ML063620409
| ML063620409 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 12/21/2006 |
| From: | Morris G Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| G-RR-1 | |
| Download: ML063620409 (5) | |
Text
Tennessee Valley Authority, Post Office Box 2000, Soddy-Daisy, Tennessee 37384-2000 December 21, 2006 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 Gentlemen:
In the Matter
)Docket No. 50-328 Tennessee Valley Authority
)
SEQUOYAH NUCLEAR PLANT (SQN) - UNIT 2 - PRESSURIZER WELD OVERLAY EXAMINATION RESULTS TO RELIEF REQUEST G-RR-1
References:
1.
Letter from Tennessee Valley Authority to Nuclear Regulatory Commission "Sequoyah Nuclear Plant (SQN) Units 1 and 2 and Watts Bar Nuclear Plant (WVBN) Unit 1 - American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section X1 -
Preemptive Weld Overlays on Alloy 600 Pressurizer Nozzle-To-Pipe Welds and Associated Alternative Repair Techniques - Generic Request for Relief G-RR-1," dated June 16, 2006
- 2. Letter from Tennessee Valley Authority to Nuclear Regulatory Commission "Sequoyah Nuclear Plant (SQN) Units 1 and 2 and Watts Bar Nuclear Plant (WBN) Unit 1 - Preemptive Weld Overlays on Alloy 600 Pressurizer Nozzle-To-Pipe Welds and Associated Alternative Repair Techniques - Generic Request for Relief G-RR TVA Response to NRC'S Request for Additional Information (RAI)
(MD2381, MD2382, MD2383)," dated October 20, 2006
- 3. Letter from Tennessee Valley Authority to Nuclear Regulatory Commission "Sequoyah Nuclear Plant (SQN) Units 1 and 2 -
Preemptive Weld Overlays (PWOL) on Alloy 600 Pressurizer Nozzle-To-Pipe Welds and Associated Alternative Repair Techniques -
Generic Request for Relief G-RR Supplemental Information (TAC NOS. MD2381 & MD2382)," dated November 21, 2006
- 4. Letter from Tennessee Valley Authority to Nuclear Regulatory Commission "Sequoyah Nuclear Plant (SQN) Units 1 and 2 -
Preemptive Weld Overlays (PWOL) on Alloy 600 Pressurizer Nozzle-To-Pipe Welds and Associated Alternative Repair Techniques -
Generic Request for Relief G-RR Supplement 2 (TAC NOS.
MD2381 & MD2382)," dated November 30, 2006 7
L Printed on recycled paper
U.S. Nuclear Regulatory Commission Page 2 December 21, 2006 Reference 1 proposed an alternative (i.e., Relief Request G-RR-11), in accordance with 10 CFR 50.55a(a)(3)(i), to the repair/replacement requirement of the American Society of Mechanical Engineering Boiler and Pressure Vessel Code (ASME Code),Section XI, 2001 Edition, through 2003 Addenda, IWA-4000, for the structural weld overlays on the SQN Unit 2 pressurizer spray, relief, safety and surge nozzle safe ends. References 2, 3 and 4 provide additional information in the support of the proposed alternative.
In References 2 and 3, TVA committed to provide the details of the ultrasonic examination results of the structural weld overlays on the SQN Unit 2 pressurizer spray, relief, safety and surge nozzle safe ends to the NRC within 14 days of the completion of the final ultrasonic examination. After receipt of the Reference 2 submittal, the NRC granted verbal approval of Relief Request G-RR-1 for SQN as stated in Reference 3.
In accordance with Reference 2 and 3, TVA is providing the details of the ultrasonic examination (UT) results of the structural weld overlay on the SQN Unit 2 pressurizer spray, relief, safety, and surge nozzles. The final weld overlay UIT conducted during SQN Unit 2 Cycle 14 refueling outage was completed on December 17, 21006.
The enclosure provides the detailed results of the initial UIT inspections performed on the aforementioned pressurizer nozzles following the weld overlay.
There are no commitments contained in this submittal. If you have any ques tions about this change, please contact me at (423) 843-7170.
Sincerely, Glenn W. Morris Manager, Site Licensing and Industry Affairs Enclosure cc (Enclosure):
Mr. Douglas V. Pickett, Senior Project Manager U.S. Nuclear Regulatory Commission Mail Stop 08G-9a One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2739
Enclosure The attached table provides the detailed results of the initial ultrasonic examination (UT) inspections performed on the pressurizer nozzles following the weld overlay. The following is a summary of these results:
Nozzle Number of Flaw Flaw Indications Assessment Summary Indications SPRAY No Recordable RCF-23A-OL Indications N/A (RCW-24-SE) 1 Laminar
- 1) Laminar - Spot Indication at base-metal/overlay SAFETY interface.
RCF-36A-OL (RCW-26-SE) 1 Axial
- 2) Axial - Spot Indication at base-metal/overlay interface. No through-wall dimension.
SAFETY No Recordable RCF-42A-OL Indications N/A (RCW-25-SE)
SAFETY No Recordable RCF-45A-OL Indications N/A (RCW-28-SE RELIEF No Recordable RCF-24H-OL Indications N/A (RCW-27-SE)
SURGE No Recordable RC-35C-OL Indications N/A (RCW-29-SE As indicated above, the safety nozzle (RCF-36A-OL) was the only nozzle where indications were recorded. The laminar and the axial were spot indications located at the base-metal/overlay interface. These reflectors have no through-wall dimension and do not create an un-inspectable volume of the required PSI/ISI area. There were no repairs required as a result of these examinations.
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ATTACHMENT Safety (RCF-36A-OL) Nozzle - Indication Map Sequoaih Unit 2.-Cucle 14 P~s~~
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