ML11209C406

Final Safety Analysis Report, Response to Chapter 12 Request for Additional Information

ML11209C406
Person / Time
Site:	Watts Bar
Issue date:	07/27/2011
From:	Stinson D Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
TAC ME2731
Download: ML11209C406 (5)

Text

Tennessee Valley Authority, Post Office Box 2000, Spring City, Tennessee 37381-2000 July 27, 2011 10 CFR 50.4(b)(6) 10 CFR 50.34(b)

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 - FINAL SAFETY ANALYSIS REPORT (FSAR) - RESPONSE TO CHAPTER 12 REQUEST FOR ADDITIONAL INFORMATION (RAI)

References:

1. TVA letter to NRC dated February 25, 2011, "Watts Bar Nuclear Plant (WBN)

Unit 2 - Final Safety Analysis Report (FSAR) - Response to Chapters 11 and 12 Request for Additional Information"

2. NRC letter to TVA dated August 27, 2010, "Watts Bar Nuclear Plant (WBN) -

Unit 2 - Request for Additional Information Regarding Licensee's Final Safety Analysis Report Amendment Related to Chapters 11, 'Radioactive Waste Management' and 12, 'Radiation Protection' (TAC No. ME2731)"

The purpose of this letter is to provide a commitment to update Unit 2 FSAR Section 12.3.4.1.3, "Area Monitor Calibration and Maintenance," based on agreements as to content in a TVA-NRC meeting held on July 25, 2011, in Rockville, Maryland. Enclosure 1 provides an advance copy of this FSAR section with the revised wording. This change will be included in a future FSAR amendment.

Prior to this meeting, TVA had planned to provide a revised response to Question 24 provided in Reference 1 and to respond to RAI number 8, containing five parts, previously received in Reference 2. However, based on meeting discussions, coupled with the need to provide an update to the above FSAR section, the need to respond to these RAls has been superseded.

U.S. Nuclear Regulatory Commission Page 2 July 27, 2011 provides the list of commitments provided in this letter.

If you have any questions, please contact Bill Crouch at (423) 365-2004.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 2 7 th day of July, 2011.

Respectfully, David Stinson Watts Bar Unit 2 Vice President

Enclosures:

1. Updated FSAR Section 12.3.4.1.3

2. List of Commitments cc (Enclosures):

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 I Watts Bar Nuclear Plant Updated FSAR Section 12.3.4.1.3, "Area Monitor Calibration and Maintenance" E1-1

WATTS BAR area monitors employ Geiger-Mueller type gamma detectors. Each detector has its own independent high-voltage power supply located on panel 0-M-12 or 1-,2-M-30 in the main control room.

The Reactor Building upper and lower compartment post accident monitors are redundant high range monitors which are required to meet the requirements of RG 1.97 and NUREG-0737.

12.3.4.1.2.2 Main Control Room Ratemeter (0-M-12, 1-,2-M-30)

Ratemeters are of solid-state construction containing a solid-state, high-voltage power supply. Alarms are provided on the ratemeter chassis for high radiation and instrument malfunction. Visual and audible alarms are provided for high radiation and instrument malfunction in the main control room.

12.3.4.1.2.3 Local Indicator-Alarm Panel With the exception of the main control room and Reactor Building upper and lower compartment post accident monitors, each monitor has a locally mounted panel which contains an indicator, a visual and audible high radiation alarm, and a power-on light.

12.3.4.1.2.4 Multipoint Recorders (Main Control Room O-M-12, 1-,2-M-31)

The area monitors, with the exception of the Reactor Building upper and lower compartment post accident monitors, are recorded on multipoint recorders on panel 0-M-1 2, which is in the MCR. The upper and lower compartment post accident monitors are input to the Integrated Computer System (ICS) for recording purposes.

12.3.4.1.2.5 Monitor Sensitivity and Range The ranges of the instrumentation provided are given in Table 12.3-4. The area monitors set points, adjustable over the entire range, are determined by the radiation control group based on operating background levels. The setpoints for the Reactor Building upper and lower compartment post accident monitors are determined by engineering analysis.

12.3.4.1.3 Area Monitor Calibration and Maintenance With the exception of the Reactor Building upper and lower compartment post accident monitors, periodic testing of each area monitor includes a channel calibration performed at least once per 22.5 months (18 months plus 25%), and a channel operational test (COT) performed every 3 months, or at a frequency established by analysis of calibration history to ensure performance with a 95% probability at a 95%

confidence level. Monitor testing is performed in accordance with licensing or TVA program requirements (Technical Specifications, Offsite Dose Calculation Manual (ODCM), or the TVA calibration program). Testing of the Reactor Building upper and lower compartment post accident monitors is performed in accordance with the Technical Specifications.

RADIATION PROTECTION DESIGN FEATURES 12.3-21 List of Commitments The purpose of this letter is to provide a commitment to update Unit 2 FSAR Section 12.3.4.1.3, "Area Monitor Calibration and Maintenance," based on the agreements as to content in a TVA-NRC meeting held on July 25, 2011, in Rockville, Maryland. This change will be included in a future FSAR amendment.

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