ML052210396

RAI Temporary Use of Penetrations in the Shield Building Dome During Modes1-4 (Tac No. MC6569)

ML052210396
Person / Time
Site:	Watts Bar
Issue date:	08/11/2005
From:	Pickett D NRC/NRR/DLPM/LPD2
To:	Singer K Tennessee Valley Authority
Pickett D, NRR/DLPM, 415-1364
References
TAC MC6569
Download: ML052210396 (4)

Text

August 11, 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 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.

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

ML052210396 NRR-088 OFFICE LPD2-2 PM:LPD2-2 LA:LPD2-2 SC:EMCB SC:LPD2-2 NAME MVaaler DPickett BClayton ADrozd(A) MMarshall by memo dated DATE 08 / 10 / 05 08 / 10 / 05 08 / 10 / 05 07 / 27 /05 08 / 11 / 05 Mr. Karl W. Singer Tennessee Valley Authority WATTS BAR NUCLEAR PLANT cc:

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

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

1. The Loss-of-Coolant Accident (LOCA) dose analysis that was performed to support the license amendment request credits filtration of the release by the Emergency Gas Treatment System (EGTS) after 15 minutes. The submittal states that the assumption is that the open shield building penetration can be closed by the prestaged dedicated individual within 12 minutes, which leaves 3 minutes for the EGTS to depressurize the annulus and enable filtration of the release. How long does it take for the EGTS to adequately depressurize the annulus after the penetration is closed? By what means do you ensure that this goal is met?

2. Considering that manual operation is used to close the shield building, have any analyses been performed to determine the impact that delaying the closure would have on the offsite and control room doses during a LOCA? Have sensitivity analyses been performed to determine how long closure may be delayed before Title 10 of the Code of Federal Regulations, Part 100 or General Design Criterion-19 dose criteria are exceeded?

3. With exception to the EGTS filtration and release timing assumptions, are all other inputs, assumptions and methods used in the LOCA dose analysis the same as those discussed in the Watts Bar Updated Final Safety Analysis Report (UFSAR), Revision 4, and summarized in UFSAR Table 15.5-6?

Enclosure