L-21-140, 2020 Annual 10 CFR 50.46 Report of Changes to or Errors in Emergency Core Cooling System Evaluation Models

2020 Annual 10 CFR 50.46 Report of Changes to or Errors in Emergency Core Cooling System Evaluation Models

ML21176A137
Person / Time
Site:	Davis Besse
Issue date:	06/24/2021
From:	Tony Brown Energy Harbor Nuclear Corp
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-21-140
Download: ML21176A137 (3)

Text

energy Energy Harbor Nuclear Corp.

Davis-Besse Nuclear Power Station harbor 5501 N State Route 2 Oak Harbor, Ohio 43449 Terry J. Brown 419-321-7676 Site Vice President, Davis-Besse Nuclear June 24, 2021 L-21-140 10 CFR 50.46(a)(3)(ii)

A TIN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

SUBJECT:

Davis-Besse Nuclear Power Station, Unit No. 1 Docket No. 50-346, License No. NPF-3 2020 Annual 10 CFR 50.46 Report of Changes to or Errors in Emergency Core Cooling System Evaluation Models In accordance with 10 CFR 50.46(a)(3)(ii), Energy Harbor Nuclear Corp. hereby submits the 2020 annual report of changes to or errors in an emergency core cooling system (ECCS) evaluation model, or in the application of such model, for the Davis-Besse Nuclear Power Station, Unit No. 1. The attached report covers the period of January 1, 2020, to December 31, 2020.

There are no regulatory commitments contained in this letter. If there are any questions or if additional information is required, please contact Mr. Phil H. Lashley, Manager- Fleet Licensing, at 330-696-7208.

Attachment:

2020 Annual 10 CFR 50.46 Report of Changes to or Errors in Emergency Core Cooling System Evaluation Models cc: NRC Region Ill Administrator NRC Resident Inspector NRC Project Manager Utility Radiological Safety Board

Attachment L-21-140 2020 Annual 10 CFR 50.46 Report of Changes to or Errors in Emergency Core Cooling System Evaluation Models Page 1 of 2 Title 10 of the Code of Federal Regulations, Part 50, Section 50.46(a)(3) states that each holder of an operating license shall report to the Nuclear Regulatory Commission (NRC),

at least annually, each change to or error in an acceptable emergency core cooling system (ECCS) evaluation model (EM), or in the application of such a model, that affects the calculation of peak cladding temperature (PCT). The nature of the change or error and its estimated effect on the limiting ECCS analysis is to be included in the report.

During the 2020 calendar year, there was a 0oF change to the small break loss of coolant accident (SBLOCA) and large break loss of coolant accident (LBLOCA) PCT, with some changes or errors associated with the evaluation models currently being used to support the design basis at Davis-Besse.

Therefore, a net PCT change of 0oF from the end of 2019 to the end of 2020 is reported for the SBLOCA and LBLOCA analyses.

The estimated effects on the peak cladding temperatures for this reporting period are summarized in Table 1.

Attachment L-21-140 Page 2 of 2 Table 1 10 CFR 50.46 Summary for 2020 Plant Name: Davis-Besse Nuclear Power Station, Unit No. 1 LOCA Spectrum Mark-B-HTP LBLOCA Mark-B-HTP SBLOCA Utility Name: Energy Harbor Full-Core Full-Core PCT or PCT Change ()

2,078oF 1,371oF Licensing Basis at Beginning of 2020 Analyzed Analyzed 2020 Licensing Activity Reporting Item # Description PCT or PCT Change ()

Category BWNT LOCA EM Inside Cladding Initial Base 1 EM Change = 0oF = 0oF Metal Reacted Thickness Model Change BEACH Lower Plenum Pressure Elevation Head 2 EM Change = 0oF N/A Adjustment Model Change RELAP5/MOD2-B&W CFT Temperature Limit 3 EM Change = 0oF N/A Adjustment or the Refill Period Model Change 2,078oF 1,371oF Licensing Basis at End of 2020 Estimated Analyzed