ML25251A214

License Amendment Request Supplement for Implementation of Digital Modernization Project – Correction of Revision Numbers and Revised Proposed License Condition

ML25251A214
Person / Time
Site:	Limerick
Issue date:	09/08/2025
From:	Para W Constellation Energy Generation
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
Download: ML25251A214 (1)

Text

200 Energy Way Kennett Square, PA 19348 www.ConstellationEnergy.com 10 CFR 50.90 September 8, 2025 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:

License Amendment Request Supplement for Implementation of Digital Modernization Project - Correction of Revision Numbers and Revised Proposed License Condition

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. ML22269A5690)

2. CEG letter to the NRC, "Resubmittal of 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) -To Address Proprietary Issues with DOE INL HFE Reports 2s," dated September 12, 2023 (ADAMS Accession No. ML23255A095)

3. CEG letter to the NRC, Proposed License Condition - Qualification of Components - Limerick Generating Station Digital Plant Protection System, dated February 21, 2025 (ADAMS Accession No. ML25055A156)

4. CEG letter to the NRC, "Response to Requests for Additional Information

- Equipment Qualification of Components - Limerick Generating Station Digital Plant Protection System" dated July 10, 2025 (ADAMS Accession No. ML25191A224)

LGS DMP LAR Supplement NRC Docket Nos. 50-352 and 50-353 September 8, 2025 Page 2 of 4 In Reference 1 Constellation Energy Generation, LLC (CEG) requested a License Amendment Request (LAR) to facilitate replacement of the Limerick Generating Station, Units 1 and 2 (LGS) existing safety-related analog control systems with a single digital Plant Protection System (PPS) (i.e., the Digital Modernization Project - DMP). In Reference 2, CEG submitted a LAR supplement that replaced in its entirety the original LAR in order to address issues associated with proprietary/non-proprietary information previously submitted.

In Reference 3, CEG transmitted a proposed License Condition (LC) for LGS Unit 1 and Unit 2 that would require completion of all required equipment qualification (EQ) tests and analyses of PPS components prior to startup following the first refueling outage during which the LGS PPS is installed (i.e., Attachment 1 to Reference 3). The required EQ tests and analyses were described in Attachment 2. The proposed LC specifically referenced to that letter as the basis for compliance with the proposed LC.

In Reference 4, CEG submitted responses to ten requests for additional information (RAIs)

(i.e., RAI-37 through RAI-46) concerning the completed and planned EQ tests and analyses for the LGS DMP that were provided in Reference 3. The CEG RAI responses provided additional and revised information for the list of required EQ tests and analyses.

In RAI-38, the NRC requested clarification of the revision numbers for four regulatory and guidance references in the Regulatory Evaluation of the LAR (i.e., Attachment 1, Section 4.0). These are listed below:

Regulatory Guide (RG) 1.75, Revision 3, "Physical Independence of Electric Systems," February 2005 (ADAMS Accession No. ML043630448)

Institute of Electrical and Electronics Engineers (IEEE) Standard (Std) 384-1992, "IEEE Standard Criteria for Independence of Class 1E Equipment and Circuits" RG 1.100, Revision 3, "Seismic Qualification of Electric and Mechanical Equipment for Nuclear Power Plants," September 2009 (ADAMS Accession No. ML091320468)

RG 1.180, Revision 1, "Guidelines for Evaluating Electromagnetic and Radio-Frequency Interference in Safety-Related Instrumentation and Control Systems,"

October 2003 (ADAMS Accession No. ML032740277)

As part of the response to RAI-38, CEG performed an extent of condition (EOC) review of the Regulatory Evaluation to validate the revision numbers for all cited regulatory and guidance references. In addition to the four references cited in RAI-38, CEG identified one additional regulatory reference that required revision:

RG 1.97, Revision 5, "Criteria for Accident Monitoring Instrumentation for Nuclear Power Plants," April 2019 (ADAMS Accession No. ML18136A762)

LGS DMP LAR Supplement NRC Docket Nos. 50-352 and 50-353 September 8, 2025 Page 3 of 4 The following list provides the verified revisions of the affected regulatory and guidance documents listed in the Reference 1 LAR and Reference 2 LAR resubmittal, Attachment 1, Section 4.0.

Regulatory Guide (RG) 1.75, Revision 2, "Physical Independence of Electric Systems," September 1978 (ADAMS Accession No. ML003740265).

Institute of Electrical and Electronics Engineers (IEEE) Standard (Std) 384-1981, "IEEE Standard Criteria for Independence of Class 1E Equipment and Circuits" RG 1.100, Revision 2, "Seismic Qualification of Electric and Mechanical Equipment for Nuclear Power Plants," June 1988 (ADAMS Accession No. ML003740293)

RG 1.180, Revision 2, "Guidelines for Evaluating Electromagnetic and Radio-Frequency Interference in Safety-Related Instrumentation and Control Systems,"

December 2019 (ADAMS Accession No. ML19175A044)

RG 1.97, Revision 2, "Instrumentation for Light-Water-Cooled Nuclear Power Plants to Assess Plant and Environs Conditions During and Following an Accident," December 1980 (ADAMS Accession No. ML060750525)

With respect to the proposed LC that CEG submitted in Reference 3 (i.e., Attachment 1), the proposed LC specifically referenced Attachment 2 to that letter as the basis for LC compliance. Specifically, Attachment 2 listed the required EQ tests and analyses of PPS components, both completed and planned. In that this list of components has been revised in the Reference 4 RAI responses, CEG has revised the proposed LC to reference the correct submittal. The proposed LC revisions for LGS Units 1 and 2 are provided in the Attachment to this letter.

CEG has reviewed the information supporting a finding of no significant hazards consideration, and the environmental consideration, which was previously provided to the NRC in the Reference 1 and 2 letters. CEG has concluded that the information provided in this letter does not affect the bases for concluding that the proposed license amendments do not involve a significant hazards consideration under the standards set forth in 10 CFR 50.92. In addition, CEG has concluded that the information in this letter does not affect the bases for concluding that neither an environmental impact statement nor an environmental assessment needs to be prepared in connection with the proposed amendments.

LGS DMP LAR Supplement NRC Docket Nos. 50-352 and 50-353 September 8, 2025 Page 4 of 4 This letter contains no regulatory commitments.

If you have any questions regarding this submittal, then please contact Ms. Ashley Rickey at Ashley.Rickey@constellation.com.

I declare under penalty of perjury that the foregoing is true and correct. Executed on this 8th day of September 2025.

Respectfully, Wendi Para Senior Manager, Licensing Constellation Energy Generation, LLC Attachment Proposed License Conditions (Revised) cc:

USNRC Region I, Regional Administrator USNRC Project Manager, LGS USNRC Senior Resident Inspector, LGS

LGS DMP LAR Supplement - Revised Proposed License Condition Attachment LGS Digital Modernization Project Page 1 of 1 Docket Nos. 50-352 and 50-353 ATTACHMENT Proposed License Conditions (Revised)

Limerick Generating Station, Unit 1 NRC Docket No. 50-352 (26)

Equipment Qualification Testing and Analysis - Plant Protection System Components Prior to startup following the first refueling outage during which the digital instrumentation and control (DI&C) Plant Protection System (PPS) at the Limerick Generating Station, Unit 1 (LGS) is installed, Constellation Energy Generation, LLC (CEG) shall complete seismic, environmental, and electromagnetic capability (EMC) testing and analysis of critical hardware components, as described in CEG letter to the U.S. Nuclear Regulatory Commission (NRC), "Response to Requests for Additional Information - Equipment Qualification of Components - Limerick Generating Station Digital Plant Protection System" dated February 10, 2025 and July 10, 2025,, "Response to RAI-37 and -39 through -41" (ADAMS Accession No. ML25191A224). To satisfy this License Condition, CEG will formally document the successful completion of the required EQ testing and analyses that are described in of the July 10, 2025 submittal.

Limerick Generating Station, Unit 2 NRC Docket No. 50-353 (15)

Equipment Qualification Testing and Analysis - Plant Protection System Components Prior to startup following the first refueling outage during which the digital instrumentation and control (DI&C) Plant Protection System (PPS) at the Limerick Generating Station, Unit 2 (LGS) is installed, Constellation Energy Generation, LLC (CEG) shall complete seismic, environmental, and electromagnetic capability (EMC) testing and analysis of critical hardware components, as described in CEG letter to the U.S. Nuclear Regulatory Commission (NRC), "Response to Requests for Additional Information - Equipment Qualification of Components - Limerick Generating Station Digital Plant Protection System" dated February 10, 2025 and July 10, 2025,, "Response to RAI-37 and -39 through -41" (ADAMS Accession No. ML25191A224). To satisfy this License Condition, CEG will formally document the successful completion of the required EQ testing and analyses that are described in of the July 10, 2025 submittal.