L-2022-168, and Point Beach Units 1 and 2 - 10 CFR 50.46 - Emergency Core Cooling System LBLOCA 30-Day Report

and Point Beach Units 1 and 2 - 10 CFR 50.46 - Emergency Core Cooling System LBLOCA 30-Day Report

ML22300A118
Person / Time
Site:	Point Beach, Seabrook, Turkey Point
Issue date:	10/26/2022
From:	Strand D Florida Power & Light Co
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
L-2022-168
Download: ML22300A118 (1)

Text

• FPL.

October 26, 2022 L-2022-168 10 CFR 50.46 ATTN: Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555 Re: Florida Power & Light Company Turkey Point Units 3 and 4, Docket Nos. 50-250, 50-251 NextEra Energy Seabrook, LLC Seabrook Station, Docket No. 50-443 NextEra Energy Point Beach, LLC Point Beach Units 1 and 2, Docket Nos. 50-266, 50-301 10 CFR 50.46 - Emergency Core Cooling System LBLOCA 30-Day Report Pursuant to 10 CFR 50.46(a)(3)(ii), Florida Power & Light provides the attached 30-day report for Turkey Point Nuclear Plant, Units 3 and 4, and as agent for its affiliates NextEra Energy Seabrook, LLC and NextEra Energy Point Beach, LLC, provides 30-day reports for Seabrook Station and Point Beach Nuclear Plant, Units 1 and 2. These 30-day reports identify an error in the emergency core cooling system analysis performed by Westinghouse Electric Company, LLC, described in the respective attachments to this letter.

One error was identified by Westinghouse that affects the Large-Break (LB) LOCA analyses. The LBLOCA error is related to a non-conservation of the deposited energy in the Large Break LOCA Evaluation methodology. A very small fraction of the redistributed energy was not being included in the core balance rods. The error has a negligible impact on the results of the LBLOCA analyses, leading to an estimated peak cladding temperature (PCT) impact of 0ºF.

As the reported error is of a 0°F impact, the PCT continues to remain within the limits. However, as the cumulative PCT change already exceeds 50 °F for the LBLOCA analysis, a 30-day 10CFR50.46 report must be issued. An evaluation of the reported error has concluded that re-analysis is not required.

This letter contains no new or revised regulatory commitments.

Florida Power & Light Company 15430 Endeavor Drive, Jupiter, FL 33478

L-2022-168 Page 2 of 2 Should you have any questions regarding this submission, please contact Mr. Kenneth Mack, Fleet Licensing Manager, at 561-904-3635.

Sincerely, Dianne Strand General Manager, Regulatoiy Affairs Attachments (3) cc: USNRC Regional Administrator, Region I USNRC Regional Administrator, Region II USNRC Regional Administrator, Region III USNRC Project Manager, Seabrook Station USNRC Project Manager, Turkey Point Nuclear Plant USNRC Project Manager, Point Beach Nuclear Plant USNRC Senior Resident Inspector, Seabrook Station USNRC Senior Resident Inspector, Turkey Point Nuclear Plant USNRC Senior Resident Inspector, Point Beach Nuclear Plant Florida Power & Light Company 15430 Endeavor Drive, Jupiter, FL 33478

ATTACHMENT 1 Florida Power & Light Company Turkey Point Units 3 and 4

L-2022-168 Attachment 1 Page 11 of 1 Table 1:

Turkey Point Units 3 and 4 Large Break LOCA PCT 30-Day Report Evaluation Methodology:

Westinghouse, "Realistic Large-Break LOCA Evaluation Methodology Using the Automated Statistical Treatment of Uncertainty Method (ASTRUM)," WCAP-16009-P-A, Revision 0, January 2005.

Evaluation Model PCT (Unit 3/Unit 4): 2152°F (Reference 1)

Net PCT Absolute PCT Effect Effect Unit3/Unit4 Unit 3/Unit 4 Prior 10 CPR 50.46 Changes or Error Corrections - up to Year

-28 °P 80 °P 2021 (Reference 2)

Prior 10 CPR 50.46 Changes or Errors Corrections - Year 2022 None None New 10 CPR 50.46 Changes or Error Corrections - Year 2022 Error in Non-Conservation of Energy in the 0 op 0 op Generalized Energy Deposition Model Sum of 10 CPR 50.46 Changes or Errors Corrections -28 °P 80 °P The sum of the PCT from the most recent analysis using an acceptable evaluation model and the estimates ofPCT impact 2124 °F < 2200 °F for changes and errors identified since this analysis Error in Non-Conservation of Energy in the Generalized Energy Deposition Model An error was identified related to Generalized Energy Deposition Model (GEDM) used within the WCOBRA/TRAC Realistic Large-Break LOCA Evaluation Methodology. Non-conservation of the deposited energy was discovered to exist, whereby a very small fraction of the redistributed energy was not being included in the core balance rods. The energy deposited to the hot rod and hot assembly was confirmed to be conserved and correct.

The error has a negligible impact on the results of LBLOCA analyses, leading to an estimated peak cladding 0

temperature (PCT) impact of O F.

References:

1. Letter from M. Kiley to U.S. Nuclear Regulatory Commission, "Response to NRC Reactor Systems Branch Request for Additional Information Regarding Extended Power Uprate License Amendment Request No. 205 and Thermal Conductivity Degradation," L-2012-019, January 16, 2012.

2. Letter from T. Lesniak to U.S. Nuclear Regulatory Commission, "10 CFR 50.46 Annual Reporting of Changes to, or Errors in Emergency Core Cooling System Models or Applications," L-2022-039, April 14, 2022.

ATTACHMENT 2 N extEra Energy Seabrook Station

L-2022-168 Attachment 2 Page 11 of 1 Table 1:

Seabrook Unit 1 Large Break LOCA PCT 30-Day Report Evaluation Methodology:

Westinghouse, "Code Qualification Document for Best Estimate LOCA Analysis," WCAP-12945-P-A, March 1998.

Evaluation Model PCT: 1784 °F (Reference 1)

Net PCT Absolute PCT Effect Effect Prior 10 CPR 50.46 Changes or Error Corrections - up to 155 °P 155 °P Year 2021 (Reference 2)

Prior 10 CPR 50.46 Changes or Error Corrections - Year None 2022 New 10 CPR 50 .46 Changes or Error Corrections - Year 2022 Error in Non-Conservation of Energy in the 0 op 0 op Generalized Energy Deposition Model Sum of 10 CPR 50.46 Changes or Errors Corrections 155 °P 155 °P The sum of the PCT from the most recent analysis using an acceptable evaluation model and the estimates ofPCT 1939 °F < 2200 °F impact for changes and errors identified since this analysis Error in Non-Conservation of Energy in the Generalized Energy Deposition Model:

An error was identified related to Generalized Energy Deposition Model (GEDM) used within the WCOBRA/TRAC Realistic Large-Break LOCA Evaluation Methodology. Non-conservation of the deposited energy was discovered to exist, whereby a very small fraction of the redistributed energy was not being included in the core balance rods. The energy deposited to the hot rod and hot assembly was confirmed to be conserved and correct.

The error has a negligible impact on the results ofLBLOCA analyses, leading to an estimated peak cladding temperature (PCT) impact of O 0 P.

References:

1. Letter from M. Warner to U.S. Nuclear Regulatory Commission, "License Amendment Request 04-03, Application for Stretch Power Uprate," NYN-04016, March 17, 2004.

2. Letter from T. Lesniak to U.S. Nuclear Regulatory Commission, "10 CPR 50.46 Annual Reporting of Changes to, or Errors in Emergency Core Cooling System Models or Applications," L-2022-039, April 14, 2022.

ATTACHMENT 3 N extEra Energy Point Beach Units 1 and 2

L-2022-168 Attachment 3 Page 11 of 1 Table 1:

Point Beach Units 1 and 2 Large Break LOCA PCT 30-Day Report Evaluation Methodology:

Westinghouse, "Realistic Large-Break LOCA Evaluation Methodology Using the Automated Statistical Treatment of Uncertainty Method (ASTRUM)," WCAP-16009-P-A, January 2005.

Westinghouse, "Application of Best Estimate Large Break LOCA Methodology to Westinghouse PWRs with Upper Plenum Injection," WCAP-14449-P-A Revision 1, October 1999.

Evaluation Model PCT {Unit 1/Unit 2): 1975°F/1810°F Net PCT Effect Absolute PCT Effect Unit 1/Unit 2 Unit 1/Unit 2 Prior 10 CFR 50.46 Changes or Error Corrections - up to

+2 l 0°F/+248°F 2 l 0°F/340°F Year 2021 (Reference 1)

Prior 10 CFR 50.46 Changes or Error Corrections - Year None None 2022 New 10 CFR 50.46 Changes or Error Corrections - Year 2022 j Error in Non-Conservation of Energy in the oop;oop oop;oop Generalized Energy Deposition Model Sum of 10 CFR 50.46 Changes or Error Corrections +210°F/+248°F 210°F/340°F The sum of the PCT from the most recent analysis using an acceptable evaluation model and the estimates of PCT 2185°F/2058°F < 2200 °F impact for changes and errors identified since this analysis Error in Non-Conservation of Energy in the Generalized Energy Deposition Model An error was identified related to Generalized Energy Deposition Model (GEDM) used within the WCOBRA/TRAC Realistic Large-Break LOCA Evaluation Methodology. Non-conservation of the deposited energy was discovered to exist, whereby a very small fraction of the redistributed energy was not being included in the core balance rods. The energy deposited to the hot rod and hot assembly was confirmed to be conserved and correct.

The error has a negligible impact on the results of LBLOCA analyses, leading to an estimated peak cladding temperature (PCT) impact of 0 °F.

Reference:

1. L-2022-039, T. Lesniak (NextEra Energy) to US Nuclear Regulatory Commission Attn: Document Control Desk, "1 0CFR50.46 Annual Reporting of Changes to, or Errors in Emergency Core Cooling System Models or Applications," April 14, 2022.