RA-25-0090, AP1000 Combined License Application Departure Report Update and 10 CFR 50.46 Annual Update

AP1000 Combined License Application Departure Report Update and 10 CFR 50.46 Annual Update

ML25093A287
Person / Time
Site:	05200022, 05200023
Issue date:	04/03/2025
From:	Nolan M Duke Energy, Progress Energy Carolinas
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
RA-25-0090
Download: ML25093A287 (1)

Text

M. Christopher Nolan Vice President New Nuclear Generation Strategy& Regulatory Engagement 13225 Hagers Ferry Rd., MG011E Huntersville, NC 28078 (704) 382-7426 Chris.Nolan@duke-energy.com Serial: RA-25-0090 10 CFR 52, Appendix D, X.B April 3, 2025 10 CFR 50.46 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 SHEARON HARRIS NUCLEAR POWER PLANT, UNITS 2 AND 3 DOCKET NOS.52-022 AND 52-023

SUBJECT:

AP1000 Combined License Application Departure Report Update and 10 CFR 50.46 Annual Update

REFERENCE:

1. Letter from J. Scarola (Duke Energy) to U.S. Nuclear Regulatory Commission (NRC),

dated February 18, 2008, Application for Combined License Shearon Harris Nuclear Power Plant Units 2 and 3, (ADAMS Accession No. ML080580078).

2. Letter from M. Christopher Nolan (Duke Energy) to NRC, dated November 14, 2024, AP1000 Combined License Application (COLA) Departure Report Update and Annual Final Safety Analysis Report (FSAR) Update, (ADAMS Accession No. ML24326A233).

Duke Energy Progress, Inc. (DEP) submitted an application, dated February 18, 2008, for a combined license (COL) for two AP1000 advanced pressurized water reactors to be located at the Shearon Harris Nuclear Power Plant (HAR) Site (Reference 1). Part 7 of the application is entitled Departures and Exemption Requests. This letter provides an update to the report describing plant-specific departures from the AP1000 Design Control Document (i.e.,

Departures Report) as required by 10 CFR 52, Appendix D, paragraphs X.B.1 and X.B.3.b. The following reports are addressed by this letter:

Semi-Annual Departures Report Annual 10 CFR 50.46 Report Semi-Annual Departures Report. For the Shearon Harris Nuclear Power Plant, Units 2 and 3 during the period of November 1, 2024 (Reference 2) to April 3, 2025:

There have been no new departures or changes to the departures described in the COLA Part 7, Departures and Exemption Requests Annual 10 CFR 50.46 Report. In accordance with 10 CFR 50.46, Acceptance Criteria for Emergency Core Cooling Systems for Light-Water Nuclear Power Reactors, for HAR Units 2 and 3, a design certification holder is required to report to the NRC in accordance with 10 CFR 50.46(a)(3). This same regulation requires a similar report from any COL holder and COL applicant. The DEP COL application for HAR Units 2 and 3 incorporated by reference the AP1000 design certification document and thus, also utilize the peak cladding temperature

U.S. Nuclear Regulatory Commission RA-25-0090 Page2 calculations performed by Westinghouse Electric Company (WEC). As such, the WEC report, provided in the Enclosure, is applicable to HAR Units 2 and 3.

This letter contains no new regulatory commitments.

Please address any comments or questions regarding this matter to Lee Grzeck, Licensing Manager - New Nuclear Generation at (980) 373-1530.

Sincerely, M. Christopher Nolan Vice-President, New Nuclear Generation Strategy and Regulatory Engagement

Enclosure:

Letter from Rachel Christian, Westinghouse Electric Company, to the U.S. Nuclear Regulatory Commission, "1 0 CFR 50.46 Annual Report for the AP1000 Plant Design," Letter No. DCP _NRC_003349, dated March 24, 2025

U.S. Nuclear Regulatory Commission RA-25-0090 Page 3 cc:

M. Miller, U.S. NRC Region II Administrator J. Glisan, U.S. NRC Project Manager

U.S. Nuclear Regulatory Commission RA-25-0090 Enclosure Letter from Rachel Christian, Westinghouse Electric Company, to the U.S. Nuclear Regulatory Commission, 10 CFR 50.46 Annual Report for the AP1000 Plant Design, Letter No. DCP_NRC_003349, dated March 24, 2025

Westinghouse Non-Proprietary Class 3 Westinghouse Electric Company 1000 Westinghouse Drive Cranberry Township, Pennsylvania, 16066 USA AP1000 is a trademark or registered trademark 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

© 2025 Westinghouse Electric Company LLC All Rights Reserved U.S. Nuclear Regulatory Commission Document Control Desk 11555 Rockville Pike Rockville, MD 20852 Direct tel: 724-940-8117 e-mail: chris2r@westinghouse.com Your Ref:

Our Ref:

Docket No.52-006 DCP_NRC_003349 March 24, 2025

Subject:

10 CFR 50.46 Annual Report for the AP1000 Plant Design Pursuant to 10 CFR 50.46, Acceptance criteria for emergency core cooling systems for light-water nuclear power reactors, Westinghouse Electric Company, LLC is submitting this report to document emergency core cooling system (ECCS) evaluation model changes or errors for the 2024 Model Year (i.e., 01/01/2024 - 12/31/2024) that affect the peak cladding temperature (PCT) calculations for the AP1000 plant design.

As described below, the following AP1000 analysis of record (AORs) is reported:

AP1000 Design Certification AOR:

On December 30th, 2011, the U.S. Nuclear Regulatory Commission certified an amendment to the Design Certification Rule for the AP1000 plant. As such, AP1000 Design Control Document (DCD) Revision 19 documents the AOR for the AP1000 Design Certification. The limiting transient for the AP1000 Design Certification is the Best Estimate Large Break Loss-of-Coolant Accident (LBLOCA). Westinghouse last provided an annual reporting letter to the NRC in March 2024 (DCP_NRC_003348) which presented an estimated PCT of 2010°F for the LBLOCA evaluation. There are no new ECCS model changes that impact PCT for the 2024 model year.

The estimated PCT for LBLOCA remains at 2010°F and does not exceed the 10 CFR 50.46 (b)(1) acceptance criterion of 2200°F.

The summary of the PCT margin allocations and their bases for the AP1000 Design Certification AOR are provided in the Attachment 1.

By copy of this letter, COL Holders and COL Applicants are hereby notified of any changes or errors in the AP1000 standard plant design PCT calculations as required by 10 CFR 50.46(a)(3)(iii).

Westinghouse Non-Proprietary Class 3

© 2025 Westinghouse Electric Company LLC All Rights Reserved Questions or requests for additional information related to content and preparation of this information should be directed to Westinghouse. Please send copies of such questions or requests to the respective COL Holders and COL Applicants referencing the amended AP1000 Design Certification Rule for the AP1000 nuclear power plant. A representative for each COL Holder and COL Applicant is included on the cc: list of this letter.

Sincerely, Rachel Christian Manager, New Plants Licensing

/Attachments 1.

10 CFR 50.46 Annual Report for the AP1000 Design Certification AOR, 2024 Model Year Cc:

M. Hayes

- U.S. NRC S. Joseph

- U.S. NRC K. Lowery

- SNC R. Joyce

- SNC A. Chamberlain - SNC J. Douglass

- SNC A. Quarles

- SNC A. Zaremba

- Duke A. Brown

- NextEra A. Bowman

- Westinghouse M. Arnold

- Westinghouse Z. Harper

- Westinghouse D. McDevitt

- Westinghouse M. Barca

- Westinghouse L. Conner

- Westinghouse

Westinghouse Non-Proprietary Class 3

© 2025 Westinghouse Electric Company LLC All Rights Reserved 10 CFR 50.46 Annual Report for the AP1000 Design Certification AOR, 2024 Model Year

ERRORS IN THE LARGE BREAK LOCA VESSEL MODEL

Background

Several input errors were discovered in the AP1000TM plant WCOBRA/TRAC vessel model used for large break LOCA calculations with the ASTRUM evaluation model. The input errors result in isolated aspects of incorrect geometry modeling within the vessel model, including; an incorrect wetted perimeter in a portion of the upper plenum, an incorrect transverse flow area in the lower region of the downcomer, and an incorrect steel-based material for various unheated conductors.

These items are characterized as a closely related group of Non-Discretionary Changes in accordance with Section 4.1.2 of WCAP-13451.

Affected Evaluation Model(s) 2004 Westinghouse Realistic Large Break LOCA Evaluation Model Using ASTRUM Estimated Effect The errors were qualitatively evaluated, and the nature of the errors leads to an estimated peak cladding temperature impact of 0°F.

DCP_NRC_003349 Westinghouse Non-Proprietary Class 3 Page 4 of 6

© 2025 Westinghouse Electric Company LLC All Rights Reserved

2025 Westinghouse Electric Company LLC All Rights Reserved LOCA Peak Cladding Temperature (PCT) Summary Plant Name:

AP1000 EM:

ASTRUM (2004)

AOR

Description:

Best Estimate Large Break Summary Sheet Status: DCD AP1000 AP1K_LOCA-50.46_AP1K_DCD_ASTRUM - 1.1 V.V PCT (°F)

Reference #

Note #

ANALYSIS-OF-RECORD 1837 1

ASSESSMENTS*

Delta PCT

(°F)

Reference #

Note #

Reporting Year**

1.

Evaluation of Pellet Thermal Conductivity Degradation and Peaking Factor Burndown 139 2

2012

2.

Revised Heat Transfer Multiplier Distributions 11 3

2013

3.

Error in Burst Strain Application 23 4

2013 AOR + ASSESSMENTS PCT =

2010.0 °F The licensee should determine the reportability of these assessments pursuant to 10 CFR 50.46.

• • The Reporting Year refers to the annual reporting year in which this assessment was included.

REFERENCES 1 APP-GW-GL-700, Revision 19, AP1000 Design Control Document, June 2011.

2 LTR-LIS-12-288, Information Regarding the Evaluation of Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Burndown Including Analysis Input Changes for AP1000 Large Break LOCA Analysis, June 2012.

3 LTR-LIS-13-357, AP1000 Plant 10 CFR 50.46 Report for Revised Heat Transfer Multiplier Distributions, July 2013.

4 LTR-LIS-14-41, AP1000 Plant 10 CFR 50.46 Report for the HOTSPOT Burst Strain Error Correction, January 2014.

NOTES:

(a) None DCP_NRC_003349 Westinghouse Non-Proprietary Class 3 Page 5 of 6

2025 Westinghouse Electric Company LLC All Rights Reserved LOCA Peak Cladding Temperature (PCT) Summary Plant Name:

AP1000 EM:

NOTRUMP-AP AOR

Description:

Appendix K Small Break Summary Sheet Status: DCD AP1000 AP1K_LOCA-50.46_AP1K_DCD_Appendix_K_SBLOCA - 1.1 V.V PCT (°F)

Reference #

Note #

ANALYSIS-OF-RECORD 1370 1

(a)

ASSESSMENTS*

Delta PCT

(°F)

Reference #

Note #

Reporting Year**

1.

Adiabatic Heat-up Calculation 264 2

(a) 2010 AOR + ASSESSMENTS PCT =

1634.0 °F The licensee should determine the reportability of these assessments pursuant to 10 CFR 50.46.

• • The Reporting Year refers to the annual reporting year in which this assessment was included.

REFERENCES 1 APP-GW-GL-700, Revision 19, AP1000 Design Control Document, June 2011.

2 LTR-LIS-10-373, 10 CFR 50.46 Report for the Evaluation of AP1000 SBLOCA 10-inch Transient Adiabatic Heat-up Calculation, June 2010.

NOTES:

(a) This is an adiabatic heat-up calculated PCT.

DCP_NRC_003349 Westinghouse Non-Proprietary Class 3 Page 6 of 6