ML24177A151

Post Accident Monitoring Instrumentation Report

ML24177A151
Person / Time
Site:	Peach Bottom
Issue date:	06/24/2024
From:	Stiltner R Constellation Energy Generation
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
CCN 24-32
Download: ML24177A151 (1)

Text

Technical Specification 5.6.6 CCN 24-32 June 24, 2024 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Peach Bottom Atomic Power Station, Unit 2 Subsequent Renewed Facility Operating License Nos. DPR-44 NRC Docket No. 50-277

Subject:

Post Accident Monitoring Instrumentation Report The attached report is submitted in accordance with Peach Bottom Atomic Power 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 inoperability of open position indication for a Main Steam Isolation Valve for a period greater than the 30-day restoration time.

There are no regulatory commitments contained in this letter.

If you have any questions, please contact Wade Scott, Regulatory Assurance Manager, at (717) 456-3047.

Respectfully, Ryan C. Stiltner Plant Manager Peach Bottom Atomic Power Station Constellation Energy Generation, LLC

Attachment:

Peach Bottom Unit 2 Post Accident Monitoring Report cc:

USNRC Regional Administrator, Region I USNRC Senior Resident Inspector, PBAPS USNRC Project Manager, NRR Director, Bureau of Radiation Protection, Pennsylvania Department of Environmental Resources

Stiltner, Ryan C Digitally signed by Stiltner, Ryan C Date: 2024.06.24 10:44:24

-04'00'

Attachment June 24, 2024 Page 1 of 1 Peach Bottom Unit 2 Post Accident Monitoring Report Reason for Report This report is submitted in accordance with Peach Bottom Atomic Power Station Technical Specifications (TS) 3.3.3.1, Post Accident Monitoring (PAM) Instrumentation, and 5.6.6, Post Accident Monitoring (PAM) Instrumentation Report. TS 3.3.3.1 requires two channels of Primary Containment Isolation Valve (PCIV) instrumentation per penetration flow path to be operable during plant operations in Modes 1 and 2. TS LCO 3.3.3.1 Condition A stipulates with one of more functions with one required channel inoperable, restore the required channel to operable status within 30 days or Condition B is entered which requires action in accordance with TS 5.6.6. TS 5.6.6 states that a report shall be submitted within the following 14 days, which outlines the preplanned alternate method of monitoring, the cause of the inoperability, and the plans and schedule for restoring the instrumentation channels of the function to OPERABLE status.

Summary of the PAM Instrument Inoperability On May 12, 2024, it was identified that the valve open indication light for the 2C inboard Main Steam Isolation Valve (MSIV), AO-2-01A-080C, was extinguished. The indication returned on May 15, 2024, with no work performed, and TS 3.3.3.1 Condition B was exited. Subsequently, on May 19, 2024, the light extinguished and TS 3.3.3.1 Condition B was entered again. Alternate indications were used to confirm that the valve had not changed position and this issue was limited to indication only. The issue appears to be isolated to a limit switch that provides position indication and is separate from the limit switches which input to the Reactor Protective System (RPS). The MSIV and associated instrumentation was confirmed to be operable to support its TS 3.3.1.1, RPS Instrumentation, TS 3.3.6.1, Primary Containment Isolation Instrumentation, and TS 3.6.1.3, PCIVs, functions.

Due to the location of the suspect equipment, this issue cannot be repaired online. Since it has been determined that this position indication cannot be repaired within 30 days, this report is being submitted to provide the information required by TS 5.6.6.

Preplanned Alternate Method of Monitoring In accordance with TS 5.6.6, a preplanned alternate method of monitoring was developed. Alternate indications of main steam line flowrate and differential pressure across the MSIV will be used to monitor the position of the valve.

Cause of Inoperability The cause of the failed valve open indication light is associated with the limit switch which provides input to this indication. This has been confirmed by using alternate parameters to ensure the valve has not changed position, as well as confirmatory data from the plant computer. The limit switches which provide input to the RPS are unaffected by this condition.

Plans and Schedule for Restoration Because the location of this valve is inside primary containment and therefore inaccessible at power, a work request has been generated to repair the condition at the next available opportunity (i.e.

forced outage or refueling outage). This will occur no later than the upcoming Unit 2 refueling outage P2R25 scheduled for October 2024.

Ref. Issue Report 4773592

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