RA23-025, Post Accident Monitoring Report

Post Accident Monitoring Report

ML23097A081
Person / Time
Site:	LaSalle
Issue date:	04/07/2023
From:	Van Fleet J Constellation Energy Generation
To:	Office of Nuclear Reactor Regulation, NRC/RGN-III, Document Control Desk
References
RA23-025
Download: ML23097A081 (1)

Text

LaSalle County Station Constellation. 2601 North 21 st Road Marseilles. IL 61341 815-415-2000 Telephone RA23-025 April 7, 2023 U.S. Nuclear Regulatory Commission Attention: NRC Region Ill Administrator 2443 Warrenville Road, Suite 210 Lisle, IL 60532-4352 LaSalle County Station, Unit 2 Renewed Facility Operating License No. NPF-18 NRC Docket Nos. 50-374

Subject:

Post Accident Monitoring Report The attached report is submitted in accordance with LaSalle County Station, Unit 2 Technical Specifications (TS) 3.3.3.1, "Post Accident Monitoring (PAM) Instrumentation," and TS 5.6.6, "Post Accident Monitoring (PAM) Instrumentation Report." The report is required due to the inoperability of one testable check valve position indication for a period greater than the 30 day restoration time. Accordingly, this report is due on April 23, 2023.

There are no regulatory commitments contained in this letter. Should you have any questions concerning this letter, please contact Mr. Dan Mearhoff, Regulatory Assurance Manager, at (815) 415-2800.

Respectfully, Johttl7:"<fkr Acting Site Vice President LaSalle County Station

Enclosure:

LaSalle Unit 2 Post Accident Monitoring Report cc: Regional Administrator - NRC Region Ill NRC Senior Resident Inspector - LaSalle County Station

RA23-025 U.S. Nuclear Regulatory Commission LaSalle Unit 2 Post Accident Monitoring Report This report is submitted for LaSalle County Station, Unit 2 in accordance with Technical Specifications {TS) 5.6.6, "Post Accident Monitoring (PAM) Instrumentation Report."

Additionally, TS 3.3.3.1, "Post Accident Monitoring (PAM) Instrumentation," requires two channels of Penetration Flow Path Primary Containment Isolation Valve (PCIV) position indication to be operable during plant operations in Modes 1 and 2.

On March 10, 2023, the position indication for one feedwater line outboard testable check valve was declared inoperable and TS 3.3.3.1, Condition A was entered, which requires restoration of the channel to operable status in 30 days. If TS 3.3.3.1, Condition A is not satisfied within 30 days, then TS 3.3.3.1, Condition Bis entered. Constellation Energy Generation, LLC has determined that the position indication cannot be restored within 30 days; therefore, TS 3.3.3.1, Condition B requires immediate initiation of action in accordance with TS 5.6.6 to submit a written report within 14 days outlining the preplanned alternate method of monitoring, the cause of the inoperability and the plans/schedule for restoring the instrument channel of the function to operable status.

Description of Issue On March 10, 2023, the light indication for the Unit 2 'A' feedwater line outboard testable check valve 2B21-F032A at Main Control Room (MCR) panel 2H13-P601 indicated dual position, while the valve's expected position was full open while at full-power conditions.

The check valve has passed its leak rate tests and checks as required for a PCIV.

However, the valve did not pass its channel check for position indication. Therefore, the valve was declared inoperable for position indication in accordance with PAM TS 3.3.3.1, which requires the valve's position indication to be restored within 30 days.

Feedwater header flows matched, indicating the 2B21-F032A was full open as expected, and therefore its PCIV function is not impacted. Shift operations verified the feed flow by trending the plant process computer (PPC) points for feedwater 'A' and 'B' header flow, with no discrepancies noted. Both loops trended together within tolerance.

Preplanned Alternate Method of Monitoring The alternative method for monitoring the post-accident position of valve 2B21-F032A is the PPC Primary Containment Isolation System (PCIS) screen and analog PPC points 8713 and B714 for Unit 2 A and B feedwater check valve flows, respectively.

Cause of the Inoperable Condition The cause of valve 2B21-F032A position indication malfunction is the limit switches, which require adjustment. Based on the flow indications observed, the valve remains fully functional. However, in order to perform the required surveillances for the closed indication of valve 2821-F032A, the system is required to have no system flow. Further troubleshooting and repair of the limit switches are precluded while the plant is operating in Mode 1 with the feedwater system in service.

Plans and Schedule for Restoration The repair of the limit switches is scheduled for the first opportunity, in accordance with the station work control process, no later than the upcoming Unit 2 refueling outage L2R20 scheduled for February 2025.

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