NG-07-0191, Response to Request for Additional Information on Alternative to ASME Section XI Requirements to Use Code Cases N-504-2 and N-638-1 for Weld Overlay Repairs at the Duane Arnold Energy Center
| ML070660587 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 02/28/2007 |
| From: | Vanmiddlesworth G Florida Power & Light Co, Duane Arnold |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NG-07-0191 | |
| Download: ML070660587 (4) | |
Text
FPL Energy Duane Arnold, LLC 3277 DAEC Road Palo, Iowa 52324 FPLEnergy.
Duane Arnold Energy Center February 28, 2007 NG-07-0191 10 CFR 50.55a(a)(3)(i)
U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Duane Arnold Energy Center Docket No: 50-331 Op. License No: DPR-49 Response to Request for Additional Information on Alternative to ASME Section X1 Requirements to use Code Cases N-504-2 and N-638-1 for Weld Overlay Repairs at the Duane Arnold Energy Center
Reference:
Letter, Gary Van Middlesworth (FPL Energy Duane Arnold) to Document Control Desk (USNRC) - Alternative to ASME Section XI Requirements to use Code Cases N-504-2 and N-638-1 for Weld Overlay Repairs at the Duane Arnold Energy Center, dated February 24, 2006 The referenced letter forwarded the FPL Energy Duane Arnold request for relief to allow use of an alternative to ASME Section XI Requirements to use Code Cases NW504-2 and N-638-1 for weld overlay repairs at the Duane Arnold Energy Center (DAEC). In a conference call with the Staff on February 27, 2007, the NRC requested additional clarifying information concerning the referenced relief request. The Enclosure to this letter contains the requested information.
This letter contains no new commitments and no revisions to existing commitments.
Questions regarding this matter should be directed to Steve Catron, Licensing Manager, at (319) 851-7234.
Sincerely yours, Gary Van Middlesworth Site Vice President, Duane Arnold Energy Center FPL Energy Duane Arnold
NGr-07-0191 February 28, 2007 Page 2 of 2 Enclosure cc:
Administrator, Region III, USNRC Project Manager, DAEC, USNRC Resident Inspector, DAEC, USNRC
Enclosure to NG-07-0191 Response to Request for Additional Information on Alternative to ASME Section Xl Requirements to use Code Cases N-504-2 and N-638-1 for Weld Overlay Repairs at the Duane Arnold Energy Center Request #1 FPL Energy Duane Arnold credits a PQR for the qualification of the WSI weld overlay procedure. What material was used for that test?
FPL Energy Duane Arnold Response:
There are a total of three PQRs that support the weld procedure:
- 1) PQR-03-03-T-803 used a base material of SA-533, Grade B Classi;
- 2) PQR-43-43-T-001 used SB-1 68 to SB-168; and,
- 3) PQR-03-43-T-001 used SA-533, Type A Class 2 to SB-168.
Request #2 FPL Energy Duane Arnold requested up to 500 square inches (per Code Case), but NRC has not approved any request over 300 square inches. The referenced relief request anticipated approximately 180 square inches of coverage. What is the maximum expected weld overlay coverage?
FPL Energy Duane Arnold Response:
The weld overlay will not exceed 260 square inches on the low alloy nozzle (Area under the segment labeled "B" in the Figure on page 4 of 14 of the relief request (Reference 1)).
Request #3 What is the expected distance of the pre-service UT inspection on the nozzle side from the edge of the new weld? FPL Energy Duane Arnold provided verbal discussion during the conference call to indicate that it will depend on the transducer size and how far it will give data before it loses contact. NRC would like FPL Energy Duane Arnold to provide an estimate.
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Enclosure to NG-07-0191 FPL Energy Duane Arnold Response:
Based upon an in-the-field measurement of the actual transducer, FPL Energy Duane Arnold has estimated the limitation of the UT exams on the nozzle side in the four orthogonal directions: in the circumferential direction, for scanning clockwise and counterclockwise, the limitation distance is 0.4 inch; in the direction scanning toward the nozzle the limitation distance is 0.4 inch; and when scanning away from the nozzle taper, the limitation distance is 0.6 inch.
Reference:
Letter, Gary Van Middlesworth (FPL Energy Duane Arnold) to Document Control Desk (USNRC) - Alternative to ASME Section XI Requirements to use Code Cases N-504-2 and N-638-1 for Weld Overlay Repairs at the Duane Arnold Energy Center, dated February 24, 2004.
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