ML24158A591

CFR 50.46 LOCA Annual Report

ML24158A591
Person / Time
Site:	Prairie Island
Issue date:	06/06/2024
From:	Borgen T Northern States Power Company, Minnesota, Xcel Energy
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
L-Pl-24-029
Download: ML24158A591 (1)

Text

1}, Xcel Energy June 6, 2024 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Prairie Island Nuclear Generating Plant, Units 1 and 2 Docket Nos. 50-282 and 50-306 Renewed Facility Operating License Nos. DPR-42 and DPR-60 2023 10 CFR 50.46 LOCA Annual Report 1717 Wakonade Drive Welch, MN 55089 L-Pl-24-029 10 CFR 50.46

Reference:

1) Westinghouse Letter NSPM-LOCA-TM-A5-000003 "Prairie Island Units 1 and 2 10 CFR 50.46 Annual Notification and Reporting for 2023", dated February 12, 2024 Pursuant to 10 CFR 50.46(a)(3)(ii), Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (hereafter "NSPM"), hereby submits the 2023 annual report of changes and errors associated with the Prairie Island Nuclear Generating Plant (PINGP), Units 1 and 2 Emergency Core Cooling System (ECCS) analyses (Enclosure 1 ).

The peak cladding temperature (PCT) for PINGP Unit 1 and Unit 2 were unchanged since the last annual report for the LOCA analyses. The plant specific changes and errors (absolute value) since the last annual report are summarized below:

LBLOCA Unit 1 None SBLOCA Unit 1 None LBLOCA Unit 2 None SBLOCA Unit 2 None contains Reference 1.

If you have any questions about this submittal, please contact Carrie Seipp, Senior Regulatory Engineer, at 612-330-5576.

L-Pl-24-029 Page 2 Summary of Commitments This letter makes no new commitments and no revisions to existing commitments.

--z;;;,,('/t.. Timothy P. Borgen "' -

Plant Manager, Prairie Island Nuclear Generating Plant Northern States Power Company -Minnesota Enclosure ( 1) cc: Administrator, Region Ill, USNRC Project Manager, Prairie Island, USNRC Resident Inspector, Prairie Island, USNRC ENCLOSURE 1 Westinghouse Non-Proprietary Class 3

Westinghouse Electric Company

@Westinghouse 1000 Westinghouse Drive Cranberry Township, Pennsylvania, 16066 USA

Direct tel: (412)374-3054 e-mail: landon.conner@westinghouse.com

Our ref: NSPM-LOCA-TM-A5-000003

Prairie Island Units 1 and 2 10 CFR 50.46 Annual Notification and Reporting for 2023

Dear Sir or Madam:

This is a notification of 10 CFR 50.46 reporting information pertaining to the Westinghouse Electric Company Evaluation Models/analyses. As committed to in WCAP-13451, Westinghouse Methodology for Implementation of 10 CFR 50.46 Reporting, Westinghouse is providing an Annual Report for Emergency Core Cooling System (ECCS) Evaluation Model changes and errors for the 2023 model year. All necessary standardized reporting pages for any changes and errors for the Evaluation Models utilized for your plant(s) are enclosed, consistent with the commitment following the NUPIC audit in early 1999. Peak Clad Temperature (PCT) summary sheets are enclosed. All necessary revisions for any non-zero, non-discretionary PCT changes have been included. Changes with estimated PCT impacts of 0°F may not be presented on the PCT summary sheet. The Evaluation Model changes and errors (except any plant-specific errors in the application of the model) have been provided to the NRC via Westinghouse letter.

This information is for your use in making a determination relative to the reporting requirements of 10 CFR 50.46. The information that is provided in this letter was prepared in accordance with Westinghouse's Quality Management System (QMS). Please contact your LOCA plant cognizant engineer(s) (PCE), Samuel H. Gonsowski (412-374-2408) and Tristan A.Gibbons (412-374-2232), if there are any questions concerning this information.

Author: (Electronically Approved)* Verifier: (Electronically Approved)*

Landon A. Conner Samuel H. Gonsowski

Co-Verifier: (Electronically Approved)* Approved: (Electronically Approved)*

Tristan A. Gibbons Amy J. Colussy

Attachment:

10 CFR 50.46 Reporting Text and PCT Summary Sheets (9 Pages)

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

© 2024 Westinghouse Electric Company LLC All Rights Reserved Page 2 of 11

• • • This record was final approved on 02/12/2024 14:22:13. (This statement was added by the PRIME system upon its validation)

Attachment to NSPM-LOCA-TM-A5-000003 Page 1 of 9

ERROR IN FLOW AREA AND VOLUME OF THIMBLE COMPONENTS

Background

The reactor vessel thimble bypass flow is modeled in best-estimate (BE) loss-of-coolant accident (LOCA) analyses using three PIPE components, which represent the thimble bypass for peripheral low power assemblies, interior assemblies located under guide tubes, and interior assemblies not located under guide tubes. It was discovered that the number of assemblies modeled is inconsistent with the number of assemblies represented by one or more of the thimble components, leading to an incorrect flow area and volume for the affected thimble component(s). The correction of this error represents a Non-Discretionary Change 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 error was evaluated to have a negligible impact on the calculated results, leading to an estimated peak cladding temperature (PCT) impact of 0°F.

• • • This record was final approved on 02/12/2024 14:22:13. (This statement was added by the PRIME system upon its validation)

Attachment to NSPM-LOCA-TM-A5-000003 Page 2 of 9

GENERAL CODE MAINTENANCE

Background

Various changes have been made to enhance the usability of codes and to streamline future analyses. Examples of these changes include improving the input diagnostic checks; enhancing the code output; optimizing active coding; and eliminating inactive coding. These changes represent Discretionary Changes that will be implemented on a forward-fit basis in accordance with Section 4.1.1 of WCAP-13451.

Affected Evaluation Model(s) 2004 Westinghouse Realistic Large Break LOCA Evaluation Model Using ASTRUM Estimated Effect The nature of these changes leads to an estimated peak cladding temperature impact of 0°F.

• • • This record was final approved on 02/12/2024 14:22:13. (This statement was added by the PRIME system upon its validation)

Attachment to NSPM-LOCA-TM-A5-000003 Page 3 of 9

LOCA Peak Cladding Temperature (PCT) Summary Plant Name: PRAIRIE ISLAND 1 EM: NOTRUMP AOR

Description:

Appendix K Small Break Summary Sheet Status: Current

PRAIRIE ISLAND 1 NSP_LOCA-50.46_NSP_Base_Appendix_K_SBLOCA - 1.2 V.V

PCT (°F) Reference # Note #

ANALYSIS-OF-RECORD 959 1

AOR + ASSESSMENTS PCT = 959.0 °F

REFERENCES 1 LTR-LIS-08-158, Transmittal of Future Prairie Island Units 1 and 2 PCT Summaries, February 2008.

NOTES:

(a) None

Version: PRAIRIE ISLAND 1 NSP_LOCA-50.46_NSP_Base_Appendix_K_SBLOCA - 1.2 V.V

2024 Westinghouse Electric Company LLC All Rights Reserved Page 5 of 11

• • • This record was final approved on 02/12/2024 14:22:13. (This statement was added by the PRIME system upon its validation)

Attachment to NSPM-LOCA-TM-A5-000003 Page 4 of 9

LOCA Peak Cladding Temperature (PCT) Summary Plant Name: PRAIRIE ISLAND 1 EM: ASTRUM (2004)

AOR

Description:

Best Estimate Large Break Summary Sheet Status: IFBA/Gad

PRAIRIE ISLAND 1 NSP_LOCA-50.46_NSP_IFBA_GAD_ASTRUM - 1.3 V.V

PCT (°F) Reference # Note #

ANALYSIS-OF-RECORD 1765 1

Delta PCT Reporting ASSESSMENTS* (°F) Reference # Note # Year**

1. Revised Heat Transfer Multiplier Distributions -2 3 2013

2. Error in Burst Strain Application 25 4 2013

3. Evaluation of the Introduction of IFBA Fuel 0 2 2018

4. Evaluation of Fuel Pellet 2012 Thermal Conductivity 227 5 (a)

Degradation and Peaking Factor Burndown

AOR + ASSESSMENTS PCT = 2015.0 °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 WCAP-17783-P, Best-Estimate Analysis of the Large-Break Loss-of-Coolant Accident for Prairie Island Units 1 and 2 with Replacement Steam Generators Using ASTRUM Methodology, June 2013.

2 LTR-LIS-15-287, Rev. 1, Prairie Island Units 1 and 2, 10 CFR 50.46 Notification and Reporting for the Revised Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Burndown Evaluation and the Introduction of IFBA Fuel, September 2015.

3 LTR-LIS-13-366, Revision 1, Prairie Island Units 1 and 2 10 CFR 50.46 Report for Revised Heat Transfer Multiplier Distributions, August 2013.

4 LTR-LIS-14-50, Prairie Island Units 1 and 2 10 CFR 50.46 Report for the HOTSPOT Burst Strain Error Correction, January 2014.

5 LTR-LIS-12-414, Prairie Island Units 1 and 2, 10 CFR 50.46 Notification and Reporting for Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Burndown, September 2012.

Version: PRAIRIE ISLAND 1 NSP_LOCA-50.46_NSP_IFBA_GAD_ASTRUM - 1.3 V.V

2024 Westinghouse Electric Company LLC All Rights Reserved Page 6 of 11

• • • This record was final approved on 02/12/2024 14:22:13. (This statement was added by the PRIME system upon its validation)

Attachment to NSPM-LOCA-TM-A5-000003 Page 5 of 9

NOTES:

(a) This evaluation credits peaking factor burndown, see Reference 5.

Version: PRAIRIE ISLAND 1 NSP_LOCA-50.46_NSP_IFBA_GAD_ASTRUM - 1.3 V.V

2024 Westinghouse Electric Company LLC All Rights Reserved Page 7 of 11

• • • This record was final approved on 02/12/2024 14:22:13. (This statement was added by the PRIME system upon its validation)

Attachment to NSPM-LOCA-TM-A5-000003 Page 6 of 9

LOCA Peak Cladding Temperature (PCT) Summary Plant Name: PRAIRIE ISLAND 2 EM: NOTRUMP AOR

Description:

Appendix K Small Break Summary Sheet Status: Current

PRAIRIE ISLAND 2 NRP_LOCA-50.46_NRP_Base_Appendix_K_SBLOCA - 1.2 V.V

PCT (°F) Reference # Note #

ANALYSIS-OF-RECORD 959 1,2 a

AOR + ASSESSMENTS PCT = 959.0 °F

REFERENCES 1 LTR-LIS-08-158, Transmittal of Future Prairie Island Units 1 and 2 PCT Summaries, February 2008.

2 LTR-LIS-13-274, Prairie Island Units 1 and 2, 10 CFR 50.46 Summary Sheets for the Evaluation to Support the Unit 2 Installation of AREVA Model 56/19 Replacement Steam Generators (RSGs), June 2013.

NOTES:

(a) The Unit 1 AOR is applicable to Unit 2 with the RSGs installed.

Version: PRAIRIE ISLAND 2 NRP_LOCA-50.46_NRP_Base_Appendix_K_SBLOCA - 1.2 V.V

2024 Westinghouse Electric Company LLC All Rights Reserved Page 8 of 11

• • • This record was final approved on 02/12/2024 14:22:13. (This statement was added by the PRIME system upon its validation)

Attachment to NSPM-LOCA-TM-A5-000003 Page 7 of 9

LOCA Peak Cladding Temperature (PCT) Summary Plant Name: PRAIRIE ISLAND 2 EM: ASTRUM (2004)

AOR

Description:

Best Estimate Large Break Summary Sheet Status: IFBA/Gad

PRAIRIE ISLAND 2 NRP_LOCA-50.46_NRP_IFBA_GAD_ASTRUM - 1.5 V.V

PCT (°F) Reference # Note #

ANALYSIS-OF-RECORD 1765 1

Delta PCT Reporting ASSESSMENTS* (°F) Reference # Note # Year**

1. Revised Heat Transfer Multiplier Distributions -2 3 2013

2. Error in Burst Strain Application 25 4 2013

3. Evaluation of the Introduction of IFBA Fuel 0 2 2019

4. Evaluation of Fuel Pellet Thermal Conductivity Degradation and 227 5 (a),(b) 2012 Peaking Factor Burndown

AOR + ASSESSMENTS PCT = 2015 °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 WCAP-17783-P, Best-Estimate Analysis of the Large-Break Loss-of-Coolant Accident for Prairie Island Units 1 and 2 with Replacement Steam Generators Using ASTRUM Methodology, June 2013.

2 LTR-LIS-15-287, Rev. 1, Prairie Island Units 1 and 2, 10 CFR 50.46 Notification and Reporting for the Revised Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Burndown Evaluation and the Introduction of IFBA Fuel, September 2015.

3 LTR-LIS-13-366, Revision 1, Prairie Island Units 1 and 2 10 CFR 50.46 Report for Revised Heat Transfer Multiplier Distributions, August 2013.

4 LTR-LIS-14-50, Prairie Island Units 1 and 2 10 CFR 50.46 Report for the HOTSPOT Burst Strain Error Correction, January 2014.

5 LTR-LIS-12-414, Prairie Island Units 1 and 2, 10 CFR 50.46 Notification and Reporting for Fuel Pellet Thermal Conductivity Degradation and Peaking Factor Burndown, September 2012.

Version: PRAIRIE ISLAND 2 NRP_LOCA-50.46_NRP_IFBA_GAD_ASTRUM - 1.5 V.V

2024 Westinghouse Electric Company LLC All Rights Reserved Page 9 of 11

• • • This record was final approved on 02/12/2024 14:22:13. (This statement was added by the PRIME system upon its validation)

Attachment to NSPM-LOCA-TM-A5-000003 Page 8 of 9

NOTES:

(a) This evaluation credits peaking factor burndown, see Reference 5.

(b) The reporting text and line item originally identified for Unit 1 in Reference 5 is applicable to Unit 2 with RSGs.

Version: PRAIRIE ISLAND 2 NRP_LOCA-50.46_NRP_IFBA_GAD_ASTRUM - 1.5 V.V

2024 Westinghouse Electric Company LLC All Rights Reserved Page 10 of 11

• • • This record was final approved on 02/12/2024 14:22:13. (This statement was added by the PRIME system upon its validation)

Attachment to NSPM-LOCA-TM-A5-000003 Page 9 of 9

10 CFR 50.46 Reporting SharePoint Site Check:

EMs applicable to Prairie Island Units 1 and 2:

Realistic Large Break - ASTRUM (2004)

Appendix K Small Break - NOTRUMP

2023 Issues Transmittal Letter Issue Description None None

• • • This record was final approved on 02/12/2024 14:22:13. (This statement was added by the PRIME system upon its validation)