ML14085A009

Supplemental Safety Evaluation Report 23, Appendix Hh, Open Item No. 67 - Component Cooling System Thermal Barrier Booster Pumps Above Possible Maximum Flood Level

ML14085A009
Person / Time
Site:	Watts Bar
Issue date:	03/20/2014
From:	Hruby R Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML14085A009 (3)

Text

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Tennessee Valley Authority, Post Office Box 2000, Spring City, Tennessee 37381-2000 March 20, 2014 10 CFR 50.4 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Watts Bar Nuclear Plant, Unit 2 NRC Docket No. 50-391

Subject:

WATTS BAR NUCLEAR PLANT (WBN) UNIT 2 - SUPPLEMENTAL SAFETY EVALUATION REPORT 23, APPENDIX HH, OPEN ITEM NO. 67 -

COMPONENT COOLING SYSTEM THERMAL BARRIER BOOSTER PUMPS ABOVE POSSIBLE MAXIMUM FLOOD LEVEL

References:

1. TVA letter to NRC dated June 13, 2012, "Commitments Related to Updated Hydrologic Analysis Results for Sequoyah Nuclear Plant, Units 1 and 2, and Watts Bar Nuclear Plant, Unit 1"

2. NRC Supplemental Safety Evaluation Report 23 dated July 2011, "Safety Evaluation Report Related to the Operation of Watts Bar Nuclear Plant (WBN) Unit 2"

3. TVA letter to NRC dated March 13, 2008, "Watts Bar Nuclear Plant (WBN) -

Unit 2 - Regulatory Framework for the Completion of Construction and Licensing for Unit 2 - Restructured Tables" The purpose of this letter is to revise a previous commitment related to the Component Cooling System (CCS) Thermal Barrier Booster Pumps. In Reference 3 at the start of the Unit 2 project, TVA committed to relocating the pumps due to an increased Probable Maximum Flood (PMF) level. However, since the initiation of the WBN Unit 2 completion project, the WBN PMF level has further increased.

As a result, TVA has determined that rather than relocating the CCS Thermal Barrier Booster Pumps to above the later PMF level, it would prefer to implement flood barrier modifications to prevent water damage to both units pumps in the event of a PMF. As of this date, WBN Unit 1 has already implemented these modifications as committed to in Reference 1, with WBN Unit 2 implementation of these modifications to be completed prior to Unit 2 licensing under Design Change Notice 54018.

U.S. Nuclear Regulatory Commission Page 2 March 20, 2014 In Reference 2, NRC had opened Appendix HH, Open Item No. 67 to track the original relocation action to above the PMF level. Therefore, this letter supersedes the previous commitment by implementing barrier modifications rather than relocating the pumps. The enclosure provides the revised commitment.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 2 0 th day of March, 2014.

Ifyou have any questions, please contact me at (423) 365-1260.

Respectfully, Raymond A. Hruby, Jr.

General Manager, Technical Services Watts Bar Unit 2

Enclosure:

Commitment List cc (Enclosure):

U. S. Nuclear Regulatory Commission Region II Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, Georgia 30303-1257 NRC Resident Inspector Unit 2 Watts Bar Nuclear Plant 1260 Nuclear Plant Road Spring City, Tennessee 37381

Enclosure Watts Bar Nuclear Plant Unit 2 Docket Number 50-391 Commitment List TVA will install flood barrier modifications to prevent water damage to WBN Unit 2 Component Cooling System Thermal Barrier Booster Pumps in the event of a Probable Maximum Flood before WBN Unit 2 receives an operating license.

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