ML11147A024
| ML11147A024 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 05/24/2011 |
| From: | Krich R Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| TAC ME2532 | |
| Download: ML11147A024 (3) | |
Text
Tennessee Valley Authority 1101 Market Street, LP 3R Chattanooga, Tennessee 37402-2801 R. M. Krich Vice President Nuclear Licensing May 24, 2011 10 CFR 50.90 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Watts Bar Nuclear Plant, Unit 1 Facility Operating License No. NPF-90 NRC Docket No. 50-390
Subject:
Response to Request for Additional Information Regarding Proposed License Amendment for Carbon Dioxide Fire Suppression System (TAC No. ME2532)
References:
- 1. Letter from TVA to NRC, "License Amendment Request and Response to Request for Additional Information Related to Carbon Dioxide Fire Suppression System (TAC No. ME0876)," dated October 30, 2009
- 2. Letter from NRC to TVA, "Watts Bar Nuclear Plant, Unit 1 - Request for Additional Information Regarding License Amendment Request for Carbon Dioxide Fire Suppression System Installed in Auxiliary Instrument Room (TAC No. ME2532)," dated April 22, 2011 By letter dated October 30, 2009 (Reference 1), the Tennessee Valley Authority (TVA) submitted a request to modify the Watts Bar Nuclear Plant, Unit 1 (WBN, Unit 1), Facility Operating License by adding an exception to License Condition 2.F regarding the Fire Protection Program. TVA proposed to revise License Condition 2.F to resolve a discrepancy between WBN's Fire Protection Report and NUREG-0847, Supplement 18, "Safety Evaluation Report Related to Operation of Watts Bar Nuclear Plant, Units 1 and 2, Docket Nos. 50-390 and 50-391," related to the carbon dioxide fire suppression system in the WBN, Unit 1, Auxiliary Instrument Room.
By letter dated April 22, 2011 (Reference 2), the NRC requested that additional information be submitted to support their review of the license amendment request. As discussed in Reference 2, this response is due by May 24, 2011.
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U.S. Nuclear Regulatory Commission Page 2 May 24, 2011 TVA's response to the NRC's Request for Additional Information is provided in the enclosure to this letter.
TVA has determined that the additional information provided by this letter does not affect the no significant hazards considerations associated with the proposed license amendment request. The license amendment request changes still qualify for a categorical exclusion from environmental review pursuant to the provisions of 10 CFR 51.22(c)(9).
There are no new regulatory commitments associated with this letter.
If you have any questions about this change, please contact Kara Stacy at (423) 751-3489.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on the 2 4 th day of May, 2011.
Respectfully, R. M. Krich
Enclosure:
Response to Request for Additional Information Regarding the Proposed License Amendment Related to Carbon Dioxide Fire Suppression System cc (Enclosure):
NRC Regional Administrator - Region II NRC Senior Resident Inspector - Watts Bar Nuclear Plant Director, Division of Radiological Health - State of Tennessee Department of Environment and Conservation
ENCLOSURE WATTS BAR NUCLEAR PLANT, UNIT 1 DOCKET NO. 50-390 Response to Request for Additional Information Regarding the Proposed License Amendment Related to Carbon Dioxide Fire Suppression System NRC Question 1 The National Fire Protection Association 12, 1973 Edition, Section 2421 (Code of Record) for WBN Unit 1 installation, Table 6, "Flooding Factors for Specific Hazards," specifies flooding factors for specific hazards. Confirm the flooding factor (12 cubic feet per pound (ft3/Ib) C0 2 or
- 0. 083 lb COWfl) used to calculate the quantity of the CO2 to protect the Auxiliary Instrument Room. Provide the calculated quantity in pounds of C0 2 to be injected into WBN Unit 1 Auxiliary Instrument Room.
TVA Response The quantity of CO 2 discharged into the Watts Bar Nuclear Plant (WBN), Unit 1 Auxiliary Instrument Room required to meet the criteria of National Fire Protection Association 12, 1973 Edition (NFPA-12) is established in TVA calculation EPM-THJ-102192, "CO 2 Fire Protection System Required Quantity." Revision 2 of EPM-THJ-102192 was issued on September 13, 1995, and was the calculation of record when the WBN, Unit 1, Facility Operating License was issued on February 7, 1996.
Section 5.8 of calculation EPM-THJ-102192, Rev. 2, specifically calculates the volume of CO 2 required to be injected into the WBN, Unit 1, Auxiliary Instrument Room with consideration of leakage from the space. Using a flooding factor of 0.083 lb C0 2/ft3 (from page 31 of NFPA-12, 1973) and a volume for the Auxiliary Instrument Room of 71,900 ft3, the calculation determined that a base amount of 5,968 lbs of CO 2 were required to be injected into the Auxiliary Instrument Room. Therefore, TVA confirms that the flooding factor of 0.083 lb C0 2/ft3 was used to calculate the quantity of the CO 2 to protect the Auxiliary Instrument Room. The calculation further determined that an additional 1,128 lbs were required to make up for known leakage paths. As a result, from Section 5.8 of calculation EPM-THJ-1 02192, the total calculated quantity of C02 to be injected into the WBN, Unit 1, Auxiliary Instrument Room is 7,096 lbs.
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