ML110670168

Correction to Response to Request for Additional Information for the Review of the PVNGS License Renewal Application (Lra), and LRA Amendment No. 30

ML110670168
Person / Time
Site:	Palo Verde
Issue date:	02/25/2011
From:	Hesser J Arizona Public Service Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
102-06324-JHH/GAM
Download: ML110670168 (7)

Text

AA subsidiaryof Pinnacle West CapitalCorporation John H. Hesser Mail Station 7605 Palo Verde Nuclear Vice President Tel: 623-393-5553 PO Box 52034 Generating Station Nuclear Engineering Fax: 623-393-6077 Phoenix, Arizona 85072-2034 102-06324-JHH/GAM February 25, 2011 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, 50-529 and 50-530 Correction to Response to Request for Additional Information for the Review of the PVNGS License Renewal Application (LRA), and LRA Amendment No. 30 By letter no. 102-06285, dated November 23, 2010 (NRC Agencywide Document Access and Management System [ADAMS] Accession No. ML103420101), Arizona Public Service Company (APS) submitted responses to a request for additional information regarding steam generators (SGs) related to the PVNGS license renewal application (LRA). A correction to Response (1) to the RAI is provided in Enclosure 1 to identify the SG divider plate bar material in the Unit 2 SGs as Alloy 600.

Amendment No. 30 of the LRA, provided in Enclosure 2, contains a revision to Commitment No. 61 in LRA Table A4-1 to address the Unit 2 SG divider bar material.

In addition, LRA Amendment No. 30 includes an update to reflect the completion of Commitment No. 60.

Should you need further information regarding this submittal, please contact Glenn Michael, Licensing Engineer for License Renewal, at (623) 393-5750.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on ____-_S'_II (date)

Sinqerely, JHH/RAS/GAM/gat A member of the STARS (Strategic Teaming and Resource Sharing) Alliance W24 Callaway

• Comanche Peak

• Diablo Canyon

• Palo Verde

• San Onofre ° South Texas

• Wolf Creek

ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Correction to Response to Request for Additional Information for the Review of the PVNGS License Renewal Application (LRA), and LRA Amendment No. 30 Page 2

Enclosures:

1. Correction to Response to Request for Additional Information Regarding Steam Generators

2. Palo Verde Nuclear Generating Station License Renewal Application Amendment No. 30 cc: E. E. Collins Jr. NRC Region IV Regional Administrator J. R. Hall NRC NRR Senior Project Manager L. K. Gibson NRC NRR Project Manager M. A. Brown NRC Senior Resident Inspector for PVNGS L. M. Regner NRC License Renewal Project Manager G. A. Pick NRC Region IV (electronic)

ENCLOSURE 1 Correction to Response to Request for Additional Information Regarding Steam Generators

Enclosure 1 Correction to Response to Request for Additional Information Regarding Steam Generators By letter no. 102-06285, dated November 23, 2010 (NRC Agencywide Document Access and Management System [ADAMS] Accession No. ML103420101), Arizona Public Service Company (APS) submitted responses to a request for additional information regarding steam generators (SGs) related to the PVNGS license renewal application (LRA). Response (1) to the RAI stated that the SG primary side components (two divider plates, divider plate bars, patch plates, bolts, and screws) are manufactured from Alloy 690 material. This conclusion was based on the review of Unit 3 as-built documentation and the understanding that the SGs in all units were built to the same specifications. However, it was recently determined from reviewing each unit's SG as-built documentation that the divider plate bars in Unit 2 were made of Alloy 600 as a result of a change report issued during fabrication. As-built documentation has been reviewed to determine if there were other differences in SG primary-side materials between the units, and no other differences were found. However, it was found that the divider bar set screws and the divider patch plate cap screws in the SGs are made of materials other than Alloy 690. The need to correct the RAI response has been entered into the PVNGS corrective action program as Palo Verde Action Request (PVAR) 3588796.

In order to address potential primary water stress corrosion cracking (PWSCC) of the Unit 2 Alloy 600 SG divider plate bars, Commitment No. 61 in LRA Table A4-1 has been expanded, as shown in LRA Amendment No. 30 in Enclosure 2, to include the Unit 2 SG divider plate bars within the scope of the committed analyses, and the exposed portions of the Unit 2 SG divider plate bars within the scope of the committed inspections. The diagram below shows the exposed portions of the divider plate bars that would be accessible for inspection.

Inspection or analysis of the screws is not being included in this commitment because any possible PWSCC that may occur in the screws would not be expected to propagate to the reactor coolant pressure boundary material.

1

ENCLOSURE 2 Palo Verde Nuclear Generating Station License Renewal Application Amendment No. 30 LRA Section Table A4-1, Item 60 Table A4-1, Item 61

Palo Verde Nuclear Generating Station License Renewal Application Amendment No. 30 LRA Table A4-1, License Renewal Commitment No. 60 (deleted text shown in strikethrough and new text underlined):

Item Commitment LRA Section Implementation No. Schedule 60 The reactor coolant sytem transient and cycle traGking procedure Response to Draft RAP I 1i3OLn n

73ST 9RC-2 and- U-FS-AR Sectfion 3.9.1 Will be enRhanced to discuss 4.3- 19 in APR- loller co-rrectve acn-,S thatneed to be taken prior to ASME Section 111 fatigue no. 102 06263, dated dsign; limits being exceeded and to state that corrective acton. ma ,. be Octbo 13,"2010 required for other fatigue related analyses, Guch aS certain AWE-Section Al supplemental fatigue flaw groe4h or cycle dependent fracture mIechanics evaluations that a*e dependent on tho number of Oceu.....es.

of desigR treansAcI31ts.

Completed (RCTSAI 3531679)

Palo Verde Nuclear Generating Station License Renewal Application Amendment No. 30 LRA Table A4-1, License Renewal Commitment No. 61 (new text underlined):

Item Commitment LRA Section Implementation No. "Schedule 61 In response to the NRC staff concern regarding potential failure of the SG Response to Draft RAI If Option (1) is reactor coolant system pressure boundary due to possible PWSCC of SG Regarding Steam selected, it will be divider plate bar welds in all units and the divider plate bars in Unit 2, Generators in APS completed for each APS commits to perform one of the following three resolution options: letter No. 102-06285, SG in each unit

1. Perform an inspection of each Palo Verde Unit 1, 2, and 3 steam dated November 23, during an SG tube generator to assess the condition of the divider plate bar welds in 2010. eddy-current all units, and the exposed portions of the divider plate bars in Unit inspection outage

2. The examination technique(s) will be capable of detecting and between 20 and 25 PWSCC in the divider plate bar welds in all units, and in the calendar years of SG exposed portions of the divider plate bars in Unit 2. Supplemental operation.

OR Response to Draft RAI

2. Perform an analytical evaluation of the steam generator divider Regarding Steam If Option (2) or Option plate bar welds in all units, and the divider plate bars in Unit 2, in Generators in APS (3) is selected, it will order to establish a technical basis which concludes that the SG letter No. 102-06324, be completed prior to reactor coolant system pressure boundary is adequately dated February 25, September 1, 2023.

maintained with the presence of steam generator divider plate bar 2011.

weld cracking.

OR

3. If results of industry and NRC studies and operating experience document that potential failure of the SG reactor coolant system pressure boundary due to PWSCC cracking of SG divider plate bar welds and the divider plate bars in Unit 2 is not a credible concern, this commitment will be revised to reflect that conclusion.

(RCTSAIs 3561775 [U 1], 3561777 [U2], 3561779 [U3])