ML071710422

Supplement to Inservice Inspection (ISI) Relief Request No. 36 - Proposed Alternative Associated with the Use of Full-Structural Weld Overlays in the Repair of Dissimilar Metal Welds

ML071710422
Person / Time
Site:	Palo Verde
Issue date:	06/18/2007
From:	Mims D Arizona Public Service Co, Pinnacle West Capital Corp
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
102-05710-DCM/TNW/GAM
Download: ML071710422 (2)

Text

i A A subsidiary of Pinnacle West Capital Corporation Dwight C. Mims Mail Station 7605 Palo Verde Nuclear Vice President Tel. 623-393-5403 P.O. Box 52034 Generating Station Regulatory Affairs and Plant Improvement Fax 623-393-6077 Phoenix, Arizona 85072,2034 102-0571 0-DCM/TNW/GAM June 18, 2007 Attn: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Units 1, 2, and 3 Docket Nos. STN 50-528/529/530 Supplement to Inservice Inspection (ISI) Relief Request No. 36 -

Proposed Alternative Associated With the Use of Full-Structural Weld Overlays in the Repair of Dissimilar Metal Welds By letter no. 102-05641, dated February 8, 2007, Arizona Public Service Company (APS) submitted inservice inspection (ISI) relief request (RR) No. 36 for a proposed alternative associated with the use of full-structural weld overlays in the repair of dissimilar metal welds at PVNGS. In response to a request from the NRC on June 15, 2007, APS is revising paragraph no. 3(c)3 in Enclosure 1 (E-1) Page 11 of the February 8, 2007, submittal as follows (new additional wording is underlined):

The inservice examination acceptance standards of Table IWB-3514-2 shall be applied to planar indications detected in the weld overlay material. If the planar indication is found acceptable per Table IWB-3514-2, the weld overlay will be re-examined in accordance with 3(c)5. If the inservice acceptance criteria of Table IWB-3514-2 are not met, the planar flaw may be evaluated in accordance with IWB-3640, provided that the flaw is not caused by PWSCC. If accepted for continued service the weld overlay will be re-examined in accordance with 3(c)5.

If the flaw is not acceptable for continued service per IWB-3640, then it shall be repaired.

APS agrees to this change because the evaluation allowed by IWB-3640 is for flaws exceeding the acceptance standards of IWB-3514.1, "Allowable Planar Flaws," which does not include flaws caused by Primary Water Stress Corrosion Cracking (PWSCC).

A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway 0 Comanche Peak 0 Diablo Canyon & Palo Verde 0 South Texas Project

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NRC Document Control Desk Supplement to Inservice Inspection Relief Request No. 36 I

Page 2 This letter does not make any commitments to the NRC. If you have any questions, please contact Glenn Michael at (623) 393-5750.

Sincerely, S 2C. 72ý/zý DCM/TNW/GAM/gat cc: B. S. Mallett NRC Region IV Regional Administrator M. T. Markley NRC NRR Project Manager G. G. Wamick NRC Senior Resident Inspector for PVNGS