05000259/LER-2023-003, Standby Liquid Control Inoperable Due to Demineralized Water In-Leakage

Standby Liquid Control Inoperable Due to Demineralized Water In-Leakage

ML24029A241
Person / Time
Site:	Browns Ferry
Issue date:	01/29/2024
From:	Sivaraman M Tennessee Valley Authority
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
LER 2023-003-00
Download: ML24029A241 (1)

LER-2023-003, Standby Liquid Control Inoperable Due to Demineralized Water In-Leakage

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(v), Loss of Safety Function
2592023003R00 - NRC Website

text

Post Office Box 2000, Decatur, Alabama 35609-2000 January 29, 2024 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 50-259/2023-003 Standby Liquid Control Inoperable due to Demineralized Water In-leakage The enclosed Licensee Event Report provides details of an inoperability of the Standby Liquid Control 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)(C) &

(D), as any event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material; or mitigate the consequences of an accident.

There are no new regulatory commitments contained in this letter. Should you have any questions concerning this submittal, please contact David Renn, Site Licensing Manager, at (256) 729-2636.

Respectfully, Manu Sivaraman BFN Site Vice President Enclosure:

Licensee Event Report 50-259/2023-003 Standby Liquid Control Inoperable due to Demineralized Water In-leakage cc (w/ Enclosure):

NRC Regional Administrator - Region II NRC Senior Resident Inspector - Browns Ferry Nuclear Plant NRC Project Manager - Browns Ferry Nuclear Plant M

Si

Abstract

A past operability evaluation determined that for a period of time from January 18 to January 19, 2023, the Standby Liquid Control (SLC) system tank sodium pentaborate (SPB) concentration dropped below the requirements of Technical Specification (TS) Surveillance Requirement 3.1.7.3 which requires the SPB solution to be greater than or equal to 8.0% by weight. The cause of this event was leakage past valve 1-SHV-002-1208, SLC Demin Water Supply Shutoff Valve, that allowed demineralized water to dilute the SPB solution in the SLC tank.

The past operability evaluation performed by engineering concluded that although SPB concentration dropped below the TS minimum requirements, sufficient SPB solution was available to provide the required pH buffering function; therefore, the safety function of the SLC system was maintained.

An engineering change to physically separate the SLC tank from the demineralized water system has been implemented to prevent leakage into the SLC tank.

Page 7 of 7 IX.

Commitments There are no new commitments.

Energy Industry Identification System (EIIS) codes are identified in the text as [XX].