ML25317A711

Introduction of Lead Use Assemblies

ML25317A711
Person / Time
Site:	Peach Bottom  (DPR-056)
Issue date:	11/13/2025
From:	Para W Constellation Energy Generation
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
Download: ML25317A711 (1)

Text

200 Energy Way Kennett Square, PA 19348 www.ConstellationEnergy.com 10 CFR 50.4 November 13, 2025 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 Peach Bottom Atomic Power Station, Unit 3 Subsequent Renewed Facility Operating License No. DPR-56 NRC Docket No. 50-278

Subject:

Peach Bottom Atomic Power Station, Unit 3 Introduction of Lead Use Assemblies

Reference:

Letter from T. A. Ippolito (U. S. Nuclear Regulatory Commission) to R. E. Engle (General Electric Company), "Lead Test Assembly Licensing," dated September 23, 1981 (NRC ADAMS Accession No. ML20090B065)

The purpose of this letter is to notify the U. S. Nuclear Regulatory Commission of the use of Lead Use Assemblies (LUAs) as required by the referenced letter and the General Electric Standard Application for Reactor Fuel (GESTAR II). Constellation Energy Generation, LLC, (CEG) loaded eight Westinghouse TRITON11 LUAs as part of the Peach Bottom Atomic Power Station (PBAPS), Unit 3, Reload Cycle 26 during the PBAPS 2025 refueling outage. These bundles, also referred to as TRITON11 LUAs, are intended to operate for three cycles prior to being discharged, as part of a joint program with Westinghouse Electric Company, LLC (WEC) and Global Nuclear Fuel, LLC (GNF).

Consistent with PBAPS Technical Specifications Section 4.2.1, Fuel Assemblies the limited number of lead test assemblies are placed in non-limiting core location. provides a summary report of the WEC TRITON11 LUAs. Attachment 2 provides a summary report of the GNF evaluations performed in support of this initiative.

There is no proprietary information in this correspondence.

There are no regulatory commitments in this submittal.

If you have any questions or require further information, please contact Steve Flickinger at 267-533-5302 Respectfully, Wendi Para Sr. Manager, Licensing Constellation Energy Generation, LLC Para, Wendi E 2025.11.13 14:01:15 -05'00'

U.S. Nuclear Regulatory Commission Introduction of Lead Use Assemblies NRC Docket No. 50-278 November 13, 2025 Page 2

Enclosures:

1) NF-BCEG-25-024 TRITON11 Lead Use Assemblies Summary Report for Peach Bottom Atomic Power Station Unit 3 - (Non-Proprietary)

2) 009N9116NP - Global Nuclear Fuel TRITON11 LUAs in Peach Bottom cc:

Unit 3 Cycle 26 - (Non-Proprietary) w/o Enclosures USNRC Region I, Regional Administrator USNRC Senior Resident Inspector, PBAPS USNRC Project Manager, PBAPS

ENCLOSURE 1 NF-BCEG-25-024 TRITON11 Lead Use Assemblies Summary Report for Peach Bottom Atomic Power Station Unit 3 (Non-Proprietary)

Westinghouse Non-Proprietary Class 3 NF-BCEG-25-024 October 2025 Revision 0 TRITON11 Lead Use Assemblies Summary Report for Peach Bottom Atomic Power Station Unit 3

Westinghouse Non-Proprietary Class 3 TRITON11, ADOPT, HiFi, StrongHold, Optima3, and Low Tin ZIRLO are trademarks or registered trademarks of Westinghouse Electric Company LLC, its affiliates and/or its subsidiaries in the United States of America and may be registered in other countries throughout the world. All rights reserved. Unauthorized use is strictly prohibited. Other names may be trademarks of their respective owners.

• Electronically approved records are authenticated in the electronic document management system.

Westinghouse Electric Company LLC 1000 Westinghouse Drive Cranberry Township, PA 16066, USA

© 2025 Westinghouse Electric Company LLC All Rights Reserved NF-BCEG-25-024 Revision 0 TRITON11 Lead Use Assemblies Summary Report for Peach Bottom Atomic Power Station Unit 3 Brian Kleinfeldt*

USBWR Engineering October 2025 Reviewer: Brandon Drusbasky*

USBWR Engineering Approved: Kevin Lasswell*, Director USBWR Engineering

Westinghouse Non-Proprietary Class 3 ii NF-BCEG-25-024 October 2025 Revision 0 TABLE OF CONTENTS LIST OF FIGURES....................................................................................................................... iii LIST OF ABBREVIATIONS.......................................................................................................... iv 1

INTRODUCTION............................................................................................................... 1 1.1 TRITON11 FUEL DESIGN..................................................................................... 2 2

SUMMARY

........................................................................................................................ 3 3

REFERENCES.................................................................................................................. 5 4

FIGURES.......................................................................................................................... 6

Westinghouse Non-Proprietary Class 3 iii NF-BCEG-25-024 October 2025 Revision 0 LIST OF FIGURES Figure 1: TRITON11 Fuel Assembly............................................................................................. 6 Figure 2: TRITON11 Fuel Lattice.................................................................................................. 7

Westinghouse Non-Proprietary Class 3 iv NF-BCEG-25-024 October 2025 Revision 0 LIST OF ABBREVIATIONS ADOPT Advanced Doped Pellet Technology AM Additively Manufactured AOO Anticipated Operational Occurrence APLHGR Average Planar LHGR BWR Boiling Water Reactor CFR Code of Federal Regulations CMS Core Monitoring System CPR Critical Power Ratio ECCS Emergency Core Cooling System GDC General Design Criterion GE/GNF General Electric / Global Nuclear Fuel / GE Vernova LHGR Linear Heat Generation Rate LOCA Loss of Coolant Accident LTA Lead Test Assembly LUA Lead Use Assembly MAPLHGR Maximum Average Planar Linear Heat Generation Rate MCPR Minimum Critical Power Ratio SLCS Standby Liquid Control System SLMCPR Safety Limit Minimum Critical Power Ratio US NRC / NRC United States Nuclear Regulatory Commission

Westinghouse Non-Proprietary Class 3 1

NF-BCEG-25-024 October 2025 Revision 0 1

Introduction This report describes the eight TRITON11 Lead Use Assemblies (LUAs) for the Peach Bottom Atomic Power Station Unit 3. The eight TRITON11 LUAs will be loaded in Cycle 26 and are planned to be discharged at the end of Cycle 28. The objective of this program is for Constellation Energy to develop experience with Westinghouse boiling water reactor methods and fuel products.

The Peach Bottom Atomic Power Station Technical Specifications provide an allowance for a limited number of lead test assemblies (LTAs) that have not completed representative testing (TS 4.2.1) (Reference 1). The requirement listed in TS 4.2.1 states that the test assemblies are placed in non-limiting core regions. The TRITON11 fuel for this project has completed representative testing in plants outside the United States and its design has been submitted for review by the NRC (Reference 5). However, since TRITON11 fuel is not yet approved for use in the United States by the NRC, the TRITON11 fuel for Peach Bottom Unit 3 is considered lead use. The language of TS 4.2.1 considers both LTAs and LUAs as Lead Test Assemblies.

The NRC provided additional guidance via letter on the use of lead test assemblies and their regulatory path (Reference 2). This letter describes how a licensee can pursue operating LTAs under a 10CFR50.59 evaluation. A licensee would perform an evaluation to demonstrate that a limited number of LTAs would operate with more thermal and mechanical margin relative to co-resident fuel during normal operation, anticipated operational occurrences, and postulated accidents. The NRC also provides additional information concerning approved codes and methods. The guidance is that licensees should use approved methods where possible, but for instances where methods are not approved yet, a conservative evaluation should be performed using sound engineering judgement and analytical codes that reflect well established engineering principles.

The overall reload licensing effort for this project relies upon two key aspects; the first is the overall core response performed by the reload licensed core vendor, and the second is the individual bundle response which is evaluated by Westinghouse. Westinghouse utilizes a reload fuel design and safety analysis process described in the NRC approved topical, CENPD-300-P-A, Reference Safety Report for Boiling Water Reactor Reload Fuel (Reference 4). The reload design process includes three disciplines, thermal-mechanical design, nuclear design, and thermal-hydraulic design. The reload safety analysis process includes evaluations of normal operation, anticipated operational occurrences, accidents, and special events. Westinghouses reload methodology is applied to the TRITON11 LUAs to demonstrate that they will operate in non-limiting regions of the core during their lifetime in the reactor. Operating in non-limiting regions of the core ensures compliance with TS 4.2.1 for LTAs and demonstrates the applicability of Constellation and General Electrics reload analysis methods to TRITON11 LUA fuel.

Evaluations in Reference 3 have demonstrated that the TRITON11 LUAs will operate in non-limiting locations regarding linear heat generation rate (LHGR), average planar linear heat generation rate (APLHGR), and critical power ratio (CPR). TRITON11 LUAs will also operate in non-limiting locations concerning shutdown margin. The LUAs are shown to maintain sufficient margin for normal operation, transients, and design basis accidents, including model,

Westinghouse Non-Proprietary Class 3 2

NF-BCEG-25-024 October 2025 Revision 0 manufacturing, fuel type, material, and methodology uncertainties. These evaluations apply to the initial cycle the LUAs are loaded as well as subsequent cycles so long as the LUAs are operated in non-limiting core locations with similar margins to the initial cycle. Specific limitations on margins for thermal limits, exposure, and shutdown margin are summarized Reference 3.

Reference 3 demonstrates that the TRITON11 LUAs comply with all regulatory criteria including the General Design Criteria (GDC) of Title 10, CFR 50, Appendix A as they are applicable to fuel systems and the effect of the LUAs on reactor systems and the reload fuel that is inserted in the core at the same time as the LUAs. Specifically, this means that the Reload 50.59 Evaluation, which is valid for loading GNF3 reload fuel, will not be invalidated by loading eight TRITON11 LUAs instead of the GNF3 reference assemblies.

The TRITON11 LUAs will not be treated explicitly in the plant Core Monitoring System (CMS).

Input data as well as models in the CMS for the TRITON11 LUAs will be those that are valid for the GNF3 reference assemblies. The following general operational constraints apply to the TRITON11 LUAs in conjunction with fulfillment of the mechanical, nuclear, thermal-hydraulic, and safety-assessment design bases.

The LUAs shall not lead the core during normal operation.

The LUAs shall not lead the core during Anticipated Operational Occurrences (AOOs) and accidents.

The LUAs maximum rod average burnup shall not exceed 62 MWd/kgU.

The LUAs are discharged after their third 24-month cycle of operation.

The LUAs are not planned for sustained control rod exposure.

1.1 TRITON11 Fuel Design TRITON11 fuel is based on an 11x11 fuel rod lattice with 18 part-length fuel rods. The handling loads are born by the three centrally located Low Tin ZIRLOTM water rods. All 109 fuel rods are free standing on the bottom tie plate and feature ADOPTTM pellets and HiFiTM cladding with an inner liner. The X-750+ spacer grids follow the same design concepts as SVEA-96 Optima3TM.

The fuel channel is also made of Low Tin ZIRLO and features varying thickness to optimize flow cross-sectional area. TRITON11 also includes the additively manufactured StrongHold debris filter. Figure 1 and Figure 2 provide an overview of the TRITON11 design.

The TRITON11 LUAs designed for Peach Bottom were chosen to be 0.11 wt-% U-235 lower than the enrichment of the GNF3 fuel assemblies they replace in the core design. This reduction in enrichment combined with the gadolinia burnable poison design of the LUAs is demonstrated in Reference 3 to be bounded by the reload design of the resident GNF3 fuel.

Westinghouse Non-Proprietary Class 3 3

NF-BCEG-25-024 October 2025 Revision 0 2

Summary The evaluations performed in Reference 3 demonstrate the following for the introduction of eight TRITON11 LUAs to the Peach Bottom Unit 3 reactor core:

TRITON11 LUAs are mechanically compatible with co-resident fuel, fuel storage, and vessel internal components at Peach Bottom Unit 3 over the course of the lifetime of the fuel.

TRITON11 LUAs comply with all regulatory criteria including the General Design Criteria of Title 10, CFR 50, Appendix A.

TRITON11 LUAs meet all thermal-mechanical design criteria outlined in Reference 4 and Reference 6.

TRITON11 LUAs will not lead the Peach Bottom 3 core in thermal limits (LHGR, MAPLHGR, and MCPR).

TRITON11 LUAs will not result in a more limiting shutdown margin condition than the nominal GNF3 reload design.

TRITON11 LUAs are thermal-hydraulically compatible with Peach Bottom Unit 3 and the incumbent fuel.

TRITON11 LUAs will not contribute to the cycle SLMCPR value due to their low power location.

The Updated Final Safety Analysis Report (Reference 7) conclusions regarding postulated AOOs, accidents, and special events will not be invalidated by the insertion of TRITON11 LUAs.

Insertion of TRITON11 LUAs will not result in adverse effects to the Standby Liquid Control System.

TRITON11 LUAs can conservatively be monitored by Peach Bottoms Core Monitoring System as GNF3 assemblies with corresponding GNF3 thermal limits.

The core average response of the fast pressurization transients is unaffected by the introduction of TRITON11 LUAs loaded in the core.

Local maximum absolute LHGR and maximum local increase in LHGR during a fast transient are below the fuel rod design criteria for fuel temperature and cladding strain with significant margin.

Westinghouse Non-Proprietary Class 3 4

NF-BCEG-25-024 October 2025 Revision 0 The TRITON11 fuel LUAs will be preferentially loaded into core locations such that they will operate at a minimum of 10% less bundle and nodal power than the peak assembly in the core. For this reason, the LUAs will be far less limiting with respect to transient CPR and LHGR changes than the core limiting GNF3 fuel.

Inserting TRITON11 LUAs will not result in any limiting slow transients or events analyzed by steady state methods based on the excess margin in the LUA locations and the evaluations performed throughout the life cycle of the LUAs.

Inserting TRITON11 LUAs will not impact ECCS performance analysis and compliance with the existing GNF3 MAPLHGR limits will ensure that all 10CFR50.46 criteria are met.

TRITON11 LUAs are bounded by the current fuel handling accident analysis of record as the number of failed TRITON11 fuel rods in this event results in a smaller total quantity of radioactive material released.

All Seismic plus LOCA safety requirements are fulfilled for the introduction of TRITON11 LUAs to the Peach Bottom Unit 3 core.

TRITON11 LUAs can be safely shipped to and handled at the Peach Bottom Atomic Power Station.

The TRITON11 LUAs will remain bounded by the reload licensing methodology of GNF3 and will not affect any operation regimes including off rated and off normal parameters.

Westinghouse Non-Proprietary Class 3 5

NF-BCEG-25-024 October 2025 Revision 0 3

References

1. Peach Bottom Atomic Power Station Unit 3 Subsequent Renewed Facility Operating License, Technical Specifications (ML052720269)

2. NRC Letter ML18323A169, Letter from U.S. Nuclear Regulatory Commission to Nuclear Energy Institute, Entergy Services, Inc., and NextEra Energy,

Subject:

Clarification of Regulatory Path for Lead Test Assemblies, June 2019

3. NF-BCEG-25-010, TRITON11 Lead Use Assemblies Licensing Report for Peach Bottom Atomic Power Station Unit 3, Revision 0

4. CENPD-300-P-A, Reference Safety Report for Boiling Water Reactor Reload Fuel, Revision 0

5. WCAP-18951-P, TRITON11 Reference Fuel Design, Revision 1

6. NUREG-800, Standard Review Plan Section 4.2, Revision 3

7. Peach Bottom Atomic Power Station Units 2 and 3 Updated Final Safety Analysis Report (ML21110A638), Revision 28

Westinghouse Non-Proprietary Class 3 6

NF-BCEG-25-024 October 2025 Revision 0 4

Figures Figure 1: TRITON11 Fuel Assembly

Westinghouse Non-Proprietary Class 3 7

NF-BCEG-25-024 October 2025 Revision 0 Figure 2: TRITON11 Fuel Lattice

ENCLOSURE 2 009N9116NP Global Nuclear Fuel TRITON11 LUAs in Peach Bottom Unit 3 Cycle 26 (Non-Proprietary)

Global Nuclear Fuel Copyright 2025 Global Nuclear Fuel, All Rights Reserved 009N9116NP Revision 0 October 2025 Non-Proprietary Information TRITON11TM LUAs in Peach Bottom Unit 3 Cycle 26

009N9116NP REVISION 0 Non-Proprietary Information Page 2 of 9 INFORMATION NOTICE Proprietary information of GNF has been removed from this non-proprietary version of NEDC 33917P. The information removed was contained between opening double brackets ( (( ) and closing double brackets

( )) ).

IMPORTANT NOTICE REGARDING CONTENTS OF THIS REPORT Please Read Carefully The design, engineering, and other information contained in this document are furnished in accordance with the contract between Constellation Energy Generation and GNF, and nothing contained in this document shall be construed as changing the contract. The use of this information by anyone other than Constellation Energy Generation, or for any purpose other than that for which it is furnished by GNF is not authorized; and with respect to any unauthorized use, GNF makes no representation or warranty, express or implied, and assumes no liability as to the completeness, accuracy, or usefulness of the information contained in this document, or that its use may not infringe privately owned rights.

009N9116NP REVISION 0 Non-Proprietary Information Page 3 of 9 REVISION

SUMMARY

Rev #

Section Modified Revision Summary 0

N/A Initial Release

009N9116NP REVISION 0 Non-Proprietary Information Page 4 of 9 TABLE OF CONTENTS

1.0 INTRODUCTION

................................................................................................................. 5 2.0 EVALUATION PROCESS................................................................................................... 5 2.1 Neutronic Equivalence............................................................................................... 5 2.2 Thermal-Hydraulic Equivalence................................................................................. 5 2.3 Reactivity Margin Considerations............................................................................... 5 2.4 MCPR99.9% Evaluation and Thermal Margin Considerations...................................... 6 2.5 Transients.................................................................................................................. 6 2.6 Stability....................................................................................................................... 6 2.7 Loss of Coolant Accident (LOCA).............................................................................. 7 2.8 IMLTR and MELLLA+ Licensing Topical Reports (LTRs) Limitations and Conditions

................................................................................................................................... 7 3.0 GNF/GEH EVALUATIONS................................................................................................. 7 4.0

SUMMARY

.......................................................................................................................... 7 5.0 ACRONYMS........................................................................................................................ 8

6.0 REFERENCES

.................................................................................................................... 9

009N9116NP REVISION 0 Non-Proprietary Information Page 5 of 9

1.0 INTRODUCTION

Constellation Energy Generation (CEG) is considering introducing up to eight TRITON11TM Lead Use Assemblies (LUAs) at Peach Bottom Unit 3 Cycle 26. This report summarizes the approach taken to support this potential initiative along with a summary of the evaluations performed by Global Nuclear Fuel (GNF) and GE Hitachi Nuclear Energy (GEH). It is important to note that the reload licensing for Cycle 26 was performed using solely a full core of GNF3 fuel design.

2.0 EVALUATION PROCESS GNF created a process to address these LUAs by designing the TRITON11TM LUAs and the GNF3 bundles (in the proposed LUA locations) to be neutronically and thermal-hydraulically equivalent. When both designs have equivalent neutronic and thermal-hydraulic characteristics at the nodal level, adequate steady-state representation is assured leading to similar power distributions. That is, both fuel designs would experience similar bundle powers with similar axial power shapes. In addition, steady-state boundary conditions for the proposed LUA locations were provided to Westinghouse Electric Company (WEC) to facilitate the assessment of the TRITON11TM LUAs performance (see Reference 1).

2.1 Neutronic Equivalence Neutronic equivalence would be accomplished by matching lattice physics reactivities (hot/cold, uncontrolled/controlled k) for all lattices of interest. The matching of lattice physics characteristics is complicated by the use of different methodologies between WEC and GNF. To circumvent this issue, a reference GNF2 bundle with geometric and lattice physics results was provided to normalize both methodologies. GNF provided all pertinent k associated with the GNF3 bundles residing in the potential LUA locations (see Reference 2), and WEC designed the TRITON11TM LUAs to match those reactivities.

2.2 Thermal-Hydraulic Equivalence A detailed thermal-hydraulic evaluation was performed to compare characteristics of both designs with the same boundary conditions (i.e., bundle flow, bundle power, axial power shape, pressure, and inlet enthalpy). The observed results were subsequently characterized by a bundle coolant flow difference between the two designs, provided the same driving pressure drop (as well as other identical conditions). This bundle flow difference was then evaluated at the core level, and the results demonstrated that the impact on thermal/reactivity margins was negligible. It was shown that at the core level, based on the muted effect of the small number of TRITON11TM bundles, the GNF3 and TRITON11TM are considered thermal-hydraulically equivalent for LUA purposes. See Reference 3 for further details.

2.3 Reactivity Margin Considerations The Cold Shutdown Margin (CSDM) requirements for the control cells containing potential LUA locations were increased by 0.1% relative to the limiting location in the core. Also, for the beginning of cycle, face adjacent control cells CSDM requirement was increased by 0.05%

relative to the limiting location in the core. Although the bundles will be designed to be neutronically equivalent, the additional CSDM requirements were imposed for conservatism. See Reference 4 for further details.

009N9116NP REVISION 0 Non-Proprietary Information Page 6 of 9 2.4 MCPR99.9% Evaluation and Thermal Margin Considerations GNF calculated the MCPR99.9% value per the normal reload licensing process for the full core of GNF3, and WEC will evaluate the adequacy of the TRITON11TM LUAs under such value.

Although thermal margins cannot be calculated by GNF for TRITON11TM, the GNF3 bundles at the potential LUA locations were designed with 10% additional margin compared to the limiting locations for both Critical Power Ratio (CPR) and Linear Heat Generation Rate (LHGR) to aid in maintaining TRITON11TM LUAs as non-limiting.

2.5 Transients GEH provided WEC boundary conditions from GEHs transient analysis code for one of the eight LUA locations proposed for a limiting (or near limiting) fast transient and limiting core condition at full power such as generator load rejection with no bypass near end of cycle (See Reference 5).

Initial CPR (ICPR) and Minimum CPR (MCPR) data at the LUA location as well as the limiting location in the core were provided for the event that sets the Operating Limit MCPR (OLMCPR) for the base case application condition. Using this information, WEC will assess the performance of the TRITON11TM LUAs to assure adequate CPR performance.

For slow transients, an event of interest for the LUAs is the local event, the Rod Withdrawal Error (RWE). However, it is expected there is no impact from the local RWE event on the LUAs as it was confirmed that the LUA locations are in uncontrolled cells. Safety Communication (SC) 25-02 (Reference 6), consistent with GNF processes, ((` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` `

` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` `

` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` `

` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` `

` ` ` ` ` ` ` ` ` ` )). Additional evaluations would be required if the allowances outlined in SC 25-02 are exceeded.

For the limiting core wide transient thermal-mechanical events, the nodal power increases (both limiting change in power increase and limiting overpower achieved in a transient) at an LUA location were provided. Applying the conditions to TRITON11TM, WEC will assess the approximate margin to its thermal-mechanical requirements to ensure that the established limits for the LUAs will not impact the LHGR operating limits for the core.

2.6 Stability For the main Detect and Suppress Solution - Confirmation Density (DSS-CD) solution, the MCPR margins are not impacted since the LUAs are placed in non-limiting locations. Additionally, the TRITON11TM and GNF3 fuel types are found to be hydraulically compatible, and there is no single channel thermal-hydraulic instability issue for either fuel type. The Oscillation Power Range Monitor (OPRM) hardware will perform as designed.

For the backup stability solution (Backup Stability Protection (BSP) and Automated BSP), there is no flow compatibility issue found ((` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` ` )). Thus, the LUAs are compatible with the GNF3 fuel, and there is no single channel thermal-hydraulic instability issue. The existing BSP / Automated BSP regions would continue to be applicable for the core irrespective of whether the eight LUAs are loaded or not.

See Reference 7 for more details.

009N9116NP REVISION 0 Non-Proprietary Information Page 7 of 9 2.7 Loss of Coolant Accident (LOCA)

WEC will perform a LOCA evaluation to demonstrate that the GNF3 Maximum Average Planar LHGRs (MAPLHGRs) used for the LUA locations are adequate.

2.8 IMLTR and MELLLA+ Licensing Topical Reports (LTRs) Limitations and Conditions Appendices E and F of the Supplemental Reload Licensing Report (SRLR) will demonstrate continued compliance with all limitations and conditions of the Interim Methods Licensing Topical Report (IMLTR) and Maximum Extended Load Line Limit Analysis Plus (MELLLA+) licensing topical report for the full core of GNF3. The limitations and conditions of the IMLTR and MELLLA+

licensing topical reports that are fuel type dependent are related to methods applicability. Since the methods for licensing are applied to GNF3, should the LUAs be inserted in Cycle 26, the following considerations must be addressed by WEC/CEG to consider the limitations and conditions met:

The LHGR criteria are met for both steady-state and transient conditions, The MAPLHGR evaluations demonstrate LOCA criteria are met, and Limiting the bypass voiding to less than 5 percent in the LUA locations.

3.0 GNF/GEH EVALUATIONS Six primary analyses/evaluations were performed by GNF/GEH to support the potential introduction of TRITON11TM LUAs: The steady-state boundary conditions (Reference 1), the thermal-hydraulic compatibility (Reference 3), the control blade worth and CSDM evaluation (Reference 4), the transients boundary conditions (Reference 5), the single channel stability evaluation (Reference 7), and the seismic data support (Reference 8).

4.0

SUMMARY

CEG is considering introducing up to eight TRITON11TM LUAs at Peach Bottom Unit 3 Cycle 26.

The process outlined above coupled with the analysis provided by GNF/GEH along with the TRITON11TM assessment performed by WEC would support the basis to allow the introduction of TRITON11TM LUAs.

Provided WEC/CEG demonstrates in the LUA evaluations that thermal margins (LHGR/CPR) at steady-state and transient conditions and LOCA performance are adequate for the TRITON11TM based on the boundary conditions supplied by GNF/GEH, operation of the LUAs is bounded by the GNF3 reload licensing calculations.

009N9116NP REVISION 0 Non-Proprietary Information Page 8 of 9 5.0 ACRONYMS Acronym Explanation BSP Backup Stability Protection CEG Constellation Energy Generation CFR Code of Federal Regulations CPR Critical Power Ratio CSDM Cold Shutdown Margin DSS-CD Detect and Suppress Solution - Confirmation Density EFPD Effective Full Power Days EOC End Of Cycle GEH GE Hitachi Nuclear Energy GNF Global Nuclear Fuel ICPR Initial CPR IMLTR Interim Methods Licensing Topical Report LHGR Linear Heat Generation Rate LOCA Loss of Coolant Accident LTR Licensing Topical Report LUA Lead Use Assembly MAPLHGR Maximum Average Planar LHGR MCPR Minimum Critical Power Ratio MELLLA+

Maximum Extended Load Line Limit Analysis Plus OLMCPR Operating Limit MCPR OPRM Oscillation Power Range Monitor RWE Rod Withdrawal Error SC Safety Communication SRLR Supplemental Reload Licensing Report WEC Westinghouse Electric Company

009N9116NP REVISION 0 Non-Proprietary Information Page 9 of 9

6.0 REFERENCES

1. 009N5722 Revision 0, Data Transmittal to Support TRITON11 LUAs, February 2025.

2. 008N4921 Revision 0, Bundle Design Report - Bundle #5252, October 2024.

3. 009N3451 Revision 0, Thermal-Hydraulic Evaluation to Support TRITON11TM LUAs in Peach Bottom Unit 3 Cycle 26, March 2025.

4. 009N7806 Revision 1, Peach Bottom 3 (HE3) Cycle 26 LUA RBW SDM and Worth (NDR),

March 2025.

5. 008N6054 Revision 0, Peach Bottom 3 Cycle 26 LUA Project - Transient Analysis AOO Data

1. 3b, April 2025.

6. 009N8916 Revision 0, Safety Communication (SC) 25-02, Adequacy of Cycle-Specific Rod Withdrawal Error Transient Analyses, April 2025.

7. 009N7533 Revision 0, Peach Bottom Unit 3 (HE3) Cycle 26 Reload Stability TRITON 11 LUA Assessment Report, May 2025.

8. 009N8880 Revision 0, Peach Bottom 2&3 Design Input Request [Customer Letter with GNF3 Channel Design Inputs Relevant to Peach Bottom 2&3], April 2025.