L-2019-179, CFR 50.46 - Emergency Core Cooling System LBLOCA 30-Day Report

CFR 50.46 - Emergency Core Cooling System LBLOCA 30-Day Report

ML19273A422
Person / Time
Site:	Seabrook
Issue date:	09/26/2019
From:	Parks W Florida Power & Light Co, NextEra Energy Seabrook
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-2019-179
Download: ML19273A422 (2)

Text

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September 26' 2019 L-2019-179 10 CFR50.46 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Re: N extEra Energy Seabrook, LLC Seabrook Station, Docket No. 50-443 10 CFR 50.46 - Emergency Core Cooling System LBLOCA 30-Day Report Florida Power & Light Company (FPL), on behalf ofNextEra Energy Seabrook, LLC, and pursuant to 10 CFR 50.46(a)(3)(ii), is submitting this letter to provide a 30-day report for the Seabrook Station for the emergency core cooling system analysis performed by Westinghouse Electric Company, LLC.

One error was identified by Westinghouse that affects the Large-Break (LB) LOCA model. As the reported error is of a O °F impact, the Peak Cladding Temperature (PCT) is unchanged and continues to remain within the limits. However, as the cumulative PCT change already exceeds 50

°F for the LBLOCA analysis, a 30-day 10 CFR 50.46 report must be issued. Evaluation of the reported error has concluded that re-analysis was not required.

This letter contains no new or revised regulatory commitments.

Should you have any questions regarding this report, please contact Mr. Steve Catron, Fleet Licensing Manager, at (561) 304-6206.

Very truly yours, William L. Parks Safety Assurance and Learning, General Manager Florida Power & Light Company Attachment (1) cc: USNRC Regional Administrator, Region I USNRC Project Manager, Seabrook Station USNRC Senior Resident Inspector, Seabrook Station Florida Power & Light Company 700 Universe Boulevard, Juno Beach, FL 33408

... 111:*

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., 10 CFR 50.46 Attachment 1 Page 1 of1 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 Year 155 °P 155 °P 2018 (Reference 2)

Prior 10 CPR 50.46 Changes or Errors Corrections - Year 2019 Error in Vapor Temperature Resetting Logic (Reference 0° P 0° P 3)

Error in the Implementation of the Vessel Interfacial 0° P 0° P Heat Transfer Limit (Reference 4)

New 10 CFR 50.46 Changes or Errors Corrections - Year 2019 0 op 0 op Error in the Core Barrel Wetted Perimeter Sum of 10 CPR 50.46 Changes or Errors Corrections 155 °P 155 °P The sum of the PCTfrom the most recent ana/ysis using an acceptable evaluation model and the estimates of PCT impactfor changes and errors 1939 °P < 2200 °P identified since this ana/ysis Error in the Core Barrel Wetted Perimeter I

A calculation error was discovered in a wetted perimeter input in the vessel component of the Best Estimate Large Break Loss-of-Coolant Accident (BE LOCA) analysis-of-record. An evaluation of the impact was performed on the current licensing-basis analysis results. The difference in the wetted perimeter due to the error is very small and would be expected to produce a negligible effect on the large break LOCA analysis results, leading to an estimated PCT impact of O °F.

References:

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

2. L-2019-057, W. Parks (FPL) 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," March 19, 2019.

3. L-2019-058, W. Parks (FPL) to U.S. Nuclear Regulatory Commission, "10 CFR 50.46 - Emergency Core Cooling System LBLOCA 30-Day Report," March 25, 2019.

4. L-2019-151, W. Parks (FPL) to U.S. Nuclear Regulatory Commission, "10 CFR 50.46 - Emergency Core Cooling System LBLOCA 30-Day Report," August 6, 2019.