate Outboard Drain Valve diaphragms will be reclassified and reprocured as QA 1 components, and any existing QA 3 diaphragms will be reclassified as obsolete.
r"'
f
\:.... :;
I I
~
I I
I I
I I I I
I I
I I
I I
I I I
I I
I I
~
ID I
I Page 6 of 6
VIII. Additional Information
There is no additional information.
IX.
Commitments
There are no new commitments.