ML17125A256

Emergency Core Cooling System Model Change Pursuant to the Requirements of 10 CFR 50.46, Submittal Schedule Commitment Change

ML17125A256
Person / Time
Site:	Surry
Issue date:	04/28/2017
From:	Mark D. Sartain Virginia Electric & Power Co (VEPCO)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML17125A256 (3)

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VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 April 28, 2017 10 CFR 50.46 U.S. Nuclear Regulatory Commission Serial No.17-158

• Attention: Document Control Desk NRA/GDM RO Washington, DC 20555 Docket Nos. 50-280/281 License Nos. DPR-32/37 VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNITS 1 AND 2 EMERGENCY CORE COOLING SYSTEM (ECCS) MODEL CHANGE PURSUANT TO THE REQUIREMENTS OF 10 CFR 50.46 SUBMITTAL SCHEDULE COMMITMENT CHANGE By letter dated July 10, 2012 (Reference 1), Virginia Electric and Power Company (Dominion) submitted information regarding an evaluation of fuel pellet thermal conductivity degradation (TCD) with fuel burnup in the Westinghouse Best Estimate Large Break Loss of Coolant Accident (LBLOCA) analysis methodology for Surry Power Station (SPS) Units 1 and 2 and its effect on peak cladding temperature (PCT). In addition, a commitment was made to submit to the NRC for review and approval a LBLOCA analysis that applies NRG-approved methods that include the effects of fuel pellet TCD.

A commitment due date of June 15, 2017 was indicated. The commitment date was based on the completion of two milestones that would allow a revised licensing basis LBLOCA analysis with an NRG-approved ECCS Evaluation Model (EM) that explicitly accounts for TCD. The two milestones are as follows:

1) NRC approval of a fuel performance analysis methodology that includes the effects of TCD. The new methodology for developing inputs to the LBLOCA EM would replace the current SPS licensing basis methodology in WCAP-15063-P-A, Revision 1 (Reference 2), which is referenced in Section 3.4 of the SPS Updated Final Safety Analysis Report (UFSAR).

2) NRC approval of a LBLOCA EM that includes the effects of TCD and accommodates the ongoing 10 CFR 50.46(c) rulemaking process. The new methodology would replace the current licensing basts analysis methodology in WCAP-16009-P-A (Reference 3), which is referenced in Section 14.5 of the SPS UFSAR.

The LBLOCA anal}'sis commitment for SPS Units 1 and 2 will utilize the Westinghouse FULL SPECTRUM' LOCA (FSLOCA') Evaluation Model with fuel rod inputs that explicitly account for fuel pellet TCD based on the Westinghouse PAD5 fuel performance code. The Westinghouse PAD5 topical report intended to replace the current SPS licensing basis method is presently in NRC review. As a result of the delay in completing the milestones for the analysis methodologies, the June 15, 2017

Serial No.17-158 Docket Nos. 50-280/281

,* Page 2 of 3 commitment date cannot be met. This letter revises the commitment date for submittal of the LBLOCA analysis for SPS Units 1 and 2 from June 15, 2017 to August 30, 2019.

The schedule is based on the expectation that the NRC will approve the topical report for PADS in 2017 and considers the overall plan for completing the SPS FSLOCA' analysis, which is in progress.

If you have any further questions regarding this submittal, please contact Mr. Gary D.

Miller at (804) 273-2771.

Respectfully, v~-

Mark D. Sartain Vice President~ Nuclear Engineering and Fleet Support Commitments made in this letter:

By August 30, 2019, Dominion will submit to the NRC for review and approval a LBLOCA analysis that applies an NRC-approved ECCS Evaluation Model that includes the effects of fuel pellet thermal conductivity degradation.

References:

1. Letter from J. Alan Price (Dominion) to USNRC, "Virginia Electric and Power Company (Dominion), Surry Power Station Units 1 and 2, 30-Day Report of Emergency Core Cooling System (ECCS) Model Changes Pursuant to the Requirements of 10 CFR 50.46," Dominion Serial No.12-420, July 10, 2012.

(ADAMS Accession No. ML12199A061)

2. WCAP-15063-P-A, Revision 1 with Errata, "Westinghouse Improved Performance Analysis and Design Model (PAD 4.0)," July 2000.

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

Serial No.17-158 Docket Nos. 50-280/281 Page 3 of 3

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• cc: U. S. Nuclear Regulatory Commission, Region II Regional Administrator Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, Georgia 30303-1257 NRC Senior Resident Inspector Surry Power Station Ms. K. R. Cotton Gross NRC Project Manager - Surry U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 08 G-9A 11555 Rockville Pike Rockville, MD 20852-2738 Ms. B. L. Mozafari NRC Project Manager - North Anna U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 08 H-12 11555 Rockville Pike Rockville, MD 20852-2738