ML22083A145
| ML22083A145 | |
| Person / Time | |
|---|---|
| Site: | 05200006 |
| Issue date: | 03/18/2022 |
| From: | Harper Z Westinghouse, Westinghouse |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| DCP_NRC_003346 | |
| Download: ML22083A145 (11) | |
Text
Westinghouse Non-Proprietary Class 3 Westinghouse Electric Company 1000 Westinghouse Drive Cranberry Township, Pennsylvania, 16066 USA U.S. Nuclear Regulatory Commission Direct tel: 412-374-5093 Document Control Desk Direct fax: 724-940-8505 11555 Rockville Pike e-mail: harperzs@westinghouse.com Rockville, MD 20852 Your Ref: Docket No.52-006 Our Ref: DCP_NRC_003346 March 18, 2022
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 2021 Model Year (i.e., 01/01/2021 - 12/31/2021) that affect the peak cladding temperature (PCT) calculations for the AP1000 plant design.
As described below, two AP1000 analyses of record (AORs) are 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 2021 (DCP_NRC_003344) which presented an estimated PCT of 2010°F for the LBLOCA evaluation. There are no new ECCS model changes that impact PCT for the 2021 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.
AP1000 Vogtle Units 3 & 4 AOR:
In addition to the AOR for the AP1000 Design Certification, the NRC has approved the AP1000 Core Reference Report (WCAP-17524-P-A), a generic topical which includes an ECCS reanalysis in the context of 10 CFR 50.46. The AOR contained in the Core Reference Report (CRR) has also been approved for incorporation into the Vogtle Units 3 & 4 licenses via NRC License Amendment 52. Westinghouse last provided an annual reporting letter to the NRC in March 2021 (DCP_NRC_003344) which presented an estimated PCT of 2046°F for the LBLOCA evaluation. There are no new ECCS model changes that impact the limiting LBLOCA PCT for 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
© 2022 Westinghouse Electric Company LLC All Rights Reserved
Westinghouse Non-Proprietary Class 3 the 2021 model year. As such, the estimated PCT for LBLOCA is 2046°F and does not exceed the 10 CFR 50.46 (b)(1) acceptance criterion of 2200°F.
Additionally, changes as part of the Automatic Depressurization System (ADS) and Core Makeup Tank (CMT) design parameters changes included in LAR-19-009 constitute a reanalysis in the context of 10 CFR 50.46 for the small break loss of coolant accident (SBLOCA) analysis and have been approved for incorporation into the Vogtle Units 3&4 licenses via NRC License Amendments 176 (Unit 3) and 175 (Unit 4). There are no new ECCS model changes that impact the limiting SBLOCA PCT for the 2021 model year. The estimated LBLOCA PCT continues to be the limiting estimated PCT following the SBLOCA reanalysis.
The summary of the PCT margin allocations and their bases for the AP1000 Vogtle Units 3 & 4 AOR are provided in the Attachment 2.
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). This letter contains site-specific evaluations for Vogtle Units 3 & 4.
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.
Very truly yours, Zachary S. Harper Manager, Licensing Engineering
/Attachments
- 1. 10 CFR 50.46 Annual Report for the AP1000 Design Certification AOR, 2021 Model Year
- 2. 10 CFR 50.46 Annual Report for the AP1000 Vogtle Units 3 & 4 AOR, 2021 Model Year Cc:
M. Dudek - U.S. NRC A. Zaremba - Duke/Progress A. Schoedel - Westinghouse B. Smith - U.S. NRC S. Franzone - FPL M. Yuan - Westinghouse A. Chamberlain - SNC R. Orthen - FPL D. McDevitt - Westinghouse J. Baker - SNC D. Weaver - Westinghouse M. Sheaffer - Westinghouse E. Grant - SNC A. Konig - Westinghouse M. Barca - Westinghouse J. Douglass - SNC M. Corletti - Westinghouse M. Patterson - Westinghouse
© 2022 Westinghouse Electric Company LLC All Rights Reserved
DCP_NRC_003346 Westinghouse Non-Proprietary Class 3 Page 3 of 11 Attachment 1 10 CFR 50.46 Annual Report for the AP1000 Design Certification AOR, 2021 Model Year
© 2022 Westinghouse Electric Company LLC All Rights Reserved
DCP_NRC_003346 Westinghouse Non-Propietary Class 3 Page 4 of 11 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) 1985 Westinghouse Advanced Plant Small Break LOCA Evaluation Model with NOTRUMP 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.
DCP_NRC_003346 Westinghouse Non-Propietary Class 3 Page 5 of 11 LOCA Peak Cladding Temperature (PCT) Summary Plant Name: AP1000 Utility Name: Westinghouse Nuclear Power Plants EM: ASTRUM (2004)
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 Delta PCT Reporting ASSESSMENTS* (°F) Reference # Note # Year**
- 1. Evaluation of Pellet Thermal 2012 Conductivity Degradation and 139 2 Peaking Factor Burndown
- 2. Revised Heat Transfer 2013 11 3 Multiplier Distributions
- 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 2022 Westinghouse Electric Company LLC All Rights Reserved
DCP_NRC_003346 Westinghouse Non-Propietary Class 3 Page 6 of 11 LOCA Peak Cladding Temperature (PCT) Summary Plant Name: AP1000 Utility Name: Westinghouse Nuclear Power Plants 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)
Delta PCT Reporting ASSESSMENTS* (°F) Reference # Note # Year**
- 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.
2022 Westinghouse Electric Company LLC All Rights Reserved
DCP_NRC_003346 Westinghouse Non-Proprietary Class 3 Page 7 of 11 Attachment 2 10 CFR 50.46 Annual Report for the AP1000 Vogtle Units 3 & 4 AOR, 2021 Model Year
© 2022 Westinghouse Electric Company LLC All Rights Reserved
DCP_NRC_003346 Westinghouse Non-Propietary Class 3 Page 8 of 11 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) 1985 Westinghouse Advanced Plant Small Break LOCA Evaluation Model with NOTRUMP 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.
DCP_NRC_003346 Westinghouse Non-Propietary Class 3 Page 9 of 11 LOCA Peak Cladding Temperature (PCT) Summary Plant Name: Vogtle Unit 3 and Unit 4 Utility Name: Southern Nuclear Operating Company EM: ASTRUM (2004)
Description:
Best Estimate Large Break Summary Sheet Status: Current Vogtle Unit 3 SV3_LOCA-50.46_SV3_Base_ASTRUM - 1.3 V.V PCT (°F) Reference # Note #
ANALYSIS-OF-RECORD 1936 1 (a)
Delta PCT Reporting ASSESSMENTS* (°F) Reference # Note # Year**
- 1. Revised Heat Transfer 2013 11 2 Multiplier Distributions
- 2. Error in Burst Strain Application 23 3 2013
- 3. Design Change Rebaseline 2018 54 4,5 (b)
Evaluation
- 4. Evaluation of RCP Design 2019 22 6,7 (c)
Changes - LAR 189 AOR + ASSESSMENTS PCT = 2046.0 °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-17524-P-A, Revision 1, AP1000 Core Reference Report, May 2015.
2 LTR-LIS-13-357, AP1000 Plant 10 CFR 50.46 Report for Revised Heat Transfer Multiplier Distributions, July 2013.
3 LTR-LIS-14-41, AP1000 Plant 10 CFR 50.46 Report for the HOTSPOT Burst Strain Error Correction, January 2014.
4 LTR-LIS-18-393, Update to the Vogtle Units 3 & 4 LBLOCA and SBLOCA 10 CFR 50.46 PCT Summary Sheets for LAR-79, November 2018.
5 ND-17-2074 (ML18029A243), Containment Pressure Analysis (LAR-17-043), December 2017. Approved by NRC November 7, 2018 as Amendments 147 (VEGP Unit 3) and 146 (VEGP Unit 4) (ML18289A742).
6 LTR-LIS-17-39, AP1000 Plant Suggested 10 CFR 50.46 Reporting Text and Updated LBLOCA PCT Summary Sheet for Evaluation of Reactor Coolant Pump (RCP) Design Changes, January 2017.
7 ND-18-1147 (ML18243A459), Reactor Coolant System (RCS) Flow Coastdown (LAR-18-025), August 2018. Approved by NRC February 25, 2019 as Amendments 155 (VEGP Unit 3) and 154 (VEGP Unit 4) (ML19038A450).
2022 Westinghouse Electric Company LLC All Rights Reserved
DCP_NRC_003346 Westinghouse Non-Propietary Class 3 Page 10 of 11 NOTES:
(a) Value contains 2°F bias for PCT sensitivity to PRHR isolation, per Reference 1 response to CRR-008, Table 2 and Table 15.6.5-8.
(b) The design change rebaseline evaluation used current code versions and accounts for design changes up to May 5, 2014 and plant model error corrections.
(c) The RCP design changes evaluation assesses the impact of DCP 5338 (APP-GW-GEE-5338), which is tied to DCP 4880 (APP-GW-GEE-4880). The evaluated changes include updated homologous curves and small changes to the pump rated conditions and rotor inertia.
2022 Westinghouse Electric Company LLC All Rights Reserved
DCP_NRC_003346 Westinghouse Non-Propietary Class 3 Page 11 of 11 LOCA Peak Cladding Temperature (PCT) Summary Plant Name: Vogtle Unit 3 and Unit 4 Utility Name: Southern Nuclear Operating Company EM: NOTRUMP-AP AOR
Description:
Appendix K Small Break Summary Sheet Status: Current Vogtle Unit 3 SV3_LOCA-50.46_SV3_Future_Appendix_K_SBLOCA - 1.3 V.V PCT (°F) Reference # Note #
ANALYSIS-OF-RECORD 1099 1 AOR + ASSESSMENTS PCT = 1099.0 °F REFERENCES 1 ND-19-1142 (ML19273A953), Automatic Depressurization System (ADS) and Core Makeup Tank (CMT) Design Parameters (LAR-19-009), September 2019. Approved by NRC March 11, 2020 as Amendments 176 (VEGP Unit 3) and 175 (VEGP Unit 4) (ML20049A721/ML20049A808).
NOTES:
(a) None 2022 Westinghouse Electric Company LLC All Rights Reserved