ML23334A161

NRR E-mail Capture - Palo Verde 1, 2, and 3 - RAIs Associated with License Renewal Commitment for Pressurizer Surge Line Welds Inspection Program to Manage Environmentally Assisted Fatigue

ML23334A161
Person / Time
Site:	Palo Verde
Issue date:	11/30/2023
From:	Siva Lingam NRC/NRR/DORL/LPL4
To:	Cox M Arizona Public Service Co
References
L-2023-LRM-0052
Download: ML23334A161 (5)

Text

From: Siva Lingam Sent: Thursday, November 30, 2023 2:06 PM To: Matthew.Cox@aps.com Cc: Jennifer Dixon-Herrity; Jennie Rankin; Stewart Bailey; Matthew Mitchell; Kaihwa Hsu; Seung Min

Subject:

Palo Verde 1, 2, and 3 - RAIs Associated with License Renewal Commitment for Pressurizer Surge Line Welds Inspection Program to Manage Environmentally Assisted Fatigue (EPID L-2023-LRM-0052)

Please note the following official requests for additional information (RAIs) for the subject submittal. We transmitted the draft RAIs to you on November 6, 2023, and held a clarification call on November 30, 2023, at your request. Please provide your responses within 45 days from the date of this email.

By letter dated July 26, 2023 (Agencywide Documents Access and Management System Accession No. ML23207A248), Arizona Public Service Company (the licensee) proposed method to manage environmentally assisted fatigue (EAF) for the pressurizer surge line during the period of extended operation, as committed during license renewal, for U.S Nuclear Regulatory Commission (NRC) approval for Palo Verde Nuclear Generating Station, Units 1, 2, and 3 (Palo Verde).

Regulatory Requirements The licensee manages the aging effects of EAF on the pressurizer surge line using periodic inspections performed at a frequency determined by a flaw tolerance evaluation in accordance with American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME BPV Code)Section XI, Non-mandatory Appendix L, Operating Plant Fatigue Assessment.

Pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 54.21, Contents of application - technical information, each application for license renewal must contain an integrated plant assessment (IPA) and an evaluation of time limited aging analyses. The plant-specific IPA shall identify and list those structures and components subject to an aging management review and demonstrate that the effects of aging will be adequately managed so that their intended functions will be maintained consistent with the current licensing basis for the period of extended operation as required by 10 CFR 54.21(a)(3).

Specifically, the regulations in 10 CFR 54.21(c)(1)(iii) states, The effects of aging on the intended function(s) will be adequately managed for the period of extended operation.

Requests for Additional Information EMIB-RAI-1 Paris' Law is a fatigue crack growth equation that gives the rate of growth of a fatigue crack.

da/dN is the fatigue crack growth for a load cycle. However, the licensees calculation (See Table 2 of Document ID: N001-0607-00483) used fraction cycle to evaluate the crack growth (e.g., transient 1 with 1.398 cycles/year, transient 2 with 1.39 cycles/year, transient 3 with 0.531 cycle/year, transient 4 with 3.06 cycles/year, transients 6 and 7 with 2.695 cycles/year, transients 9 and 10 with 0.042 cycle/year). The NRC staff notes that the fractional cycle does not represent whole cycles or relevant crack growth. In addition, transients 9 and 10 with 10

years inspection period have 0.42 cycle/10years. The NRC staff is requesting the licensee to clarify the method with fractional (non-integer) cycles in the crack growth evaluation.

EMIB-RAI-2 The licensee states that the temperature for crack growth is taken as the average temperature of each transient in the page 13 of the licensees Document (N001-0607-00485): Fatigue Crack Growth Calculation for the Palo Verde Surge Line Appendix L Evaluation. The NRC staff is requesting the licensee to provide the technical basis for using average temperature for crack growth.

EMIB-RAI-3 The licensee used the following table to determine the maximum and minimum Stress Intensity Factors (Kmax and Kmin):

The NRC staff notes that the Kmax (or Kmin) for the thermal transient pressure and temperature may not occur at the same time, e.g., during cooldown the inside surface stress increases and pressure stress decreases. Therefore, the licensees combination of all the Kmax (or Kmin) values for different cases may not be adequate. Please clarify.

NPHP-RAI-1 Section 3.0 of the licensees submittal addresses the operating experience program element of the Pressurizer Surge Line Inspection Program. In comparison, NUREG-1800, Revision 2, Standard Review Plan for Review of License Renewal Applications for Nuclear Power Plants, dated December 2010, Appendix A, Branch Technical Positions, section A.1.2.3.10, Operating Experience indicates that future industry operating experience should be reviewed to confirm the effectiveness of its aging management programs.

Clarify whether the licensee will continue to review industry operating experience related to EAF in pressurizer surge lines to confirm the effectiveness of the licensees program during the period of extended operation. If not, provide justification for why such review of relevant industry operation experience is not necessary.

Siva P. Lingam U.S. Nuclear Regulatory Commission Project Manager Palo Verde Nuclear Generating Station, Units 1, 2, and 3 Grand Gulf Nuclear Station Entergy Fleet

Location: O-9E22; Mail Stop: O-9E03 Telephone: 301-415-1564 E-mail address: Siva.Lingam@nrc.gov

Hearing Identifier: NRR_DRMA Email Number: 2322 Mail Envelope Properties (SJ0PR09MB61095E900884452617C2FBCDF682A)

Subject:

Palo Verde 1, 2, and 3 - RAIs Associated with License Renewal Commitment for Pressurizer Surge Line Welds Inspection Program to Manage Environmentally Assisted Fatigue (EPID L-2023-LRM-0052)

Sent Date: 11/30/2023 2:06:05 PM Received Date: 11/30/2023 2:06:00 PM From: Siva Lingam Created By: Siva.Lingam@nrc.gov Recipients:

"Jennifer Dixon-Herrity" <Jennifer.Dixon-Herrity@nrc.gov>

Tracking Status: None "Jennie Rankin" <Jennivine.Rankin@nrc.gov>

Tracking Status: None "Stewart Bailey" <Stewart.Bailey@nrc.gov>

Tracking Status: None "Matthew Mitchell" <Matthew.Mitchell@nrc.gov>

Tracking Status: None "Kaihwa Hsu" <Kaihwa.Hsu@nrc.gov>

Tracking Status: None "Seung Min" <Seung.Min@nrc.gov>

Tracking Status: None "Matthew.Cox@aps.com" <Matthew.Cox@aps.com>

Tracking Status: None Post Office: SJ0PR09MB6109.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 4919 11/30/2023 2:06:00 PM image001.png 63265 Options Priority: Normal Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date: