ML24257A101

Request for Additional Information License Renewal Commitment for AMP of Alloy 600 Components

ML24257A101
Person / Time
Site:	Palo Verde
Issue date:	09/11/2024
From:	William Orders Plant Licensing Branch IV
To:	Dilorenzo M Arizona Public Service Co
Orders, William
References
EPID L-2023-LRO-0092 Alloy 600
Download: ML24257A101 (1)

Text

From: William Orders To: Michael.Dilorenzo@aps.com

Subject:

REQUEST FOR ADDITIONAL INFORMATION Re: License Renewal Commitment for AMP of Alloy 600 Components (EPID L-2023-LRO -0092)

Date: September 11, 2024 M r. Dilorenzo, By letter dated February 22, 2024, Arizona Public Service Company (the licensee) submitted the Palo Verde Nuclear Generating Station (PVNGS) Units 1, 2 and 3, Alloy 600 Management Program Plan to the U.S. Nuclear Regulatory Commission (NRC) for review in c ompliance with license renewal Commitment 23 of Table 19.5-1 of the PVNGS Updated Final Safety Analysis Report (UFSAR).

In order for NRC staff to complete the review of the submittal, the NRC staff requests confirmation of the items listed in the attached Request for Additional Information to ensure the items are incorporated into the Alloy 600 Management Program Plan for PVNGS Units 1, 2 & 3.

Please advise me if you request a confirmation call to address these items or provide a response to these questions within 30 days of this e-mail communication.

A publicly available version of this communication will be placed in ADAMS, the NRCs official document repository system. Please contact me if you have any questions concerning this request.

William T. Orders Senior Project Manager Plant Licensing Branch 4 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Phone: (301) 415-3329 Willam.Orders@nrc.gov

1 REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION PALO VERDE UNITS 1 2 3 - LICENSE RENEWAL COMMITMENT 23A, "ALLOY 600 MANAGEMENT PROGRAM PLAN" ARIZONA PUBLIC SERVICE COMPANY PALO VERDE, UNITS 1, 2, 3 DOCKET NO. 05000528, 05000529, 05000530 ISSUE DATE: 09/12/2024

=

Background===

By letter dated February 22, 2024 (ADAMS Accession No. ML24053A397), Arizona Public Service Company (APS or the licensee) submitted the Palo Verde Nuclear Generating Station (PVNGS) Units 1, 2 and 3, Alloy 600 Management Program Plan to the U.S. Nuclear Regulatory Commission (NRC) for review in compliance with license renewal Commitment 23 of Table 19.5-1 of the PVNGS Updated Final Safety Analysis Report (UFSAR). In Section 6.4, RCS [reactor coolant system] Dissimilar Metal Butt-Welds, Table 3 of the submi ttal provides the current inspection requirements for dissimilar metal welds.

Regulatory Basis

In order for NRC staff to complete the review of this section, the NRC staff request confirmation on the following items to ensure they are incorporated into the Alloy 600 Management Program Plan for PVNGS Units 1, 2 & 3.

Question 1

The licensee identified several of the PVNGS Units 1, 2 & 3, ASME Code Class 1 dissimilar metal (DM) butt welds were mitigated by the full structural weld overlay (FSWOL). These FSWOL welds are required to be inspected in accordance with ASME Code N-770 -5, Alternative Examination Requirements and Acceptance Standards for Class 1 PWR Piping and Vessel Nozzle Butt Welds Fabricated With UNS N06082 or UNS W86182 Weld Filler Material With or Without Application of Listed Mitigation Activities,Section XI, as m andated by 10 CFR 50.55a(g)(6)(ii)(F), Augmented ISI requirements:

Examination requirements for Class 1 piping and nozzle dissimilar metal butt welds.

Note 10 of ASME Code N-770-5 states, in part, Those welds not included in the 25 percent sample shall be examined prior to the end of the mitigation evaluation period if the plant is to be operated beyond that time.

Confirm that the licensee has reviewed the design basis for each of these FSWOL welds for the period of extended operation to verify the reinspection frequency in accordance

2 with Note 10 of ASME Code Case N-770-5 are incorporated into the Alloy 600 Management Program Plan.

Question 2

Due to industry operating experience (OE), Electric Power Research Institute (EPRI)

Technical Report 3002012244, Revision 3, Nondestructive Evaluation: Guideline for Conducting Ultrasonic Examinations of Dissimilar Metal Welds, dated February 2018, provides enhanced guidance and Nuclear Energy Institute (NEI) 03-08, Guideline for the Management of Materials Issues requirements and recommendations for the examinations of DM welds.

Confirm that the licensee has reviewed EPRI Technical Report 3002012244, Revision 3, and incorporated the enhanced guidance requirements and recommendations in accordance with NEI 03-08 in the Alloy 600 Management Program Plan for DM weld examinations.

3