NL-04-2489, Unit 2, Response to Request for Additional Information Regarding Fall 2002 Steam Generator Inspection
| ML043570226 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 12/17/2004 |
| From: | Stinson L Southern Nuclear Operating Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-04-2489 | |
| Download: ML043570226 (4) | |
Text
L M. Stinson (Mike)
Southern Nuclear Vice President Operating Company. Inc.
40 Inverness Center Parkway Post Office Box 1295 Birmingham, Alabama 35201 Tel 205.992.5181 Fax 205.992.0341 4
SOUTHERNHE December 17, 2004 COMPANJY Docket No.:
50-364 Energy to Serve Your World NL-04-2489 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Joseph M. Farley Nuclear Plant - Unit 2 Response to Request for Additional Information Regarding Fall 2002 Steam Generator Inspection Ladies and Gentlemen:
Subsequent to the inservice inspection activities performed at Farley Nuclear Plant (FNP)
Unit 2 during the Fall 2002 maintenance/refueling outage (2R 15), Southern Nuclear Operating Company (SNC) submitted copies of the Insetvice Inspection Summary Report by letter dated January 21, 2003. This report included the results of steam generator tube examinations, as required by Technical Specification 5.6.10. NRC review of these examination results has prompted a Request for Additional Information (RAI). The RAI questions and SNC responses are enclosed.
This letter contains no NRC commitments. If you have any questions, please advise.
Sincerely, 44-Q4&w L. M. Stinson LMS/DWD/sdl
Enclosure:
Response to Request for Additional Information Regarding FNP 2R15 Steam Generator Inspection cc:
Southern Nuclear Operating Company Mr. J. T. Gasser, Executive Vice President Mr. J. R. Johnson, General Manager - Plant Farley RTYPE: CFA04.054; LC# 14191 U. S. Nuclear Regulatorv Commission Dr. W. D. Travers, Regional Administrator Mr. S. E. Peters, NRR Project Manager - Farley Mr. C. A. Patterson, Senior Resident Inspector - Farley A61
Response to Request for Additional Information Regarding FNP 2R15 Steam Generator Inspection NRC Question 1:
Please discuss whether your steam generator has any dents/dings. If your steam generator contains dents/dings, please discuss whether any rotational probe inspections were performed at these locations and the potential for a through-wall or near through-wall flaw to exist at these locations (e.g., are any anomalous dents/ding signals). Please discuss your primary-to-secondary leakage history since installation of the steam generators.
SNC Response:
Farley Unit 2 has the following dents/dings recorded during the 2R15 outage (fall 2002):
SG-A 265 dents, 3 dings SG-B I dent, 0 dings SG-C I dent, 2 dings During the course of the pre-service examination of the Farley Unit 2 replacement steam generators, a large number of dents were reported in SG-A at the 7th tube support plate on the cold leg side. These dents were formed during the heat treatment process of welds in SG-A. All dents/dings in SG-A were tested with a +Point magnetic rotating pancake coil (MRPC) during the pre-service inspection. The dents/dings in SG-B and SG-C (all measuring <5 volts by bobbin coil inspection) were not MRPC tested in the pre-service inspection. No +Point MRPC examinations were performed on dents/dings during the 2R 15 outage since no new dentsldings or signal changes at the existing dents/dings were detected.
Since no new dents/dings or signal changes were detected, the potential for through-wall or near through-wall flaws is remote. No primary-to-secondary leakage has been recorded since steam generator replacement during the 2R14 outage (spring 2001).
NRC Question 2:
General information concerning the design of your replacement steam generators was provided in previous submittals. In order for the staff to better understand the design of your replacement steam generators, please provide the following information: tube manufacturer, tube support thickness, tube pitch and pattern, number of tubes plugged (if any) in each steam generator prior to installation, tubesheet thickness, tubeshect map, and a sketch of the steam generator depicting your tube support plate naming convention. In addition, please clarify what rows of tubes have a centerline radius less than 12-inches (i.e., what rows of tubes had the U-bends stress relieved).
SNC Response:
Tube Manufacturer: Sandvik Tube Support Thickness: Tube Support Plates (I - 7), Quatrefoil, 1.125" Flow Distribution Baffle, Octafoil, 0.750" Tube Pitch and Pattern: 1.225", Square Pitch Number of Tubes Plugged: No plugs in any steam generator Tubesheet Thickness: 21.42" Tubes with a Centerline Radius Less than 12-inches: Rows I - 8 (RI radius= 3.141 "; R8 radius = 11.716")
Tubes with the U-Bends Stress Relieved: Rows 1-8 Page l of3
Response to Request for Additional Information Regarding FNP 2R 15 Steam Generator Inspection Model 54F IIL Tubeshect Map 50 40 30 E
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10 20 30 40 50 60 70 80 90 100 column Tubesheet Map (Hotleg Side) for Westinghouse Model as used at Farley Nuclear Plant 54F Steam Generators Page 2 of 3
Response to Request for Additional Information Regarding FNP 2R15 Steam Generator Inspection MODEL 54F DESIGN SPECIFICS Tube Support Plate Layout for Westinghouse Model 54F Steam Generators as used at Farley Nuclear Plant Page 3 of 3