ML101760027

Summary of Telecon Calls Held on May 5, May 19, and June 16, 2010 Between the USNRC and Arizona Public Service Company, Concerning D-RAI Pertaining to the Palo Verde Nuclear Generating Station, Units 1, 2, and 3, License Renewal Application

ML101760027
Person / Time
Site:	Palo Verde
Issue date:	07/19/2010
From:	Lisa Regner License Renewal Projects Branch 2
To:	Edington R Arizona Public Service Co
Regner L M, NRR/DLR, 415-1906
References
Download: ML101760027 (11)

Text

July 19, 2010 LICENSEE: Arizona Public Service Company FACILITY: Palo Verde Nuclear Generating Station, Units 1, 2, and 3

SUMMARY

OF TELEPHONE CONFERENCE CALLS HELD 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 May 5 and 19, 2010, and June 16, 2010, to discuss and clarify the staffs draft requests for additional information (RAIs) 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 staffs draft RAIs. provides a listing of the participants. Enclosures 2 and 3 contain a listing of the draft RAIs discussed with the applicant, including a brief description on the status of the items.

The applicant had an opportunity to comment on this summary.

/RA/

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: See next page

ML101760027 OFFICE PM:RPB2:DLR LA:RPOB:DLR BC:RPB2:DLR PM:RPB2:DLR NAME LRegner IKing DWrona LRegner DATE 07/15/10 06/30/10 07/16/10 07/19/10

Memorandum to Arizona Public Service Company from Lisa M. Regner dated July 19, 2010

SUMMARY

OF TELEPHONE CONFERENCE CALLS HELD 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:

HARD COPY:

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TELEPHONE CONFERENCE CALL PALO VERDE NUCLEAR GENERATING STATION, UNITS 1, 2, AND 3 LICENSE RENEWAL APPLICATION LIST OF PARTICIPANTS MAY 5, 2010, MAY 19, 2010, AND JUNE 16, 2010 PARTICIPANTS AFFILIATIONS Lisa Regner U.S. Nuclear Regulatory Commission (NRC)

John Tsao NRC Angela Krainik Arizona Public Service Company (APS)

Glenn Michael APS Eugene Montgomery* APS Doug Berg* APS Winston Borreo** APS Alfred Meeden*** APS Eric Blocher* Strategic Teaming and Resource Sharing (STARS) Alliance Donald Stevens STARS

• Participated only on May 5 and May 19 calls

• • Participated only on May 19 and June 16 calls

• • • Participated only on June 16 call ENCLOSURE 1

DRAFT REQUESTS FOR ADDITIONAL INFORMATION PALO VERDE NUCLEAR GENERATING STATION, UNITS 1, 2, AND 3 LICENSE RENEWAL APPLICATION May 5, 2010 May 19, 2010 June 16, 2010 The U.S. Nuclear Regulatory Commission (the staff) and representatives of Arizona Public Service Company (the applicant or APS) held telephone conference calls on May 5, and 19, 2010, and June 16, 2010, to discuss and clarify the following draft request for additional information (RAI) concerning the Palo Verde Nuclear Generating Station (PVNGS), Units 1, 2, and 3, license renewal application (LRA).

Draft Follow-Up RAI Responses APS Response to RAI 4.3.2.4-1(a)

(1) Provide Combustion Engineering Infobulletin 88-09 or describe in detail the contents of the infobulletin. (2) APS stated that Disposition of these TLAAs for the period of extended operation, therefore, on 10 CFR 54.21(c)(1)(iii) aging management using the enhanced fatigue management program. Also, in various responses to RAI questions for Sections 4.3.2.4, 4.3.2.7, 4.3.2.9, and 4.3.2.15, the applicant used various phrases such as the fatigue management program, enhanced fatigue management program, and metal fatigue aging management program. Confirm that these programs refer to only AMP B3.1, Metal Fatigue of Reactor Coolant Pressure Boundary.

APS Response to RAI 4.3.2.4-2(b)

Discuss the inspection plan for the two flaws detected in the pressurizer support skirt forging weld from present to the end of 60 years. Discuss the allowable flaw size before the support skirt forging weld needs to be repaired and how the allowable flaw size was derived. Cite the reference of the allowable flaw size derivation.

APS Response to RAI 4.3.2.4-3(a)

The applicant stated that the original structures, systems, and components (SSC) design specifications bound the new operating conditions associated with power uprate and steam generator replacement. However, it appears that the assessment was related to the design life of 40 years. Discuss the impact of the power uprate and steam generator replacement on the pressurizer design, operation and structural integrity through the period of extended operation.

APS Response to RAI 4.3.2.4-4 The applicant stated that the fatigue cumulative usage factor (CUF) will not exceed the code limit of 1.0 so long as the number of applied load cycles does not exceed the number specified by the design specification for the pressurizer surge nozzle, and used in the CUF analysis. The applicant stated that the CUF for the surge nozzle at the end of 60-year period is 1.44. This means that the fatigue CUF will most likely to exceed the code limit of 1.0 before the current license. (1) Confirm that the aging management program is the AMP B3.1 Metal Fatigue of Reactor Coolant Pressure Boundary to ensure that the code limit of 1.0 will not be exceeded.

ENCLOSURE 2

(2) Describe how AMP B3.1 monitors the CUF to ensure that it will not exceed 1.0. (3) Describe actions will be taken before the CUF approaches 1.0.

APS Response to RAI 4.3.2.4-10(a)

The applicant stated that the flaw growth analyses for the pressurizer overlaid surge and spray nozzles were based on 60 years. Therefore, the flaw evaluations are not a TLAA. It appears that if a flaw evaluation or fatigue calculation is not a TLAA, AMP B3.1 Metal Fatigue of Reactor Coolant Pressure Boundary will not be used to monitor the component. The NRC staff believes that even though the flaw growth calculations for the pressurizer overlaid nozzles were based on 60 years, the applicant still needs to verify and confirm that the transient cycles used in the flaw evaluation bound the actual transient cycles. The NRC staff believes that the transient cycle verification needs to be performed under AMP B3.1, Metal Fatigue of Reactor Coolant Pressure Boundary. Justify why AMP B3.1 is not implemented on the pressurizer overlaid nozzles or any pressurizer components that are identified as not a TLAA in Table 4.3-7 of the license renewal application.

APS Response to RAI 4.3.2.7-2 The applicant stated that the stress-based fatigue calculation for the chemical and volume control system charging nozzle has not yet been performed. The applicant stated that the stress-based fatigue monitoring will be implemented at least two years before the period of extended operation. Confirm that the stress-based fatigue calculation will be completed and submitted for NRC review and approval at least two years before the beginning of the period of extended operation.

APS Response to RAI 4.3.2.7-6(a)

The applicant stated that The analysis and testing of the redesigned thermowell determined that the new design was not susceptible to this failure mechanism. Describe in detail or provide the analysis and testing reports of the new thermowells so that the new thermowells will not be susceptible to high cycle fatigue.

APS Response to RAI 4.3.2.7-6(b)

The applicant stated that This determination did not consider the plant life; therefore, the evaluation for high-cycle fatigue is not a TLAA in accordance with 10 CFR 54.3(a) Criterion 3. (1) Please explain the above statement. (2) 10 CFR 54.3(a),

Criterion 3, states that TLAA are those licensee calculations and analyses that Involve time limited assumptions defined by the current operating terms, for example 40 years. Explain how Criterion 3 is applicable to the new thermowells such that the new thermowells do not require a TLAA. (3) Explain how the structural integrity of the new thermowells will be maintained and monitored to the end of 60 years.

APS Response to RAI 4.3.2.9-1(a)

The applicant stated that Combustion Engineering Owners Group (CEOG) calculation, MSIC-ME-C-115, calculated a CUF of 0.778 and 1.65 for the pressurizer surge line elbow.

Combustion Engineerings report CEN-387-P calculated a CUF of 0.937 at the same surge line elbow. APS Response to RAI 4.3.2.9-1(c) mentioned a CUF of 1.9396 for the same surge line elbow based on an APS re-evaluation using a simplified elastic-plastic analysis. (1) Discuss in detail why three separate calculations were performed for the same surge line elbow, especially the APS re-evaluation. Provide issuance dates of the three assessments. (2) The applicant

stated that a CUF of 0.937 is the analysis of record result because the calculation for the CUF of 0.937 is more precise than the calculation for the CUFs of 0.778 and 1.65. However, the staff believes that the CUF of 1.65 and 1.9396 are more conservative than a CUF of 0.937. Discuss why the analysis of record is not based on the CUF of 1.65 or 1.9396.

APS Response to RAI 4.3.2.9-1(c)

The applicant stated that fatigue at the surge line elbow will be managed by stress-based fatigue monitoring and the action limits for the surge line elbow will depend on calculated actual fatigue usage, not on a 40-year or 60-year value. AMP B3.1, Metal Fatigue of Reactor Coolant Pressure Boundary, describes the cycle count action limit, cumulative fatigue usage action limit, and associated corrective actions (pages B-116 and B-117 of the Palo Verde LRA). However, it is not clear whether the description of the cycle count activities is the same as the activities for the stress-based fatigue monitoring. Discuss how stress-based fatigue monitoring will be conducted for the surge line elbow, including the action limits and describe the actions.

APS Response to RAI 4.3.2.9-2(b)

The applicant stated that The current ASME Section XI program does not extend through the sixth inservice inspection interval. Explain why the ASME Section XI program does not extend through the sixth inservice inspection interval.

Discussion: By letter dated March 1, 2010, the applicant provided a sufficient response to the staffs RAIs. However, the staff provided the above follow-up questions to the applicant for a clarification discussion.

On May 5, 2010, the applicant gave clarification on Section 4.3.2.9.

On May 19, 2010, and June 16, 2010, the applicant provided additional clarification for the reviewer to complete the Safety Evaluation Report.

All information required by the staff is in the LRA or the RAI responses provided by the applicant.

DRAFT REQUESTS FOR ADDITIONAL INFORMATION PALO VERDE NUCLEAR GENERATING STATION, UNITS 1, 2, AND 3 LICENSE RENEWAL APPLICATION JUNE 16, 2010 The U.S. Nuclear Regulatory Commission (the staff) and representatives of Arizona Public Service Company (the applicant or APS) held a telephone conference call on June 16, 2010, to discuss and clarify the following draft request for additional information (D-RAI) concerning the Palo Verde Nuclear Generating Station (PVNGS), Units 1, 2, and 3, license renewal application (LRA).

Staff comments on APS Response to RAI Questions dated March 1, 2010, and on LRA Section 4.3.

The staff requests clarification from the applicant regarding its response to RAI questions, dated March 1, 2010, as follows:

1) LRA Page 4.3-57, 2nd paragraph to the last paragraph, states Three methods of repairs have been used, full nozzle, welded plugs, and half-nozzle, also known as three-quarter nozzle repairs for the inservice RTDs. Is the half nozzle repair the same as the three-quarter nozzle repair? In its response to RAI 4.3.2.7-4, the applicant provided a table with all small bore nozzle repairs. In that table, the applicant specified half nozzle repair and three-quarter nozzle repair. If both repairs are the same, why did the applicant specify half nozzle repair and three-quarter nozzle repair as if they are not the same repair?

2) In RAI 4.3.2.7-9, the staff asked the applicant to explain why fracture mechanics analyses of the hot leg surge and shutdown cooling nozzles overlaid by the weld repair are not a TLAA as stated on LRA page 4.3-61. By letter dated March 1, 2010, in response to RAI 4.3.2.7-9, the applicant stated that the fatigue crack growth analyses to support the hot leg surge and shutdown cooling nozzle weld overlay repairs calculate the crack propagation in order to demonstrate that a postulated crack will not exceed the acceptance criterion of the analysis during the inspection interval. The inspection interval is less than the plant life; therefore, the fatigue crack growth analyses are not TLAAs, in accordance with 10 CFR 54.3(a)

Criterion 3. The applicant stated further that the fatigue crack growth analyses of the weld overlay of the hot leg surge line and shutdown cooling line nozzle is not TLAA because the postulated flaw is calculated for the inspection interval.

The staff agrees that the fatigue crack growth analyses are not TLAA when the nozzle is inspected once every 10 year inspection interval. However, it is not clear whether the surge line and shutdown cooling line nozzles will be inspected once every 10 year interval. If the nozzle is not inspected every 10 years then the fatigue crack growth analyses are TLAA.

Therefore, to support its position that this is not a TLAA, the applicant needs to reference the NRC-approved relief request (with specific pages in the relief request) that requires inspection of the overlaid surge line and shutdown cooling line nozzles every 10 years or provide commitment in the LRA that these overlaid nozzles will be inspected every 10 years during the period of extended operation.

3) Section 4.7.4 Page 4.7-7 states that:

On March 25, 2005, PVNGS submitted APS letter 102-05237 to the NRC. This request uses CN-CI-02-71 and WCAP-15973-P in support of a request for exemption from the flaw removal and successive inspection requirements of ASME XI (1992) sections IWA-3300 and IWB-2420, for the alternative half-nozzle method used for the 10 PVNGS Unit 2 small bore, hot leg nozzles to be repaired during the Spring 2005 refueling outage. WCAP-15973-P calculated corrosion rates of 1.53 mils per year (mpy) for Alloy 600 nozzles. In response to the conditions of the final safety evaluation for the Westinghouse topical report, APS calculated that a limiting corrosion rate of 1.377 mpy for Unit 3 would not exceed the allowable diameter until 2058, 60 years after the repair and 10 years after the end of the period of extended operation. This calculation is therefore not a TLAA, and is valid for the period of extended operation.

The above paragraph discussed that Unit 3 is not a TLAA.

Questions:

Is the corrosion analysis (per the corrosion rates were discussed in the above paragraph) for Unit 2 a TLAA? Is the corrosion analysis for Unit 1 a TLAA? Why were Unit 1 nozzles not discussed in this paragraph?

4) In response to RAI 4.7.4-2, the applicant provided the following listing:

8 Unit 2 nozzles repaired in 1991 via a full nozzle repair (not covered under Relief Request 31) 10 Unit 2 nozzles repaired in 2005 under Relief Request 31, Revision 0 9 Unit 2 nozzles repaired under Relief Request 31, Revision 1 27 Unit 1 nozzles repaired under Relief Request 31, Revision 1 27 Unit 3 nozzles repaired under Relief Request 31, Revision 1 81 Total Relief Request 31, Revision 0, addressed 10 nozzles replaced in Unit 2 during the spring of 2005. Relief Request 31, Revision 1, added the following previously-repaired PVNGS Alloy 600 small-bore hot leg nozzles as follows:

Unit 1 - 27 nozzles, Unit 2 - 9 nozzles, and Unit 3 - 27 nozzles Total - 63 nozzles.

The last 63 nozzles repaired under Relief Request 31, Revision 1 were replaced under the Palo Verde Alloy 600 replacement program, from approximately October 1999 to April 2003.

In response to RAI 4.3.2.7-4 the applicant also provided a table of all small bore nozzles at each unit.

Question:

In the table above (the 81 nozzle table) for Unit 2, confirm that the 10 nozzles are the 10 in service RTD which were repaired by three quarter nozzle repair covered under Relief Request 31, Revision 0, as shown in the table in the response to RAI 4.3.2.7-4. Confirm that, for Unit 2, the above 9 nozzles consist of 1 pressure and sampling nozzle which was repaired by the half nozzle repair and 8 spare RTD which were repaired by welded plugs and were covered under Relief Request 31, Revision 1, as shown in the table in the response to RAI 4.3.2.7-4.

The applicant stated that the last 63 nozzles repaired under Relief Request 31, Revision 1 were replaced under the Palo Verde Alloy 600 replacement program, from approximately October 1999 to April 2003. What does it mean by 63 repaired nozzles that were replaced? If a nozzle is repaired why would it be replaced? Do you mean a nozzle was repaired initially and then later was replaced with a completely new nozzle or with a different repair method? Do you mean a nozzle was repaired by MNSA initially and then was replaced with the half nozzle repair?

Provide the relief request number and the date of submittal for the 8 small bore nozzles in Unit 2 that were repaired by full nozzle repair method and those were not covered under relief request #31.

5) In response to RAI 4.3.2.4-6, the applicant stated that the fatigue analyses of the pressurizer heater sleeve half nozzle repairs were evaluated for 60 years. Therefore these fatigue analyses are not TLAA. See LRA Table 4.3-7, items 16, 17, and 18. The staff agrees that if a fatigue analysis is performed for 60 years then the fatigue analysis is not TLAA. However, how can the transient cycles used in these 60-year fatigue analyses be monitored to ensure that they bound the actual cycles? This question also applies to item 21 in LRA Table 4.3-7 as part of the applicants response to RAI 4.3.2.4-10.

This question also applies to the applicants response to RAI 4.3.2.15-1 in which the applicant stated that the fatigue calculation was performed to many times over 40 years for the LBB-approved primary loop piping. However, how can the transient cycles used in the LBB fatigue analysis be monitored to ensure that they bound the actual cycles?

Discussion: The above items were discussed with the applicant, which resulted in all issues being resolved.

Palo Verde Nuclear Generating Station, Units 1, 2, and 3 cc:

Mr. Steve Olea Mr. John C. Taylor, Director, Nuclear Arizona Corporation Commission Generation 1200 W. Washington Street El Paso Electric Company Phoenix, AZ 85007 340 E. Palm Lane, Suite 310 Phoenix, AZ 85004 Mr. Douglas Kent Porter, Senior Counsel Southern California Edison Company Mr. James Ray Law Department, Generation Resources Public Service Company of New Mexico P.O. Box 800 2401 Aztec NE, MS Z110 Rosemead, CA 91770 Albuquerque, NM 87107-4224 Senior Resident Inspector Mr. Geoffrey M. Cook U.S. Nuclear Regulatory Commission Southern California Edison Company P.O. Box 40 5000 Pacific Coast Highway, Bldg. D21 Buckeye, AZ 85326 San Clemente, CA 92672 Regional Administrator, Region IV Mr. Robert Henry U.S. Nuclear Regulatory Commission Salt River Project 612 E. Lamar Blvd., Suite 400 6504 E. Thomas Road Arlington, TX 76011-4125 Scottsdale, AZ 85251 Chairman Mr. Jeffrey T. Weikert Maricopa County Board of Supervisors Assistant General Counsel 301 W. Jefferson, 10th Floor El Paso Electric Company Phoenix, AZ 85003 Mail Location 167 123 W. Mills Mr. Aubrey V. Godwin, Director El Paso, TX 79901 Arizona Radiation Regulatory Agency 4814 S. 40th Street Mr. Eric Tharp Phoenix, AZ 85040 Los Angeles Department of Water & Power Southern California Public Power Authority Mr. Ron Barnes, Director P.O. Box 51111, Room 1255-C Regulatory Affairs Los Angeles, CA 90051-0100 Palo Verde Nuclear Generating Station Mail Station 7636 Mr. Brian Almon P.O. Box 52034 Public Utility Commission Phoenix, AZ 85072-2034 William B. Travis Building P.O. Box 13326 Mr. Dwight C. Mims, Vice President 1701 N. Congress Avenue Regulatory Affairs and Plant Improvement Austin, TX 78701-3326 Palo Verde Nuclear Generating Station Mail Station 7605 Mr. Randall K. Edington P.O. Box 52034 Executive Vice President Phoenix, AZ 85072-2034 Nuclear/CNO Arizona Public Service Company P.O. Box 52034, Mail Station 7602 Phoenix, AZ 85072-2034