05000259/LER-2022-002, High Pressure Coolant Injection System Declared Inoperable Due to a Corroded Actuator

High Pressure Coolant Injection System Declared Inoperable Due to a Corroded Actuator

ML22255A227
Person / Time
Site:	Browns Ferry
Issue date:	09/12/2022
From:	Sivaraman M Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LER 2022-002-00
Download: ML22255A227 (8)

LER-2022-002, High Pressure Coolant Injection System Declared Inoperable Due to a Corroded Actuator

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(v), Loss of Safety Function
2592022002R00 - NRC Website

text

Post Office Box 2000, Decatur, Alabama 35609-2000 September 12, 2022 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 50-259/2022-002 High Pressure Coolant Injection System Declared Inoperable Due to a Corroded Actuator The enclosed Licensee Event Report provides the details of the inoperability of the Browns Ferry Nuclear Plant, Unit 1, High Pressure Coolant Injection System due to a corroded actuator.

The Tennessee Valley Authority is submitting this report in accordance with Title 10 of the Code of Federal Regulations 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.

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 Chris L. Vaughn, Site Licensing Manager, at (256) 729-2636.

Respectfully, Manu Sivaraman Site Vice President Enclosure: Licensee Event Report 50-259/2022-002 High Pressure Coolant Injection System Declared Inoperable Due to a Corroded Actuator

U.S. Nuclear Regulatory Commission Page 2 September 12, 2022

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 July 12, 2022, during a routine surveillance test, the Browns Ferry Nuclear Plant (BFN), Unit 1, high pressure coolant injection (HPCI) turbine control (governor) valve did not open as expected. Upon investigation, it was discovered that the electro-governor remote hydraulic actuator (EGR) had internal corrosion, which resulted in binding of the pilot plunger and associated pilot bushing and a subsequent failure to supply a hydraulic open signal to the governor valve.

The resulting inoperability of the single-train HPCI system would have prevented HPCI from fulfilling its safety function to mitigate the consequences of an accident.

The causal analysis and corrective actions will be reported later in a supplement to this LER.

Page 6 of 6 VI.

Corrective Actions

Corrective Actions are being managed by the TVAs corrective action program under Condition Report (CR) 1789217.

A. Immediate Corrective Actions

The EGR and remote servo were promptly replaced.

B. Corrective Actions to Prevent Recurrence or to reduce the probability of similar events occurring in the future The corrective actions will be reported later in a supplement to this LER.

VII. Previous Similar Events at the Same Site

A search of LERs from BFN, Units 1, 2, and 3 over the last five years identified no similar events.

VIII. Additional Information

There is no additional information.

IX.

Commitments

There are no new commitments.