ML24114A322

Supplement to License Amendment Request to Revise the Licensing and Design Basis to Incorporate the Replacement of Existing Safety-Related Analog Control Systems with a Single Digital Plant Protection System (PPS) - Pivot to Unit

ML24114A322
Person / Time
Site:	Limerick
Issue date:	04/23/2024
From:	David Helker Constellation Energy Generation
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
Download: ML24114A322 (1)

Text

200 Exelon Way Kennett Square, PA 19348 Constellation www.ConstellationEnergy.com

10 CFR 50.90

April 23, 2024

U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 ATTN: Document Control Desk

Limerick Generating Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-39 and NPF-85 NRC Docket Nos. 50-352 and 50-353

Subject:

Supplement to License Amendment Request to Revise the Licensing and Design Basis to Incorporate the Replacement of Existing Safety-Related Analog Control Systems with a Single Digital Plant Protection System (PPS) -

Pivot to Unit 1 PPS First Installation in 2026

References:

1. Constellation Energy Generation, LLC (CEG) letter to the U.S. Nuclear Regulatory Commission (NRC), "License Amendment Request to Revise the Licensing and Design Basis to Incorporate the Replacement of Existing Safety-Related Analog Control Systems with a Single Digital Plant Protection System (PPS)," dated September 26, 2022 (NRC Agencywide Documents Access and Management System (ADAMS) Accession No. ML22269A569).

2. Constellation Energy Generation, LLC (CEG) letter to the NRC, Supplement to License Amendment Request to Revise the Licensing and Design Basis to Incorporate the Replacement of Existing Safety-Related Analog Control Systems with a Single Digital Plant Protection System (PPS) - Pivot to Unit 2 First Installation, dated May 23, 2023 (ML23143A342).

Per Reference 1 and in accordance with 10 CFR 50.90, Constellation Energy Generation, LLC (CEG) requested amendments to Renewed Facility Operating License Nos. NPF-39 and NPF-85 for Limerick Generating Station (LGS), Units 1 and 2, respectively. The proposed changes would revise the LGS licensing and design basis to incorporate a planned digital modification at LGS (i.e., the LGS Digital Modernization Project DMP)). In Reference 1, CEG communicated plans to implement the LGS DMP during the LGS Unit 1 20th refueling outage (Li1R20) and LGS Unit 2 18th refueling outage (Li2R18), scheduled in April 2024 and April 2025, respectively.

Supplement to DMP License Amendment Request-PPS First Installation in 2026 Limerick Digital Modernization Project Docket Nos. 50-352 and 50- 353 April 23, 2024 Page 2

Per Reference 2, CEG notified NRC that the final design activities for the Plant Protection System (PPS) had been delayed due to additional design refinement iterations with the system Original Equipment Manufacturer. CEG h ad concluded that it was no longer possible to have the design completed and equipment ready in time to support the Unit 1 installation during the April 2024 Refueling Outage. Therefore, CEG pivoted the final design and project activities to support the first installation of the PPS on Unit 2 during its planned April 2025 Refueling Outage.

After a careful review of the current final design and PPS equipment fabrication schedules, CEG has concluded that the current effort will not support a PPS installation during the Unit 2 Refueling Outage in April 2025. The reason for the delay is due to identification of additional new design considerations/issues that had to be addressed/resolved, and current final design and manufacturing schedules that do not meet the CEG internal 2025 Refueling Outage readiness requirements for installation. Accordingly, the Unit 1 first PPS installation is now planned for the LGS Unit 1 21st Refueling Outage (Li1R21) in April 20 26, and second installation PPS is planned for the LGS Unit 2 19th Refueling Outage (Li2R19) in April 2027.

This supplemental letter contains no regulatory commitments.

In accordance with 10 CFR 50.91, "Notice for public comment; State consultation," paragraph (b), CEG is notifying the Commonwealth of Pennsylvania of this LAR supplemental letter by transmitting a copy of this letter to the designated State Official.

If you have any questions regarding this submittal, please contact Frank Mascitelli at Frank.Mascitelli@constellation.com.

I declare under penalty of perjury that the foregoing is true and correct. Executed on this 23nd day of April 2024.

Respectfully,

David P. Helker Sr. Manager - Licensing Constellation Energy Generation, LLC

cc: USNRC Region I, Regional Administrator USNRC Project Manager, LGS "

USNRC Senior Resident Inspector, LGS "

Director, Bureau of Radiation Protection - Pennsylvania Department "

of Environmental Protection