ML11154A037
| ML11154A037 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 06/09/2011 |
| From: | Gratton C Plant Licensing Branch II |
| To: | Krich R Tennessee Valley Authority |
| Gratton C | |
| References | |
| TAC ME5400, 3-ISI-25 | |
| Download: ML11154A037 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 June 9,2011 Mr. R. M. Krich Vice President, Nuclear Licensing Tennessee Valley Authority 3R Lookout Place 1101 Market Street Chattanooga, TN 37402-2801
SUBJECT:
BROWNS FERRY NUCLEAR PLANT, UNIT 3 - REQUEST FOR ADDITIONAL INFORMATION REGARDING RELIEF REQUEST 3-ISI-25 (TAC NO. ME5400)
Dear Mr. Krich:
By letter dated January 21.2011. Tennessee Valley Authority (TVA) submitted a request for relief from weld examination coverage requirements specified in the American Society of Mechanical Engineers Boiler and Pressure Vessel Code,Section XI. Specifically. this request for relief addresses three Residual Heat Removal System full penetration piping welds. two Reactor Water Cleanup System full penetration piping welds and two High Pressure Coolant Injection System full penetration piping welds. Ultrasonic examinations were performed on the accessible areas of these welds to the maximum extent practical for the design configuration of the welds.
Based on our review of your submittal, the U. S. Nuclear Regulatory Commission staff finds that a response to the enclosed request for additional information is needed before we can complete the review.
A draft copy of the enclosed information request was emailed to TVA on May 18,2011. This request was discussed with Mr. Tom Matthews of your staff on June 2.2011, wherein it was agreed that a call clarifying the information request was not needed. TVA agreed to respond to the request for information by July 18, 2011.
If you have any questions, please contact me at (301) 415-1055.
Sincerely. ~~
Christopher Gratton. Senior Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-296
Enclosure:
Request for Additional Information cc w/encl: Distribution via Listserv
REQUEST FOR ADDITIONAL INFORMATION RELIEF REQUEST 3-ISI-25 BROWNS FERRY NUCLEAR PLANT UNIT 3 TENNESSEE VALLEY AUTHORITY DOCKET NO. 50-296 By letter dated January 21,2011, the Tennessee Valley Authority (the licensee) submitted Relief Request 3-ISI-25 requesting relief from the weld examination coverage requirements specified in American SOciety of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section XI, 2001 Edition, as amended by Title 10 of the Code ofFederal Regulations, Section 50.55a (b)(2)(xv)(A)(2), for seven full penetration welds due to access limitations caused by design.
These welds include three Residual Heat Removal (RHR) System full penetration piping welds, two Reactor Water Cleanup (RWCU) System full penetration piping welds, and two High Pressure Coolant Injection System full penetration piping welds.
The U.S. Nuclear Regulatory Commission staff requests that the licensee provide additional information to support the relief from ASME Code Section XI-required volumetric examination of essentially 100 percent of the seven full-penetration welds.
- 1. Please provide a detailed diagram, identifying the materials (stainless steel, carbon steel, nickel alloy) of the base metal, weld, and buttering and show dimensions (nominal inside diameter (ID), outside diameter (OD), and wall thickness) of the flued head to valve configuration for welds DRHR-3-03, DRHR-3-12, and DRHR-3-21, to address questions about the geometry and materials in the residual heat removal system fluid head to valve welds.
- 2. The diagrams provided in the submittal show obstructions for scans performed from the OD surface and appear free of obstructions from the ID surface. Provide a discussion on the feasibility of using different nondestructive examination methods to examine the ID surface for surface-breaking flaws.
- 3. The difficulties in obtaining coverage in several welds seem to be caused by the use of fixed-angle probes with a limited area available for scanning. Provide a discussion of alternative examination methods and techniques, such as phased-array ultrasonic techniques (line scan or raster) that cover many angles, which can be used to obtain greater coverage for welds RWCU-3-001-070, DRHR-3-03, DRHR-3-12, and DRHR-03-21.
- 4. This information request concerns the coverage limitations for welds DRHR-3-03 and DRHR-3-12, based on the drawings and Table 1. Please explain why single-sided coverage and Section 50.55a(b)(2)(xv)(A)(2) are cited as a limitation in Table 1 for DRHR-3-03 and DRHR-3-12, when the drawings show that the calculated coverage for welds DRHR-3-03 and DRHR-3-12 includes examinations from both sides of the weld.
Enclosure
- 2
- 5. Although the Appendix VIII performance demonstration, as administered by the Performance Demonstration Initiative (PDI) program, identifies the coverage from one direction as 50 percent (based on examinations performed from the base metal to the centerline of the weld), the performance demonstration also includes flaws on the other side of the weld centerline. PDI identifies the area on the other side of the weld centerline as "best effort." Were any examinations conducted on these welds that would be deemed by PDI as "best effort"? If so, were any indications found?
June 9,2011 Mr. R. M. Krich Vice President, Nuclear Licensing Tennessee Valley Authority 3R Lookout Place 1101 Market Street Chattanooga, TN 37402-2801
SUBJECT:
BROWNS FERRY NUCLEAR PLANT, UNIT 3 - REQUEST FOR ADDITIONAL INFORMATION REGARDING RELIEF REQUEST 3-151-25 (TAC NO. ME5400)
Dear Mr. Krich:
By letter dated January 21,2011, Tennessee Valley Authority (TVA) submitted a request for relief from weld examination coverage requirements specified in the American Society of Mechanical Engineers Boiler and Pressure Vessel Code,Section XI. Specifically, this request for relief addresses three Residual Heat Removal System full penetration piping welds, two Reactor Water Cleanup System full penetration piping welds and two High Pressure Coolant Injection System full penetration piping welds. Ultrasonic examinations were performed on the accessible areas of these welds to the maximum extent practical for the design configuration of the welds.
Based on our review of your submittal, the U. S. Nuclear Regulatory Commission staff finds that a response to the enclosed request for additional information is needed before we can complete the review.
A draft copy of the enclosed information request was emailedtoTVAonMay18.2011.This request was discussed with Mr. Tom Matthews of your staff on June 2,2011, wherein it was agreed that a call clarifying the information request was not needed. TVA agreed to respond to the request for information by July 18, 2011.
If you have any questions, please contact me at (301) 415-1055.
Sincerely, IRA!
Christopher Gratton, Senior Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor licenSing Office of Nuclear Reactor Regulation Docket No. 50-296
Enclosure:
Request for Additional Information cc w/encl: Distribution via Listserv Distribution:
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