ML17243A005

Submittal of 10 CFR 50.46 30-Day Report

ML17243A005
Person / Time
Site:	Sequoyah
Issue date:	08/30/2017
From:	Anthony Williams Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML17243A005 (2)

Text

Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 August 30, 2017 10 CFR 50.4 10 CFR 50.46 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Sequoyah Nuclear Plant, Units 1 and 2 Renewed Facility Operating License Nos. DPR-77 and DPR-79 NRC Docket Nos. 50-327 and 50-328

Subject:

10 CFR 50.46 30-Day Report for Sequoyah Nuclear Plant, Units 1 and 2

References:

1. Letter from TVA to NRC, "10 CFR 50.46 Combined Annual and 30-Day Report for Sequoyah Nuclear Plant, Units 1 and 2" dated November 26, 2015(ML15336A940)

2. Letter from TVA to NRC, CNL-15-020 "10 CFR 50.46 Annual Report for Sequoyah Nuclear Plant, Units 1 and 2" dated November 28, 2016 (ML16334A315)

The purpose of this letter is to provide the 30-Day Report of changes or errors discovered in the emergency core cooling system (ECCS) evaluation model for Sequoyah Nuclear Plant (SQN) Units 1 and 2. This report is required in accordance with Title 10 of the Code of Federal Regulations (10 CFR) 50.46, "Acceptance Criteria for ECCS for Light-Water Nuclear Power Reactors," paragraph (a)(3)(ii), which states that a holder of an operating license or construction permit is required to report significant changes and errors affecting an ECCS evaluation model to the NRC within 30 days.

As defined in 10 CFR 50.46(a)(3)(i), a significant change affecting an ECCS evaluation model includes the cumulative sum of the absolute magnitudes of resulting peak cladding temperature (PCT) changes exceeding 50°F. This report is the result of an update to the loss of coolant accident (LOCA) Swelling and Rupture Model (SRM) used in the small break LOCA (SBLOCA) analysis and results in a 0°F change in PCT. As shown in reference 1, the accumulated changes and errors in the SBLOCA analysis are more than 50°F, so a 30-day report is required in accordance with 10 CFR 50.46(a)(3)(H).

U.S. Nuclear Regulatory Commission Page 2 August 30, 2017 10 CFR 50.46(a)(3)(ii) also requires the licensee to provide a proposed schedule for providing a reanalysis or taking other action as may be needed to show compliance with the 10 CFR 50.46 requirements. However, because the updated SRM results in no change in PCT, compliance with 10 CFR 50.46 requirements is demonstrated by references 1 and 2.

Therefore, TVA has concluded that no further action is required to show compliance with 10 CFR 50.46 requirements.

There are no regulatory commitments associated with this submittal. Should you have any questioDSrptease-opntact Mike McBrearty at (423) 843-7170 lony L. Williams Site Vice President Sequoyah Nuclear Plant cc:

NRC Regional Administrator - Region II NRC Senior Resident Inspector - Sequoyah Nuclear Plant NRC Project Manager - Sequoyah Nuclear Plant