BVY 13-041, License Amendment Request, Changes to 10 CFR 50.63 Licensing Basis, Supplement 4

License Amendment Request, Changes to 10 CFR 50.63 Licensing Basis, Supplement 4

ML13137A155
Person / Time
Site:	Vermont Yankee
Issue date:	05/14/2013
From:	Wamser C Entergy Nuclear Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
BVY 13-041
Download: ML13137A155 (4)

Text

Entergy Nuclear Operations, Inc.

Vermont Yankee 320 Governor Hunt Rd.

Entergy Vernon, VT 802-257-7711 Christopher J. Wamser Site Vice President BVY 13-041 May 14, 2013 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001

SUBJECT:

License Amendment Request; Changes to 10 CFR 50.63 Licensing Basis, Supplement 4 Vermont Yankee Nuclear Power Station Docket No. 50-271 License No. DPR-28

REFERENCES:

1. Letter, USNRC to Entergy Nuclear Operations, Inc., "Vermont Yankee Nuclear Power Station -Request for Additional Information Regarding Change to Licensing Basis for Station Blackout Diesel Generator (TAC NO. MF0422)," NVY 13-014, dated February 21, 2013

2. Letter, Entergy Nuclear Operations, Inc. to USNRC, "License Amendment Request; Changes to 10 CFR 50.63 Licensing Basis, Supplement 1'," BVY 13-019, dated March 19, 2013

Dear Sir or Madam:

In Reference 1, the NRC requested additional information (RAI) regarding a proposed change to the 10 CFR 50.63 (Station Blackout) licensing basis for Vermont Yankee Nuclear Power Station. In Reference 2, Entergy Nuclear Operations, Inc. (Entergy) provided the RAI responses to all questions except for RAI-1. Entergy committed to provide the response to RAI-1 by May 15, 2013. Attachment 1 to this submittal provides Entergy's response to RAI-1.

This supplement to the original license amendment request does not change the scope or conclusions in the original application, nor does it change Entergy's determination of no significant hazards consideration.

This letter contains no new regulatory commitments.

Should you have any questions concerning this letter or require additional information, please contact Mr. Robert Wanczyk at 802-451-3166.

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BVY 13-041 / Page 2 of 2 I declare under penalty of perjury that the foregoing is true and correct. Executed on May 14, 2013.

Sincerely, 04 CJW/plc Attachments: 1. Response to Request for Additional Information cc: William M. Dean Regional Administrator, Region 1 U.S. Nuclear Regulatory Commission 2100 Renaissance Blvd, Suite 100 King of Prussia, PA 19406-2713 Mr. Richard V. Guzman, Project Manager Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop O-8-C2 Washington, DC 20555 USNRC Resident Inspector Entergy Nuclear Vermont Yankee, LLC 320 Governor Hunt Road Vernon, Vermont 05354 Mr. Christopher Recchia Commissioner Vermont Department of Public Service 112 State Street - Drawer 20 Montpelier, Vermont 05620-2601

BVY 13-041 Docket 50-271 Attachment 1 Vermont Yankee Nuclear Power Station Response to Request for Additional Information

BVY 13-041 / Attachment 1 / Page 1 of 1 Response to Request for Additional Information (RAI)

By letter dated December 21, 2012 (Agencywide Documents Access and Management System Accession No. ML12362A041), Entergy Nuclear Operations, Inc. (Entergy or the licensee) submitted a license amendment request (LAR) to revise the licensing basis relative to how Vermont Yankee Nuclear Power Station (VYNPS) satisfies the requirements of Title 10 of the Code of FederalRegulations (10 CFR) Section 50.63, "Loss of all alternating current power." Entergy proposes to replace the Vernon Hydroelectric Station with an onsite emergency diesel generator (EDG) as the alternate alternating current (AAC) power source providing acceptable capability to withstand a station blackout (SBO) under 10 CFR 50.63(c)(2). The proposed change would involve revisions to the VYNPS facility and procedures described in the Updated Final Safety Analysis Report. The NRC staff is reviewing the LAR and has determined that additional information as requested below will be needed to support its review.

RAI 1

In the LAR, the licensee stated:

In Reference 7.a, the NRC accepted the determination that VY is categorized as an 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> coping plant with a target EDG reliability of 0.95. No changes to the station coping duration or credited EDG reliability are proposed in the amendment.

Based on the proposed design change, provide a summary of your detailed Regulatory Guide (RG) 1.155, "Station Blackout," analysis, considering the most up-to-date data (e.g., current grid reliability, loss of offsite power events, EDG reliability, etc.), showing the minimum specified duration that Vermont Yankee should be required to mitigate the consequences of an SBO event.

Response

A calculation (Reference 1) was performed, using the most up-to-date data, to determine the Station Blackout coping duration for the Vermont Yankee Nuclear Power Station (VY) using the methodology provided in Section 3 of NUMARC 87-00, Guidelines and Technical Bases for NUMARC Initiatives Addressing Station Blackout at Light Water Reactors, Revision 1.

According to Table 1 of RG 1.155, the coping duration methodology in Section 3 of NUMARC 87-00 is equivalent to that described in Section 3.1 of RG 1.155.

VY has been determined to fall into the following categories:

• Extreme Severe Weather (ESW) Group 3

• Severe Weather (SW) Group 2

• Offsite Power Group 13 As a result, VY is classified as being in offsite power design characteristic group P2. VY has been determined to be in Emergency AC (EAC) Group C. The allowed EDG target reliability is 0.95. Therefore, the Station Blackout coping duration for Vermont Yankee remains at 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

VY will update station documents, as necessary, to reflect the updated analysis.

REFERENCE:

1. AREVA Calculation 32-9203664-000, Vermont Yankee Nuclear Power Station Blackout Coping Duration Analysis