ML24113A250
| ML24113A250 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 04/22/2024 |
| From: | Richard Guzman NRC/NRR/DORL/LPL1 |
| To: | Sinha S NRC/NRR/DORL/LPL1 |
| References | |
| EPID L-2023-LRO-0092 | |
| Download: ML24113A250 (1) | |
Text
From:
Richard Guzman To:
Shayan Sinha
Subject:
Millstone Power Station, Unit No. 3 - REQUEST FOR ADDITIONAL INFORMATION Re: License Renewal Commitment for AMP of Alloy 600 Components (EPID L-2023-LRO-0092)
Date:
Monday, April 22, 2024 2:48:38 PM
- Shayan,
On April 5, 2024, the U.S. Nuclear Regulatory Commission (NRC) staff sent Dominion Energy Nuclear Connecticut, Inc. (DENC, the licensee) the subject Request for Additional Information (RAI) as a draft e-mail. This RAI supports the staffs review of the licensees November 20, 2023, letter (ML23324A430), describing its revised aging management program for the management of nickel-based allow (also referred to as Allow 600) in accordance with Commitment Item No. 15 of NUREG-1838, the safety evaluation report for the renewed operating license for Millstone Power Station, Unit No. 3 (MPS3).
The NRC staff and DENC held a conference call on April 22, 2024, to discuss clarifications on the draft RAI.Updated below is the official (final) RAI.As discussed on the call, please provide a response to these questions within 30 days of this e-mail communication or no later than May 22, 2024. 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.
Richard V. Guzman Senior Project Manager Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Office: O-9C7 l Phone: (301) 415-1030 Richard.Guzman@nrc.gov
FINAL-------------------------------------------------
REQUEST FOR ADDITIONAL INFORMATION ALLOY 600 AGING MANAGEMENT PROGRAM SUBMITTAL RELATED TO LICENSE RENEWAL COMMITMENT NO. 15 DOMINION ENERGY NUCLEAR CONNECTICUT, INC MILLSTONE POWER STATION, UNIT 3 DOCKET NO. 50-423 L-2023-LRO-0092
By letter dated November 20, 2023 (ADAMS Accession No. ML23324A430), Dominion
Energy Nuclear Connecticut, Inc. (the licensee) submitted a description of its revised aging management program (AMP) for management of nickel-based allow (also referred to as Allow 600) in accordance with Commitment Item No. 15 of NUREG-1838, the safety evaluation report for the renewed operating license for Millstone Power Station, Unit No. 3 (MPS3). To complete its review of the submittal, the U.S. Nuclear Regulatory Commission (NRC) staff requests the following additional information:
On page 2 of 10 of the Attachment to the November 20, 2023, letter, the licensee noted that the MPS3 Alloy 600 Inspection program had evolved to implement the requirements of applicable NRC publications and industry guidance, including References 6.14, 6.15 and 6.16. Further, the licensee noted that the Dominion Nuclear Fleet Alloy 600 Management Plan is described in Program Description ER-AA-MAT-11 and is applicable to all Alloy 600/82/182 components in primary systems at Dominion nuclear plants. As part of these activities, the NRC staff requests that the licensee confirm that the following actions have been addressed within these aging management programs for MPS3 for the period of license renewal.
- 1. The licensee identified several of the MPS3 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 mandated 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 that the reinspection frequency in accordance with Note 10 of ASME Code Case N-770-5 are incorporated into the aging management program.
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, (ML19079A256) 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 aging management program.
- 3. NRC Regulator Issuance Summary (RIS) 2015-10, Applicability of ASME Code Case N770-1 as Conditioned in 10 CFR 50.55a, Codes and Standards, to Branch Connection Butt Welds, (ML15068A131) issued on July 16, 2015, informs nuclear utilities about reactor coolant system (RCS) Alloy 82/182 branch connection DM nozzle welds that may be of a butt weld configuration, and therefore require inspection under 10 CFR 50.55a(g)(6)(ii)(F), Augmented ISI requirements:
Examination requirements for Class 1 piping and nozzle dissimilar-metal butt welds.
Confirm that the licensee has reviewed RIS 2015-10 for applicability to MPS3 and taken any corrective actions necessary to ensure compliance with 10 CFR 50.55a(g)
(6)(ii)(F).
- 4. Due to lessons learned and industry OE, EPRI Report 3002017288, Materials Reliability Program: Guideline for Nondestructive Examination of Reactor Vessel Upper Head Penetrations, Revision 1 (MRP-384), dated 2019, as required under NEI 03-08 implementation criteria, provides guidance for planning and executing reactor vessel upper head penetration examinations.
Confirm that the licensee has reviewed MRP-384 and incorporated the enhanced guidance requirements and recommendations in accordance with NEI 03-08 in the AMP.
- 5. NRC RIS 2018-06, Clarification of the Requirements for Reactor Pressure Vessel Upper Head Bare Metal Visual Examinations, issued on December 10, 2018 (ML18178A137), informs nuclear utilities about acceptable methodologies to evaluate relevant conditions that require further evaluation when performing bare metal visual examinations of the RPV upper head.
Confirm that the licensee has reviewed RIS 2018-06 for applicability to inspection programs and procedures at MPS3 and has taken any corrective actions necessary to ensure compliance with 10 CFR 50.55a(g)(6)(ii)(D).
FINAL-----------------------------------------------
From: Richard Guzman Sent: Friday, April 5, 2024 3:48 PM To: Shayan Sinha <Shayan.Sinha@dominionenergy.com>
Subject:
Millstone Power Station, Unit No. 3 - DRAFT Request for Additional Information Re: License Renewal Commitment for AMP of Alloy 600 Components (EPID L-2023-LRO-0092)
- Shayan,
By letter dated November 20, 2023 (ADAMS Accession No. ML23324A430), Dominion Energy Nuclear Connecticut, Inc., submitted a description of its revised aging management program (AMP) for management of nickel-based allow (also referred to as Allow 600) in accordance with Commitment Item No. 15 of NUREG-1838, the safety evaluation report for the renewed operating license for Millstone Power Station, Unit No. 3. The NRC staff is reviewing the submittal and has determined that additional information is needed to complete its review, as described in the request for additional information (RAI) shown below. This RAI is identified as DRAFT at this time to confirm your understanding of the information needed by the NRC staff to complete its evaluation. Please let me know your availability for a clarification call, and I will coordinate availabilities w/the NRC technical staff. I would like to hold the call by April 19th, as I plan to issue the questions as an official RAI no later than April 24th.
- Thanks,
Rich Guzman Sr. PM, Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Office: O-9C7 l Phone: (301) 415-1030 Richard.Guzman@nrc.gov