ML25191A223

Response to Requests for Additional Information - Equipment Qualification of Components Digital Plant Protection System

ML25191A223
Person / Time
Site:	Limerick
Issue date:	07/10/2025
From:	Para W Constellation Energy Generation
To:	Office of Nuclear Reactor Regulation, Document Control Desk
Shared Package
ML25191A222	List: ML25191A223
References
Download: ML25191A223 (1)

Text

200 Energy Way Kennett Square, PA 19348 www.ConstellationEnergy.com ATTACHMENTS 1 AND 2 TRANSMITTED HEREWITH CONTAINS PROPRIETARY INFORMATION - WITHHOLD UNDER 10 CFR 2.390 ATTACHMENTS 1 AND 2 TRANSMITTED HEREWITH CONTAINS PROPRIETARY INFORMATION - WITHHOLD UNDER 10 CFR 2.390 10 CFR 50.90 July 10, 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:

Response to Requests for Additional Information - Equipment Qualification of Components - Limerick Generating Station Digital Plant Protection System

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. 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 INL HFE Reports," 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).

Response to RAIs - Equipment Qualification of Components Limerick Digital Modernization Project Docket Nos. 50-352 and 50-353 July 10, 2025 Page 2 of 5 ATTACHMENTS 1 AND 2 TRANSMITTED HEREWITH CONTAIN PROPRIETARY INFORMATION - WITHHOLD UNDER 10 CFR 2.390 When separated, the cover letter, Attachment 3, Attachment 4, Attachment 5, and Attachment 6 are decontrolled.

4.

Teleconference on June 9, 2025 between U.S. Nuclear Regulatory Commission (NRC) (Michael Marshall, et al) and Constellation Energy Generation, LLC, (CEG) (Ashley Rickey, et al).

In Reference 1 Constellation Energy Generation, LLC (CEG) requested a License Amendment Request (LAR) to facilitate replacement of the Limerick Generating Station (LGS), Units 1 and 2 existing safety-related analog control systems with a single digital Plant Protection System (PPS). In Reference 2, CEG submitted a LAR supplement that replaced the original LAR in its entirety to address issues associated with proprietary/non-proprietary information.

In both the Reference 1 LAR submittal and Enclosure 1 to the Reference 2 LAR resubmittal, CEG indicated that the LAR was developed and submitted in accordance with the Alternate Review Process (ARP) guidance in NRC Digital Instrumentation and Control (DI&C) Interim Staff Guidance (ISG)-06, Licensing Process.

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). Attachment 2 described the completed and planned EQ tests and analyses of PPS components. This Attachment also listed the applicable PPS components and associated test status in Table 1, Isolation Barrier Fault Testing, and Table 2, LGS PPS Component Equipment Qualification Testing.

During the Reference 4 teleconference, the NRC provided ten requests for additional information (RAIs) (i.e., RAI-37 through RAI-46) concerning the completed and planned EQ tests and analyses described and listed in Reference 3. This letter and six Attachments provide a response to the ten RAIs, as listed below:

to this letter provides a response to RAI-37 and -39 through

-41. These responses include a revised version of the two tables that were originally provided in Reference 3, Attachment 2 (i.e., Table 1, Isolation Barrier Fault Testing, and Table 2, LGS PPS Component Equipment Qualification Testing). Attachment 1 includes information proprietary to WEC.

to this letter provides a response to RAI-38 and -42 through

-46. Attachment 2 includes information proprietary to CEG.

Response to RAIs - Equipment Qualification of Components Limerick Digital Modernization Project Docket Nos. 50-352 and 50-353 July 10, 2025 Page 3 of 5 ATTACHMENTS 1 AND 2 TRANSMITTED HEREWITH CONTAIN PROPRIETARY INFORMATION - WITHHOLD UNDER 10 CFR 2.390 When separated, the cover letter, Attachment 3, Attachment 4, Attachment 5, and Attachment 6 are decontrolled.

to this letter provides a non-proprietary version of Attachment 1.

to this letter provides a non-proprietary version of Attachment 2.

provides an affidavit signed by WEC, the owner of proprietary information in Attachment 1. The affidavit sets forth the basis upon which the information may be withheld from public disclosure by the NRC, and it addresses with specificity the considerations listed in paragraph (b)(4) of 10 CFR 2.390 of the NRCs regulations. WEC requests that the WEC proprietary information contained in be withheld from public disclosure in accordance with 10 CFR 2.390.

Future correspondence with respect to the proprietary aspects of the application for withholding related to WEC proprietary information or the WEC affidavit provided in the applicable attachment should reference this affidavit.

provides an affidavit signed by CEG, the owner of proprietary information in Attachment 2. The affidavit sets forth the basis upon which the information may be withheld from public disclosure by the NRC, and it addresses with specificity the considerations listed in paragraph (b)(4) of 10 CFR 2.390 of the NRCs regulations. CEG requests that the proprietary information contained in be withheld from public disclosure in accordance with 10 CFR 2.390.

Future correspondence with respect to the proprietary aspects of the application for withholding related to CEG proprietary information or the CEG affidavit provided in the applicable attachment should reference this affidavit.

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 RAI response 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.

This letter contains no regulatory commitments.

Response to RAIs - Equipment Qualification of Components Limerick Digital Modernization Project Docket Nos. 50-352 and 50-353 July 10, 2025 Page 4 of 5 ATTACHMENTS 1 AND 2 TRANSMITTED HEREWITH CONTAIN PROPRIETARY INFORMATION - WITHHOLD UNDER 10 CFR 2.390 When separated, the cover letter, Attachment 3, Attachment 4, Attachment 5, and Attachment 6 are decontrolled.

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

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 10th day of July, 2025.

Respectfully, Wendi Para Senior Manager, Licensing Constellation Energy Generation, LLC

Response to RAIs - Equipment Qualification of Components Limerick Digital Modernization Project Docket Nos. 50-352 and 50-353 July 10, 2025 Page 5 of 5 ATTACHMENTS 1 AND 2 TRANSMITTED HEREWITH CONTAIN PROPRIETARY INFORMATION - WITHHOLD UNDER 10 CFR 2.390 When separated, the cover letter, Attachment 3, Attachment 4, Attachment 5, and Attachment 6 are decontrolled.

Response to RAI-37 and -39 through -41 (Proprietary)

Response to RAI-38 and -42 through -46 (Proprietary)

Response to RAI-37 and -39 through -41 (Non-Proprietary)

Response to RAI-38 and -42 through -46 (Non-Proprietary)

WEC Affidavit CAW-25-034 for WEC Proprietary Information in CEG Affidavit, CEG Procured Cable Fiber Optic Cable Equipment Qualification Testing, dated July 8, 2025, for CEG Proprietary Information in Attachment 2 cc:

USNRC Region I, Regional Administrator w/ attachments USNRC Project Manager, LGS USNRC Senior Resident Inspector, LGS Director, Bureau of Radiation Protection - Pennsylvania Department of Environmental Protection

Response to RAI-37 and -39 through -41 (Non-Proprietary)

LGS Digital Modernization Project Page 1 of 6 Docket Nos. 50-352 and 50-353 ATTACHMENTS 1 AND 2 TRANSMITTED HEREWITH CONTAINS PROPRIETARY INFORMATION - WITHHOLD UNDER 10 CFR 2.390 When separated, the cover letter, Attachment 3, Attachment 4,, and Attachment 6 are decontrolled ATTACHMENT 3 Response to RAI-37 and -39 through -41 (Non-Proprietary)

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

RAI-37

The relevant regulatory guidance for Class 1E to non-Class 1E isolation testing is provided in Section 6.3.6 of EPRI TR-107330, as endorsed by Regulatory Guide (RG) 1.209. This guidance is referenced in both the LAR (i.e., the licensee's letters listed in the first paragraph of this document prior to its letter dated February 21, 2025) and the proposed license condition.

However, for Items 34, 36, and 38 in Table 1 of the licensee's proposed license condition, the NRC staff notes ((that fault voltages of 140 VAC/140 VDC)) are used as acceptance criteria. These values do not align with the guidance in RG 1.209 and its endorsed EPRI TR-107330, which specify 600 VAC and 250 VDC for 30 seconds as the acceptance criteria.

Please provide justification or clarification for the use of lower fault voltage values as acceptance criteria for these items.

RESPONSE

((

))

RAI-39

In order for the licensees proposed license condition to be an acceptable substitute for submittal of test summaries describing adequate EQ testing and analysis, the proposed license condition needs to identify all the components the license has not provided type test data or reasonable engineering extrapolation based on test data available to verify that protection system equipment is capable of consistently meeting the performance requirements necessary to fulfill system safety functions.

a) The NRC staff notes that Attachment 3 of the RAI responses submitted on May 3, 2024, identifies several circuits and associated cables that require additional testing or evaluation. However, the NRC staff could not locate these components in the proposed license condition.

Please explain why these components are not included in the licensees proposed license condition.

Response to RAI-37 and -39 through -41 (Non-Proprietary)

LGS Digital Modernization Project Page 2 of 6 Docket Nos. 50-352 and 50-353 ATTACHMENTS 1 AND 2 TRANSMITTED HEREWITH CONTAINS PROPRIETARY INFORMATION - WITHHOLD UNDER 10 CFR 2.390 When separated, the cover letter, Attachment 3, Attachment 4,, and Attachment 6 are decontrolled

RESPONSE

((

))

b) Additionally, Attachment 1 of the same RAI responses lists seven components still requiring electromagnetic compatibility (EMC) testing, two components with pending environmental testing, and three components open for seismic testing. The NRC staff notes that Table 1 of the proposed LC does not provide the current qualification testing status (environmental, seismic, or EMC) for these components.

Please clarify the status of the required qualification testing for these components and explain why the required environmental, seismic, or EMC testing for these components are not included in the licensees proposed license condition.

RESPONSE

((

))

RAI-40

For Items 54 and 55 in Table 2 of the proposed LC, the NRC staff notes that "N/A" (not applicable) is listed for both environmental and seismic qualification testing.

Please provide justification or clarification as to why environmental and seismic qualification testing are not applicable for these two components.

RESPONSE

((

))

Response to RAI-37 and -39 through -41 (Non-Proprietary)

LGS Digital Modernization Project Page 3 of 6 Docket Nos. 50-352 and 50-353 ATTACHMENTS 1 AND 2 TRANSMITTED HEREWITH CONTAINS PROPRIETARY INFORMATION - WITHHOLD UNDER 10 CFR 2.390 When separated, the cover letter, Attachment 3, Attachment 4,, and Attachment 6 are decontrolled

RAI-41

In order for the licensees proposed license condition to be an acceptable substitute for submittal of test summaries describing adequate EQ testing and analysis, the proposed license condition needs to identify all the components the license has not provided type test data or reasonable engineering extrapolation based on test data available to verify that protection system equipment is capable of consistently meeting the performance requirements necessary to fulfill system safety functions.

a) The NRC staff notes that for Item 51 in Table 2 of the proposed license condition, the entry for the component part number is listed as See remarks. However, the NRC staff was unable to locate the corresponding remarks in the licensees proposed license condition.

Please specify the component part number for Item 51 that will be used for the Limerick digital modernization project.

RESPONSE

((

))

b) The NRC staff notes that for Items 3, 35, and 52 in Table 2 of the proposed license condition, no specific part or model numbers are provided for those items.

Please identify the specific or complete part or model numbers for these components that are to be qualified and used for the Limerick digital modernization project.

RESPONSE

((

))

Response to RAI-37 and -39 through -41 (Non-Proprietary)

LGS Digital Modernization Project Page 4 of 4 Docket Nos. 50-352 and 50-353

((

))

ATTACHMENTS 1 AND 2 TRANSMITTED HEREWITH CONTAINS PROPRIETARY INFORMATION - WITHHOLD UNDER 10 CFR 2.390 When separated, the cover letter, Attachment 3, Attachment 4,, and Attachment 6 are decontrolled

Response to RAI-38 and -42 through -46 (Proprietary)

LGS Digital Modernization Project Page 1 of 6 Docket Nos. 50-352 and 50-353 ATTACHMENTS 1 AND 2 TRANSMITTED HEREWITH CONTAINS PROPRIETARY INFORMATION - WITHHOLD UNDER 10 CFR 2.390 When separated, the cover letter, Attachment 3, Attachment 4,, and Attachment 6 are decontrolled ATTACHMENT 4 Response to RAI-38 and -42 through -46 (Non-Proprietary)

Limerick Generating Station, Units 1 and 2 NRC Docket Nos. 50-352 and 50-353 RAI-38, PART a)

The version numbers of some of the documents included in the licensees proposed license condition are inconsistent with version numbers included in the parts of the application submitted prior to February 21, 2025. The NRC staff notes that the following regulatory guides and endorsed IEEE standard are referenced in the LAR:

RG 1.75, Revision 3 IEEE Std. 384-1992 RG 1.100, Revision 3 RG 1.180, Revision 1 Specifically, Section 4.0 of the LAR and Attachment 1 to the letter from Constellation to the U.S. NRC dated May 3, 2024, used the above regulatory guides and standards. In addition, (EQ-QR-433-GLIM, Qualification Summary Report for the Plant Protection System Upgrade for Limerick Units 1 & 2, Rev. 1) in LAR supplement dated November 21, 2023, references RG 1.100, Revision 2. However, the proposed license conditions cite different versions of these documents:

RG 1.75, Revision 2 IEEE Std. 384-1974 RG 1.100, Revision 1 RG 1.180, Revision 2 The versions of the guidance documents listed above are inconsistent between the licensee's proposed license condition and the rest of the licensee's application describing how EQ testing and analysis has been and will be performed.

a) For each of the guidance documents listed above, please explain why the versions included in the proposed license condition are different than the versions describing how the licensee has conducted and plan to conduct EQ testing and analysis in the rest of the licensees application.

CEG RESPONSE TO RAI-38, PART a)

The difference in version numbers for the specified guidance documents was due to administrative oversight during development and internal review of the license amendment request (LAR) and proposed license conditions. CEG has performed an extent of condition (EOC) review of the Regulatory Evaluation in the LAR (i.e. Section 5) to validate the revision numbers for all of the cited regulatory references. In addition to the four references cited above, the EOC review identified one additional regulatory reference with an incorrect

Response to RAI-38 and -42 through -46 (Proprietary)

LGS Digital Modernization Project Page 2 of 6 Docket Nos. 50-352 and 50-353 ATTACHMENTS 1 AND 2 TRANSMITTED HEREWITH CONTAINS PROPRIETARY INFORMATION - WITHHOLD UNDER 10 CFR 2.390 When separated, the cover letter, Attachment 3, Attachment 4,, and Attachment 6 are decontrolled revision number (i.e., RG 1.97). CEG will submit a revised version of the Regulatory Evaluation to correct the revision numbers.

RAI-38, PART b) b)

For each of the guidance documents listed above, please confirm which version of the document listed above will be used in the completion of the EQ testing and analysis of the components included in the licensees proposed license condition.

CEG RESPONSE TO RAI-38, PART b)

The following document versions will be used in the completion of the EQ testing and analysis of the components included in the proposed license condition:

RG 1.75, Revision 2 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 RG 1.180, Revision 2 RAI-38, PART c) c)

For each of the guidance documents listed above, please confirm which version of the guidance document was used in the completion of the EQ testing and analysis results in the EQ summary reports submitted to the NRC staff.

CEG RESPONSE TO RAI-38, PART c)

The following document versions were used in the completion of the EQ testing and analysis results in the EQ summary reports submitted to the NRC staff.

RG 1.75, Revision 2 IEEE Std. 384-1981 RG 1.100, Revision 2 RG 1.180, Revision 2 RAI-42, PARTS a) and b)

The maximum temperature for environmental conditions for the fiber optic cable listed in the licensees proposed license condition is inconsistent with the temperature listed in Constellations letter dated May 3, 2024. The equipment qualification criteria for fiber cable assemblies in Table 2, which the staff understands to be the fiber optic cables located outside of the cabinet, specifies a maximum temperature criterion of (( )) whereas Table 3 and the fiber optic procurement specification NE-381 specifies (( )). The procurement specification contains a table that list calculated normal and maximum plant environmental conditions for Limerick.

Response to RAI-38 and -42 through -46 (Proprietary)

LGS Digital Modernization Project Page 3 of 6 Docket Nos. 50-352 and 50-353 ATTACHMENTS 1 AND 2 TRANSMITTED HEREWITH CONTAINS PROPRIETARY INFORMATION - WITHHOLD UNDER 10 CFR 2.390 When separated, the cover letter, Attachment 3, Attachment 4,, and Attachment 6 are decontrolled a) Please explain why the criteria are different in these two tables.

b) Please confirm which temperature will be used in the environmental acceptance criteria for the fiber optic cable. If the temperature in the acceptance criteria is less than the maximum calculated plant environmental conditions, please justify the use of the lower temperature.

CEG RESPONSE TO RAI-42, PARTS a) and b)

The equipment qualification for fiber cable assemblies in Table 2 is for fiber optic cable used within the PPS cabinet. CEG specified the (( )) criteria for fiber optic cables used within the PPS cabinets to Westinghouse.

The fiber optic cables listed in Table 3 are field cables which are located outside the PPS cabinets. The field cable installation location is limited to the Control Enclosure, specifically the Control Room, Plant Generator Control Center, and Cable Spreading Room. These fiber optical cable locations are in a mild environment, as described below. CEG established the criteria of (( )) for these field cables as a contingency to add additional margin.

Station calculations identify the environmental service condition and the maximum temperature during design basis loss of coolant accident (LOCA)/high energy line break (HELB) and normal operating conditions. The maximum temperature during a LOCA/HELB and normal operating condition in these locations is (( )). While there is a difference in qualification temperatures in Table 2 and 3, both temperatures bound the existing calculated plant environmental conditions.

Both values will be used depending how the cable was purchased. As indicated above, both temperatures bound the calculated maximum temperatures for the installation locations.

RAI-43, PARTS a) and b)

In Specification No. NE-381, the licensee stated that the basis for establishing thermal age conditioning of samples to simulate their qualified life shall be Arrhenius method. While the NRC has accepted the use of the Arrhenius method as a means to simulate thermal aging for qualification, the application and proposed license condition are unclear as to how this method will be applied for thermally aging the fiber optic cables.

a) Please explain how you plan to utilize the Arrhenius method to thermally age condition applicable fiber optic samples to simulate their qualified life. In your response, please explain how you have determined the activation energy for the fiber optic cable.

b) Additionally, if solely relying on the Arrhenius method to thermally age condition applicable fiber optic samples, please discuss how unanticipated degradation which may not be reflected in the results of the accelerated aging process will be accounted for.

Response to RAI-38 and -42 through -46 (Proprietary)

LGS Digital Modernization Project Page 4 of 6 Docket Nos. 50-352 and 50-353 ATTACHMENTS 1 AND 2 TRANSMITTED HEREWITH CONTAINS PROPRIETARY INFORMATION - WITHHOLD UNDER 10 CFR 2.390 When separated, the cover letter, Attachment 3, Attachment 4,, and Attachment 6 are decontrolled CEG RESPONSE TO RAI-43, PARTS a) and b):

Specification NE-381 provides the requirement to use the Arrhenius method for determine if an aging mechanism is significant subsequent to 1) manufacture; 2) while in storage; and 3) and/or in normal and abnormal service environment, such that degradation of the fiber optic cable and or components progressively and appreciably renders the fiber optic cable vulnerable to failure to perform its safety function.

The fiber optic cable installation location is limited to the Control Enclosure, specifically the Control Room, Plant Generator Control Center, and Cable Spreading Room. These locations where the fiber optic cables are being installed are in a mild environment. Station calculations identify the environmental service condition. No significant aging mechanisms have been identified for the Class 1E instrumentation and control equipment that are located in a mild environment. Although the Arrhenius method is described, it is not required for the cable procured in accordance with specification NE-381, based on the installation environment conditions. CEG included the Arrhenius method requirement in NE-381 as a generic contingency, should the need arise due to design changes.

RAI-44

The application is unclear as to how radiation conditioning of the fiber optic cables described in Specification No. NE-381 will be addressed in the qualification plan. An increase in temperature during or after radiation aging can decrease the amount of signal attenuation in fiber optic cables. As such, consensus standards such as the IEEE Std 1682-2023, IEEE Standard for Qualifying Fiber Optic Cables, Connections, and Optical Fiber Splices for Use in Safety Systems in Nuclear Power Generating Stations, recommend that thermal aging be performed prior to radiation aging and the temperature of the radiation aging facility be at or below the end use application, unless otherwise justified. Performing thermal aging after radiation aging may place the optical fiber in a non-conservative condition.

Please describe how this specific aspect related to aging of the fiber optic cables during the qualification process will be performed.

CEG RESPONSE TO RAI-44:

Radiation aging of the fiber optic cables is not required based on the installation location of the cable. The fiber optic cable installation location is limited to the control enclosure at Limerick Generating Station. The cable installation location is limited to the Control Enclosure, specifically the Control Room, Plant Generator Control Center, and Cable Spreading Room. These installation locations for the fiber optic cables are in a mild environment. Station calculations identify the environmental service condition and the maximum dose rate during normal operating conditions and dose during design basis loss of coolant accident (LOCA) / high energy line break (HELB). The dose rate and total ionizing dose (TID) during normal operation and accident conditions in these areas are consistent with a mild environment.

Response to RAI-38 and -42 through -46 (Proprietary)

LGS Digital Modernization Project Page 5 of 6 Docket Nos. 50-352 and 50-353 ATTACHMENTS 1 AND 2 TRANSMITTED HEREWITH CONTAINS PROPRIETARY INFORMATION - WITHHOLD UNDER 10 CFR 2.390 When separated, the cover letter, Attachment 3, Attachment 4,, and Attachment 6 are decontrolled No significant aging mechanisms have been identified for the Class 1E instrumentation and control equipment that are located in a mild environment. Therefore, instead of determining a qualified life, as is done for equipment that may be subjected to a harsh environment, a design life is determined.

IEEE Std 323-2003, IEEE Standard for Qualifying Class 1E Equipment for Nuclear Power Generating Stations, states that as long as periodic surveillance/maintenance testing programs adequately address significant aging mechanisms, a qualified life does not need to be established. The Limerick Generating Station surveillance procedures for the PPS adequately address the IEEE 323 criteria. The Electric Power Research Institute also conducted a similar program. Results from the program concluded that only a few components are considered to have seismic/age-related sensitivity. Therefore, use of industry/vendor information to extrapolate beyond existing qualification test data when determining the design life.

The design life of the plant is equivalent to 40 years. The design life of the equipment is the time during which satisfactory performance can be expected for a specific set of service conditions. Equipment known as age-sensitive and thermal sensitive may require special maintenance procedures or replacement schedules to address the materials' cycle limitations. The supporting technical documentation defines the equipment known to be age-sensitive and thermal sensitive, and the procedure for maintaining qualification for the design life. This, coupled with the utilitys maintenance and surveillance program and other qualification requirements, ensures that the equipment performs its intended functions established for the design life.

RAI-45, PARTS a) and b)

The application is unclear as to how vibrations of the fiber optic cables described in Specification No. NE-381 will be addressed. Failure of a fiber optic cable connector assembly may occur through the long-term exposure to fatigue damaging events, such as cyclic or continuous low amplitude random vibration associated with its in-service installation or during a seismic the accumulated damage caused by cyclic or continuous stress-induced vibration loadings over the expected installed life of the equipment is known as vibration fatigue damage.

a) Please describe how vibration (non-seismic) aging will be addressed in the qualification process for fiber optic cable connections.

b) Please describe how seismic vibrations will be addressed in the qualification process for fiber optic cable connections.

CEG RESPONSE TO RAI-45, PARTS a) and b)

Vibration (non-seismic) aging is not required based on the installation location of the cable and connectors. The fiber optic cable connectors are in the PPS cabinet which is bolted

Response to RAI-38 and -42 through -46 (Proprietary)

LGS Digital Modernization Project Page 6 of 6 Docket Nos. 50-352 and 50-353 ATTACHMENTS 1 AND 2 TRANSMITTED HEREWITH CONTAINS PROPRIETARY INFORMATION - WITHHOLD UNDER 10 CFR 2.390 When separated, the cover letter, Attachment 3, Attachment 4,, and Attachment 6 are decontrolled down for seismic integrity and with no rotating or other vibration inducing equipment on or near the cabinet. The fiber optic cable installation location is limited to the control enclosure at Limerick Generating Station. The cable installation location is limited to the Control Enclosure, specifically the Control Room, Plant Generator Control Center, and Cable Spreading Room. These locations for where the fiber optic cables are being installed are in a mild environment. The installation of these cables are installed inside Instrumentation and Control cabinets or cable raceway located in the Control Enclosure and not in, on, or near rotating or vibrating equipment. No significant aging mechanisms have been identified for the Class 1E I&C equipment that are located in a mild environment. Therefore, there is not requirement for vibration (non-seismic) aging.

RAI-46, PARTS a) and b)

The application is unclear as to how radiation exposure of the fiber optic cables described in Specification No. NE-381 will be addressed. Given that fiber optic cable recovery following radiation exposure tends to increase over time:

a) Please explain how the qualification plan accounts for this phenomenon. Specifically, discuss the potential effects on signal integrity and attenuation.

b) Please discuss how the effects are evaluated during the qualification process.

CEG RESPONSE TO RAI-46, PARTS a) and b):

Radiation exposure consideration is not required based on the installation location of the cable. The cable installation location is limited to the Control Enclosure, specifically the Control Room, Plant Generator Control Center, and Cable Spreading Room. These locations where the fiber optic cables are being installed are in a mild environment. Station calculations identify the environmental service condition and the maximum dose rate during normal operating conditions and dose during design basis loss of coolant accident (LOCA) /

high energy line break (HELB). These dose rates are consistent with a mild environment. No significant aging mechanisms have been identified for the Class 1E I&C equipment that are located in a mild environment. Therefore, the effects of radiation exposure of the fiber optic cable and associated recovery following exposure is not evaluated during the qualification process.

WEC Affidavit CAW-25-002 (Non-Proprietary)

LGS Digital Modernization Project Docket Nos. 50-352 and 50-353 ATTACHMENTS 1 AND 2 TRANSMITTED HEREWITH CONTAINS PROPRIETARY INFORMATION - WITHHOLD UNDER 10 CFR 2.390 When separated, the cover letter, Attachment 3, Attachment 4,, and Attachment 6 are decontrolled ATTACHMENT 5 Non-Proprietary Limerick Generating Station, Units 1 and 2 NRC Docket Nos. 50-352 and 50-353 WEC Affidavit CAW-25-036 For Proprietary Information in Attachment 1 (4 pages)

• • • This record was final approved on 07/10/2025 11:03:41. (This statement was added by the PRIME system upon its validation)

Westinghouse Non-Proprietary Class 3 AFFIDAVIT CAW-25-036 Page 1 of 3 Commonwealth of Pennsylvania:

County of Butler:

(1)

I, Jerrod Ewing, Manager, Operating Plants Licensing; Cranberry Township, PA, have been specifically delegated and authorized to apply for withholding and execute this Affidavit on behalf of Westinghouse Electric Company LLC (Westinghouse).

(2)

I am requesting the proprietary portions of LIM-25-014-P, Revision 2 be withheld from public disclosure under 10 CFR 2.390.

(3)

I have personal knowledge of the criteria and procedures utilized by Westinghouse in designating information as a trade secret, privileged, or as confidential commercial or financial information.

(4)

Pursuant to 10 CFR 2.390, the following is furnished for consideration by the Commission in determining whether the information sought to be withheld from public disclosure should be withheld.

(i)

The information sought to be withheld from public disclosure is owned and has been held in confidence by Westinghouse and is not customarily disclosed to the public.

(ii)

The information sought to be withheld is being transmitted to the Commission in confidence and, to Westinghouses knowledge, is not available in public sources.

(iii)

Westinghouse notes that a showing of substantial harm is no longer an applicable criterion for analyzing whether a document should be withheld from public disclosure. Nevertheless, public disclosure of this proprietary information is likely to cause substantial harm to the competitive position of Westinghouse because it would enhance the ability of competitors to provide similar technical evaluation justifications and licensing defense services for commercial power reactors without commensurate expenses. Also, public disclosure of the information would enable others to use the information to meet NRC requirements for licensing documentation without purchasing the right to use the information.

• • • This record was final approved on 07/10/2025 11:03:41. (This statement was added by the PRIME system upon its validation)

Westinghouse Non-Proprietary Class 3 AFFIDAVIT CAW-25-036 Page 2 of 3 (5)

Westinghouse has policies in place to identify proprietary information. Under that system, information is held in confidence if it falls in one or more of several types, the release of which might result in the loss of an existing or potential competitive advantage, as follows:

(a)

The information reveals the distinguishing aspects of a process (or component, structure, tool, method, etc.) where prevention of its use by any of Westinghouse's competitors without license from Westinghouse constitutes a competitive economic advantage over other companies.

(b)

It consists of supporting data, including test data, relative to a process (or component, structure, tool, method, etc.), the application of which data secures a competitive economic advantage (e.g., by optimization or improved marketability).

(c)

Its use by a competitor would reduce his expenditure of resources or improve his competitive position in the design, manufacture, shipment, installation, assurance of quality, or licensing a similar product.

(d)

It reveals cost or price information, production capacities, budget levels, or commercial strategies of Westinghouse, its customers or suppliers.

(e)

It reveals aspects of past, present, or future Westinghouse or customer funded development plans and programs of potential commercial value to Westinghouse.

(f)

It contains patentable ideas, for which patent protection may be desirable.

(6)

The attached documents are bracketed and marked to indicate the bases for withholding. The justification for withholding is indicated in both versions by means of lower-case letters (a) through (f) located as a superscript immediately following the brackets enclosing each item of information being identified as proprietary or in the margin opposite such information. These lower-case letters refer to the types of information Westinghouse customarily holds in confidence identified in Sections (5)(a) through (f) of this Affidavit.

• • • This record was final approved on 07/10/2025 11:03:41. (This statement was added by the PRIME system upon its validation)

Westinghouse Non-Proprietary Class 3 AFFIDAVIT CAW-25-036 Page 3 of 3 I declare that the averments of fact set forth in this Affidavit are true and correct to the best of my knowledge, information, and belief. I declare under penalty of perjury that the foregoing is true and correct.

Executed on: 7/10/2025 Signed electronically by Jerrod Ewing

• • • This record was final approved on 07/10/2025 11:03:41. (This statement was added by the PRIME system upon its validation)

CAW-25-036 Revision 0 Non-Proprietary Class 3

• • This page was added to the quality record by the PRIME system upon its validation and shall not be considered in the page numbering of this document.**

Approval Information Author Approval Ewing Jerrod Jul-10-2025 11:03:41 Files approved on Jul-10-2025

CEG Affidavit (Non-Proprietary)

LGS Digital Modernization Project Docket Nos. 50-352 and 50-353 ATTACHMENTS 1 AND 2 TRANSMITTED HEREWITH CONTAINS PROPRIETARY INFORMATION - WITHHOLD UNDER 10 CFR 2.390 When separated, the cover letter, Attachment 3, Attachment 4,, and Attachment 6 are decontrolled ATTACHMENT 6 Non-Proprietary Limerick Generating Station, Units 1 and 2 NRC Docket Nos. 50-352 and 50-353 CEG Affidavit CEG Procured Cable Fiber Optic Cable Equipment Qualification Testing For CEG Proprietary Information in Attachment 2 Dated July 8, 2025 (2 pages)

AFFIDAVIT for Table 3, CEG Procured Cable Fiber Optic Cable Equipment Qualification Testing Page 1 of 2 Constellation Energy Generation, LLC AFFIDAVIT Commonwealth of Pennsylvania:

County of Chester:

(1) I, Wendi Para, Sr. Manager - Licensing, have been specifically delegated and authorized to apply for withholding and execute this Affidavit on behalf of Constellation Energy Company, LLC (CEG).

(2) I am requesting Table 3 -- CEG Procured Cable Fiber Optic Cable Equipment Qualification Testing, be withheld from public disclosure under 10 CFR 2.390. This table contains acceptance criteria that is contained in CEG NE-381 Nuclear Safety Related Specification for Fiber-Optic Instrumentation & Control System Cable, which has previously been withheld from public disclosure under 10 CFR 2.390 (ML24124A043).

(3) I have personal knowledge of the criteria and procedures utilized by CEG in designating information as a trade secret, privileged, or as confidential commercial or financial information.

(4) Pursuant to 10 CFR 2.390, the following is furnished for consideration by the Commission in determining whether the information sought to be withheld from public disclosure should be withheld:

(i) The information sought to be withheld from public disclosure is owned and has been held in confidence by CEG and is not customarily disclosed to the public.

(ii) The information sought to be withheld is being transmitted to the Commission in confidence and, to CEG knowledge, is not available in public sources.

(iii) CEG notes that a showing of substantial harm is no longer an applicable criterion for analyzing whether a document should be withheld from public disclosure.

Nevertheless, public disclosure of this proprietary information is likely to cause substantial harm to the competitive position of CEG because it would enhance the ability of competitors to provide similar technical evaluation justifications and licensing defense services for commercial power reactors without commensurate expenses. Also, public disclosure of the information would enable others to use the information to meet NRC requirements for licensing documentation without purchasing the right to use the information.

(5) CEG has policies in place to identify proprietary information. Under that system, information is held in confidence if it falls in one or more of several types, the release of which might result in the loss of an existing or potential competitive advantage, as follows:

(a) The information reveals the distinguishing aspects of a process (or component, structure, tool, method, etc.) where prevention of its use by any of CEGs competitors without license from CEG constitutes a competitive economic advantage over other companies.

AFFIDAVIT for Table 3, CEG Procured Cable Fiber Optic Cable Equipment Qualification Testing Page 2 of 2 (b) It consists of supporting data, including test data, relative to a process (or component, structure, tool, method, etc.), the application of which data secures a competitive economic advantage (e.g., by optimization or improved marketability).

(c) Its use by a competitor would reduce their expenditure of resources or improve their competitive position in the design, manufacture, shipment, installation, assurance of quality, or licensing a similar product.

(d) It reveals cost or price information, production capacities, budget levels, or commercial strategies of CEG, its customers or suppliers.

(e) It reveals aspects of past, present, or future CEG or customer funded development plans and programs of potential commercial value to CEG.

(f) It contains patentable ideas, for which patent protection may be desirable.

(6) The attached submittal contains proprietary information throughout, for the reasons set forth in Sections (5) (a), (b), and (c) of this Affidavit. Accordingly, a redacted version would be of no value to the public.

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

Signed electronically by: ________________________

Wendi Para Sr. Manager - Licensing