ML052700569

RAI, TS Changes on Modes 1-4 Confirmatory Dose Analysis for Penetrations Use in Shield Building (Tac No. MC6569)

ML052700569
Person / Time
Site:	Watts Bar
Issue date:	10/13/2005
From:	Pickett D NRC/NRR/DLPM/LPD2
To:	Singer K Tennessee Valley Authority
Pickett , NRR/DLPM, 415-1364
References
TAC MC6569
Download: ML052700569 (4)

Text

October 13, 2005 Mr. Karl W. Singer Chief Nuclear Officer and Executive Vice President Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, Tennessee 37402-2801

SUBJECT:

WATTS BAR NUCLEAR PLANT, UNIT 1 REQUEST FOR ADDITIONAL INFORMATION TO SUPPORT CONFIRMATORY DOSE ANALYSIS REGARDING THE TEMPORARY USE OF PENETRATIONS IN THE SHIELD BUILDING DOME DURING MODES 1-4 (TAC NO. MC6569)

Dear Mr. Singer:

By letter dated April 4, 2005, Tennessee Valley Authority submitted an application for a temporary license amendment to the Watts Bar Nuclear Plant (WBN), Unit 1, technical specifications (TSs) that would allow them to use one of two penetrations in the Shield Building dome during normal power operation (Modes 1-4).

During the Cycle 6 refueling outage, two penetrations through the Shield Building dome were created in preparation for steam generator replacement activities during the Cycle 7 refueling outage. These penetrations were each closed with a steel hatch assembly prior to entering Mode 4 at the end of the outage. The proposed TS change will allow WBN Unit 1 to open one of the penetrations in the Shield Building dome up to 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> a day, 6 days a week while in Modes 1-4 during Cycle 7 operation. This action will continue until the start of the Cycle 7 refueling outage in the fall of 2006.

In order for the staff to complete its review of the subject license amendment submittal, we request that the licensee provide responses to the enclosed request for additional information.

Discussions with your staff indicate that you plan to respond to this request by November 15, 2005. If you have any questions about this request, please contact me at (301)-415-1364.

Sincerely,

/RA/

Douglas V. Pickett, Senior Project Manager, Section 2 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-390

Enclosure:

Request for Additional Information cc w/enclosure: See next page

ML052700569 NRR-088 OFFICE LPD2-2 PM:LPD2-2 LA:LPD2-2 SC:SPSB SC:LPD2-2 NAME MVaaler DPickett BClayton MKotzalas(A) MMarshall DATE 10/ 11 /05 10/ 12 /05 10/ 11 /05 10/ 04 /05 10/ 13 /05 Mr. Karl W. Singer Tennessee Valley Authority WATTS BAR NUCLEAR PLANT cc:

Mr. Ashok S. Bhatnagar, Senior Vice President Mr. Paul L. Pace, Manager Nuclear Operations Licensing and Industry Affairs Tennessee Valley Authority Watts Bar Nuclear Plant 6A Lookout Place Tennessee Valley Authority 1101 Market Street P.O. Box 2000 Chattanooga, TN 37402-2801 Spring City, TN 37381 Mr. Larry S. Bryant, General Manager Mr. Jay Laughlin, Plant Manager Nuclear Engineering Watts Bar Nuclear Plant Tennessee Valley Authority Tennessee Valley Authority 6A Lookout Place P.O. Box 2000 1101 Market Street Spring City, TN 37381 Chattanooga, TN 37402-2801 Senior Resident Inspector Mr. Robert J. Beecken, Vice President Watts Bar Nuclear Plant Nuclear Support U.S. Nuclear Regulatory Commission Tennessee Valley Authority 1260 Nuclear Plant Road 6A Lookout Place Spring City, TN 37381 1101 Market Street Chattanooga, TN 37402-2801 County Mayor P. O. Box 156 Mr. Michael D. Skaggs Decatur, TN 37322 Site Vice President Watts Bar Nuclear Plant Mr. Lawrence E. Nanney, Director Tennessee Valley Authority Division of Radiological Health P.O. Box 2000 Dept. of Environment & Conservation Spring City, TN 37381 Third Floor, L and C Annex 401 Church Street General Counsel Nashville, TN 37243-1532 Tennessee Valley Authority ET 11A Ms. Ann P. Harris 400 West Summit Hill Drive 341 Swing Loop Road Knoxville, TN 37902 Rockwood, Tennessee 37854 Mr. John C. Fornicola, Manager Mr. Glenn W. Morris, Manager Nuclear Assurance and Licensing Corporate Nuclear Licensing Tennessee Valley Authority and Industry Affairs 6A Lookout Place Tennessee Valley Authority 1101 Market Street 4X Blue Ridge Chattanooga, TN 37402-2801 1101 Market Street Chattanooga, TN 37402-2801 County Executive 375 Church Street Suite 215 Dayton, TN 37321

REQUEST FOR ADDITIONAL INFORMATION WATTS BAR NUCLEAR PLANT, UNIT 1 TEMPORARY USE OF PENETRATIONS IN SHIELD BUILDING DOME DURING MODES 1-4

1. What are the control room atmospheric dispersion factors (/Q values) used in the dose assessment for postulated releases from the openings in the shield building dome to

1) the control room air intakes, and 2) as a result of unfiltered inleakage? If these /Q values are bounded by values which were previously approved, please provide a reference citation and sufficient information to demonstrate that releases from these openings are bounded by the previously approved /Q values. Note that a comparison with previously approved values should be for point source releases. If inleakage of unfiltered air into the control room has been modeled using control room intake /Q values, please confirm (preferably based on the results of tracer gas testing) that there are no potential unfiltered inleakage pathways during emergency mode that could result in /Q values that are higher than the control room intake /Q values.

If the /Q values are new, please provide a copy of the meteorological data inputs and program outputs for any atmospheric dispersion computer codes (e.g., ARCON96) used to generate the /Q values. A discussion of assumptions and inputs that are not a direct follow-on from guidance associated with use of the models, the Watts Bar Updated Final Safety Analysis Report (UFSAR), or other docketed supplemental information (e.g., drawings) should also be provided. Please provide a site plan highlighting the locations of all potential accident release pathways and control room intake and unfiltered inleakage pathways. If possible, drawings should be approximately to scale and show true north.

2. What are the /Q values used in the dose assessment for postulated releases from the openings in the shield building dome to the exclusion area boundary and low population zone? If these values were previously approved (e.g., in another licensing action),

please provide a reference citation.

If the /Q values are new, please provide a copy of the meteorological data inputs and program outputs for any atmospheric dispersion computer codes (e.g., PAVAN) used to generate the /Q values. A discussion of assumptions and inputs that are not a direct follow-on from guidance associated with use of the models, the Watts Bar UFSAR, or other docketed supplemental information (e.g., drawings) should also be provided.

Enclosure