ML15070A525

Request for Additional Information License Amendment Request to Adopt NFPA 805 Performance-Based Standard for Fire Protection for Light Water Reactor Generating Plants (TAC Nos. MF1185-87)

ML15070A525
Person / Time
Site:	Browns Ferry
Issue date:	03/12/2015
From:	Farideh Saba Plant Licensing Branch II
To:	James Shea Tennessee Valley Authority
Saba F DORL/LPL2-2 301-415-1447
References
TAC MF1185, TAC MF1186, TAC MF1187
Download: ML15070A525 (4)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 March 12, 2015 Mr. Joseph W. Shea Corporate Vice President, Nuclear Licensing Tennessee Valley Authority 1101 Market Street, LP 3D-C Chattanooga, TN 37402-2801

SUBJECT:

BROWNS FERRY NUCLEAR PLANT, UNITS 1, 2, AND 3 - REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO ADOPT NATIONAL FIRE PROTECTION ASSOCIATION STANDARD 805, "PERFORMANCE-BASED STANDARD FOR FIRE PROTECTION FOR LIGHT WATER REACTOR GENERATING PLANTS" (TAC NOS. MF1185, MF1186, AND MF1187)

Dear Mr. Shea:

By letter dated March 27, 2013, as supplemented by letters dated May 16 and December 20, 2013, and January 1, February 13, March 14, May 30, June 13, July 10, August 29, September 16, October 6, and December 17, 2014, Tennessee Valley Authority (the licensee, TVA) submitted a license amendment request to transition the fire protection licensing basis at the Browns Ferry Nuclear Plant, Units 1, 2, and 3, from Title 10 of the Code of Federal Regulations (10 CFR), Section 50.48(b), to 10 CFR 50.48(c), National Fire Protection Association Standard 805, "Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants."

The Nuclear Reguulatory Commission (NRC) staff reviewed the licensee's submittals and determined that additional information is needed. The enclosure to this letter contains the staff's followup request for additional information (RAI) specific to the probabilistic risk assessment (PRA). On February 25, 2015, the NRC staff forwarded, via electronic mail), a draft of the PRA RAI to the TVA staff. On March 9, 2015, the NRC staff and TVA staff held a conference call to provide the licensee with an opportunity to clarify any portion of the draft PRA RAI and discuss the timeframe for which TVA may provide the requested information. The finalized PRA questions are found in the enclosed RAI. As agreed to by the NRC staff and TVA staff during the March 9, 2015, conference call, TVA will respond to the finalized RAI by April 23, 2015.

If you have any questions, please contact me at 301-415-1447 or farideh.saba@nrc.gov.

Docket Nos. 50-259, 50-260, and 50-296

Enclosure:

Request for Additional Information cc w/enclosures: Distribution via Listserv Sincerely, Farideh E. Saba, Senior Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

REQUEST FOR ADDITIONAL INFORMATION LICENSE AMENDMENT REQUEST TO ADOPT NATIONAL FIRE PROTECTION ASSOCIATION STANDARD 805.

"PERFORMANCE-BASED STANDARD FOR FIRE PROTECTION FOR LIGHT WATER REACTOR GENERATING PLANTS" TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT. UNITS 1. 2. AND 3 DOCKET NOS. 50-259. 50-260. AND 50-296 Probabilistic Risk Assessment (PRA) Request for Additional Information (RAI) 01.r.01.01 In the letter dated December 17, 2014 (Agencywide Documents Access and Management System Accession No. ML14363A057), the revised response to Part (e) to PRA RAI 01.r.01 indicates that the fire ignition frequency for junction box fires is apportioned to individual scenarios within Physical Analysis Unit (PAU) 25-1 and the cable spreading room portion of PAU 16-A on the basis of cable tray length. The use of cable tray length as a frequency weighting factor for junction box fire scenarios is a deviation from accepted guidance in Frequently Asked Question (FAQ) 13-0006, which provides different weighting factors (i.e.,

number of junction boxes or the number of cables entering junction boxes). Justify this departure from FAQ 13-0006 guidance, or alternatively, justify that this deviation has insignificant impact on fire PRA Fire Probabilistic Risk Assessment risk results with respect to both the transition and the self-approval risk acceptance guidelines.

PRA RAI 25 In the letter dated December 17, 2014, the estimates for total delta large early release frequency (b.LERF) (i.e., minus (-)2.24E-05/year (yr), -1.82E-05/yr, and -1.86E-05/yr) provided in the revised Section W.2.2 for Units 1, 2, and 3, respectively, show a marked decrease from those provided in the original submittal (i.e., 1.93E-07/yr, 3.19E-08, and 1.18E-07/yr). Clarify the basis for this decrease.

Enclosure

ML15070A525 OFFICE LPL2-2/PM LPL2-2/LAiT LPL2-2/LA AP LA/BC NAME FSaba LRonewicz BClayton HHamzehee DATE 3/13/15 3/12/15 3/12/15 3/12/15