ML102990530

Summary of Telephone Conference Call Held on October 22, 2010, Btw the USNRC and Arizona Public Service Company, Concerning D-RAI Pertaining to the Palo Verde Nuclear Generating Station, Units 1, 2, and 3, LRA

ML102990530
Person / Time
Site:	Palo Verde
Issue date:	11/16/2010
From:	Lisa Regner License Renewal Projects Branch 2
To:	Arizona Public Service Co
Regner L M, NRR/DLR, 415-1906
References
Download: ML102990530 (6)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-6001 November 16, 2010 LICENSEE: Arizona Public Service Company FACILITY: Palo Verde Nuclear Generating Station, Units 1,2, and 3

SUMMARY

OF TELEPHONE CONFERENCE CALLS HELD ON OCTOBER 22 AND NOVEMBER 3,2010, BETWEEN THE U.S. NUCLEAR REGULATORY COMMISSION AND ARIZONA PUBLIC SERVICE COMPANY, CONCERNING DRAFT REQUEST FOR ADDITIONAL INFORMATION PERTAINING TO THE PALO VERDE NUCLEAR GENERATING STATION, UNITS 1, 2, AND 3, LICENSE RENEWAL APPLICATION The U.S. Nuclear Regulatory Commission (the staff) and representatives of Arizona Public Service Company (the applicant) held telephone conference calls on October 22 and November 3, 2010, to discuss and clarify the staff's draft request for additional information (RAI) concerning the Palo Verde Nuclear Generating Station, Units 1,2, and 3, license renewal application. The telephone conference call was useful in clarifying the intent of the staff's draft RAI. provides a listing of the participants and Enclosure 2 contains a listing of the draft RAI discussed with the applicant, including a brief description on the status of the items.

The applicant had an opportunity to comment on this summary.

ner, Sr. Project Manager Projects Branch 2 Division of License Renewal Office of Nuclear Reactor Regulation Docket Nos. 50-528, 50-529, and 50-530

Enclosures:

As stated cc w/encls: Distribution via Listserv

TELEPHONE CONFERENCE CALL PALO VERDE NUCLEAR GENERATING STATION, UNITS 1,2, AND 3 LICENSE RENEWAL APPLICATION LIST OF PARTICIPANTS OCTOBER 22, 2010 PARTICIPANTS AFFILIATIONS Lisa Regner U.S. Nuclear Regulatory Commission (NRC)

Allen Hiser NRC Rachel Vaucher NRC Ken Karwoski NRC Andrew Johnson NRC Angela Krainik Arizona Public Service Company (APS)

Edison Fernandez APS Douglas Hansen APS Warren Leaverton APS Randal Boyd APS Eric Blocher Strategic Teaming and Resource Sharing (STARS) Alliance LIST OF PARTICIPANTS NOVEMBER 3,2010 PARTICIPANTS AFFILIATIONS Lisa Regner NRC Allen Hiser NRC RachelVaucher NRC Ken Karwoski NRC Andrew Johnson NRC Angela Krainik APS Glenn Michael APS Eric Blocher STARS ENCLOSURE 1

DRAFT REQUESTS FOR ADDITIONAL INFORMATION PALO VERDE NUCLEAR GENERATING STATION, UNITS 1, 2, AND 3 LICENSE RENEWAL APPLICATION OCTOBER 22, 2010 NOVEMBER 3, 2010 The U.S. Nuclear Regulatory Commission (the staff) and representatives of Arizona Public Service Company (the applicant) held telephone conference calls on October 22 and November 3, 2010, to discuss and clarify the following draft request for additional information (RAI) concerning the Palo Verde Nuclear Generating Station (Palo Verde), Units 1, 2, and 3, license renewal application (LRA).

1. The Updated Final Safety Analysis Report (UFSAR), Section 1.2.3.3, states that a vertical divider plate separates the inlet and outlet plenums in the lower head of the steam generators (SGs), but no information about the materials of the divider plate assembly, nor its junction to the lower head and to the tubesheet was found in the UFSAR nor the LRA. Clarify how the divider plate is assembled to the lower head and to the tubesheet and what are the materials of this divider plate and potential associated welds? If this information is in the UFSAR, please specify its location.

2. Regarding LRA item 3.1.1-35, the applicant states that it's not applicable because they have recirculating SGs and the Generic Aging Lessons Learned (GALL) Report item is for once-through SGs. However, this aging effect is applicable also for recirculating SGs tube-to-tubesheet welds, when SG tubes are Alloy 690TT (which is the case for Palo Verde) and the tubesheet cladding is Alloy 600. In such a configuration, the weld could have insufficient chromium content to prevent primary water stress corrosion cracking (PWSCC). If it is Alloy 600, describe how PWSCC is managed in the tube-to-tubesheet welds.

3. LRA Table 3.1.2-4 does not include an item addressing GALL item IV.D1-17, which corresponds to ligament cracking due to corrosion in steel tube support plates.

However, in LRA Table 3.1.2-4, the applicant addresses GALL item IV.D1-19, which corresponds to SG tube denting due to corrosion of carbon steel tube support plate. In LRA Section 82.1.8, the applicant also states that the tube support system is Similar to the original design, and like the original design is fabricated from 409 ferritic stainless steel. Explain this apparent inconsistency.

Discussion:

The staff indicated that if there is nothing on the docket that indicates that the material susceptible to PWSCC is isolated from the primary coolant, such information would need to be submitted formally by the applicant.

Following discussion, the staff modified the second question as follows:

2. Regarding LRA item 3.1.1-35, the applicant states that it's not applicable because they have reCirculating SGs and the GALL Report item is for once-through SGs. However, this aging effect is applicable also for recirculating SGs tube-to-tubesheet welds with ENCLOSURE 2

-2 tubesheet cladding of Alloy 600 and SG tubes of Alloy 690TT (which is the case for Palo Verde). In such a configuration, the weld may have insufficient chromium content to prevent PWSCC. If the tubesheet cladding is Alloy 600, describe how PWSCC is managed for aging in the tube-to-tubesheet welds.

The applicant stated that it understood the questions and would respond to the staff's concerns.

November 16, 2010 LICENSEE: Arizona Public Service Company FACILITY: Palo Verde Nuclear Generating Station, Units 1, 2, and 3

SUMMARY

OF TELEPHONE CONFERENCE CALLS HELD ON OCTOBER 22 AND NOVEMBER 3,2010, BETWEEN THE U.S. NUCLEAR REGULATORY COMMISSION AND ARIZONA PUBLIC SERVICE COMPANY, CONCERNING DRAFT REQUEST FOR ADDITIONAL INFORMATION PERTAINING TO THE PALO VERDE NUCLEAR GENERATING STATION, UNITS 1, 2, AND 3, LICENSE RENEWAL APPLICATION The U.S. Nuclear Regulatory Commission (the staff) and representatives of Arizona Public Service Company (the applicant) held telephone conference calls on October 22 and November 3, 2010, to discuss and clarify the staff's draft request for additional information (RAI) concerning the Palo Verde Nuclear Generating Station, Units 1, 2, and 3, license renewal application. The telephone conference call was useful in clarifying the intent of the staff's draft RAI. provides a listing of the participants and Enclosure 2 contains a listing of the draft RAI discussed with the applicant, including a brief description on the status of the items.

The applicant had an opportunity to comment on this summary.

IRA!

Lisa M. Regner, Sr. Project Manager Projects Branch 2 Division of License Renewal Office of Nuclear Reactor Regulation Docket Nos. 50-528, 50-529, and 50-530

Enclosures:

As stated cc w/encls: Distribution via Listserv DISTRIBUTION:

See next page ADAMS Accession No*.. ML102990530 *concurrence via e-mail OFFICE PM:RPB2:DLR LA:DLR BC:RPB2:DLR PM:RPB2:DLR NAME LRegner YEdmonds* DWrona LRegner DATE 11/15/10 11/04/10 11/15/10 11/16/10 OFFICIAL RECORD COpy

Memorandum to Arizona Public Service Company from L. Regner dated November 16, 2010

SUMMARY

OF TELEPHONE CONFERENCE CALLS HELD ON OCTOBER 22, AND NOVEMBER 3,2010, BETWEEN THE U.S. NUCLEAR REGULATORY COMMISSION AND ARIZONA PUBLIC SERVICE COMPANY, CONCERNING DRAFT REQUEST FOR ADDITIONAL INFORMATION PERTAINING TO THE PALO VERDE NUCLEAR GENERATING STATION, UNITS 1, 2, AND 3, LICENSE RENEWAL APPLICATION DISTRIBUTION:

HARDCOPY:

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