ML102660067

9/22/10 Summary of Teleconference Held Between U.S. NRC and Arizona Public Service Company, Concerning Draft Request for Additional Information Pertaining to the Palo Verde Nuclear Generating Station, Units 1, 2, and 3, LRA

ML102660067
Person / Time
Site:	Palo Verde
Issue date:	10/15/2010
From:	Lisa Regner License Renewal Projects Branch 2
To:	Arizona Public Service Co
Regner L M, NRR/DLR, 415-1906
References
Download: ML102660067 (6)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON. D.C. 20555-0001 October 15, 2010 LICENSEE: Arizona Public Service Company FACILITY: Palo Verde Nuclear Generating Station, Units 1, 2, and 3

SUMMARY

OF TELEPHONE CONFERENCE CALL HELD ON SEPTEMBER 22,2010, 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 a telephone conference call on September 22,2010, 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 questions discussed with the applicant, including a brief description on the status of the items.

The applicant had an opportunity to comment on this isa 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

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

Allen Hiser NRC James Medoff NRC OnYee NRC Ching Ng NRC Angela Krainik Arizona Public Service Company (APS)

Glenn Michael APS George Pilicy APS Winston Borrero APS Eugene Montgomery APS Doug Berg APS Mark Radspinner APS Rex Meeden APS Eric Blocher Strategic Teaming and Resource Sharing (STARS) Alliance Don Stevens STARS Richard Schaller Utilities Service Alliance David Gerber Structural Integrity Associates (SIA)

Curt Carney SIA ENCLOSURE 1

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

DRAFT RAI 4.3-19

Background:

In lRA Section 4.7.4, the applicant dispositioned American Society of Mechanical Engineers (ASME) Code Section XI supplemental fatigue flaw growth or cycle-dependent fracture mechanics evaluations in accordance with Title 10 of the Code of Federal Regulations (10 CFR)

Part 54.21 (c)(1 )(iii). The applicant proposed to use the cycle counting activities from its Metal Fatigue of Reactor Coolant Pressure Boundary Program to manage the effects of aging and verify the continued validity of these ASME Code Section XI analyses during the period of extended operation.

Issue:

The staff noted that the applicants proposal to use cycle counting activities to verify the continued validity of these ASME Code Section XI analyses may be beyond the applicants current licensing basis (ClB).

The staff noted that Technical SpeCifications (TS) 5.5.5 and Updated Final Safety Analysis Report (UFSAR), Section 3.9.1.1 discuss cycle tracking and counting against design limits and design calculations, but does not appear to discuss design transient tracking and counting for ASIVIE Code Section XI supplement fatigue flaw growth or cycle dependent fracture mechanics evaluations.

Per TS 5.5.5 and UFSAR Section 3.9.1.1, cyclic and transient occurrences are tracked to ensure that components are maintained within the design limits. However, the applicants cycle counting procedure does not discuss the types of analyses this requirement is applicable to or the action limits and corrective actions that may be taken for these fatigue related or fracture mechanics evaluations. The staff noted that these corrective actions should be specified in the applicants procedures and the action limits and corrective actions should be associated with the specific type of analysis.

Request:

Clarify how design basis transient cycle tracking and counting activities are accounted for in the ClB for these types ASME Section XI supplemental fatigue flaw growth or cycle-dependent fracture mechanics evaluations.

Justify the use of design basis transient cycle tracking and counting activities as the basis to disposition the ASME Code Section XI analyses if the scope of the applicanfs ClB does not include this activity.

ENCLOSURE 2

2 Discussion: The applicant stated that it understood the question and will respond.

DRAFT Follow-up RAI 4.3-2

Background:

In its response to RAI 4.3-2, dated June 29, 2010, the applicant stated that there is a factor of five difference between the cumulative usage factors (CUFs) reported for the instrument nozzles at Unit 1 from those that are reported for the corresponding nozzles at Units 2 and 3 because of modeling and analysis methods and assumptions. The applicant stated that the differences include:

• the Unit 1 analysis used a more-conservative treatment of vortex shedding

• some model differences resulting in a slightly-different limiting location

• arithmetic instead of vector load addition at the limiting Unit 1 location The applicant also stated the vortex shedding difference produced a larger number of assumed vortex sheddill9 load cycles for Unit 1, which was a significant factor in the difference.

Furthermore, the stress ranges in some cases were slightly lower in the analyses for Units 2 and 3 as compared to Unit 1, and a small reduction in stress range yields a significant reduction in CUF.

Issue:

The details associated with the differences that were described by the applicant in its response are unclear. Specifically, it is unclear if vortex shedding is accounted for in the fatigue analysis for Units 2 and 3 and why the Unit 1 analysis treat vortex shedding so conservatively. It is also not clear to the staff why the stress ranges were slightly lower for the analyses for Units 2 and 3 as compared to Unit 1.

Request:

a) Clarify which transients are affected by the vortex shedding effect.

b) Clarify if the Unit 2 and 3 analyses account for vortex shedding:

• If yes, justify why it was treated less conservatively when compared to the Unit 1 fatigue analysis.

• If not, justify why it does not need to be accounted for in the fatigue analyses.

c) Clarify and justify why the stress ranges were slightly lower for the analyses for Units 2 and 3 as compared to Unit 1.

Discussion: The applicant stated that it understood the question and will respond.

October 15, 2010 LICENSEE: Arizona Public Service Company FACILITY: Palo Verde Nuclear Generating Station, Units 1, 2, and 3

SUMMARY

OF TELEPHONE CONFERENCE CALL HELD ON SEPTEMBER 22,2010, 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 a telephone conference call on September 22,2010, 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 questions 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'.. ML102660067 OFFICE LA:RPOB:DLR PM:RPB2:DLR BC:RPB2:DLR PM:RPB2:DLR NAME IKing (YEdmonds LRegner DWrona LRegner for) (Signature) 9/28/10 10/5/10 10/15/10 10/15/10 DATE OFFICIAL RECORD COpy

Memo to Arizona Public Service Company from Lisa M. Regner dated October 15, 2010

SUMMARY

OF TELEPHONE CONFERENCE CALL HELD ON SEPTEMBER 22,2010, 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:

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