ML25065A154
| ML25065A154 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 03/06/2025 |
| From: | John Lamb Plant Licensing Branch II |
| To: | Jeanne Johnston Southern Nuclear Operating Co |
| References | |
| L-2025-LLL-0002 | |
| Download: ML25065A154 (4) | |
Text
From:
John Lamb Sent:
Thursday, March 6, 2025 11:23 AM To:
Johnston, Jeanne D.
Cc:
Joyce, Ryan M.
Subject:
For Your Action - RAI - Vogtle 1 and 2 - License Renewal Commitment Item No. 20 (L-2025-LLL-0002)
- Jeanne, By \
letter dated January 16, 2025 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML25016A339), Southern Nuclear Operating Company (SNC, the licensee) submitted the license renewal commitment (LRC) Item No. 20, which requires a plant-specific analysis of certain reactor vessel internal components at the Vogtle Electric Generating Plant (Vogtle), Units 1 and 2, for the U.S. Nuclear Regulatory Commission (NRC) staff review and approval.
The NRC staff has determined that additional information is required for the staff to complete its review. The NRC staff sent the draft requestion for additional information (RAI) on March 5, 2025, to determine if SNC needed a clarifying call. On March 6, 2025, SNC said that a clarifying call was not needed, and SNC said it would respond to the below RAI within 30 days of the date of this email.
If you have any questions, please contact me.
John G. Lamb, Senior Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation REQUEST FOR ADDITIONAL INFORMATION By \
letter dated January 16, 2025 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML25016A339), Southern Nuclear Operating Company (SNC, the licensee) submitted the license renewal commitment (LRC) Item No. 20, which requires a plant-specific analysis of certain reactor vessel internal components at the Vogtle Electric Generating Plant (Vogtle), Units 1 and 2, for the U.S. Nuclear Regulatory Commission (NRC) staff review and approval.
The NRC staff has determined that additional information is required for the staff to complete its review.
Regulatory Basis The license renewal commitments that are part of the Updated Final Safety Analysis Report (UFSAR) are listed in Appendix A of NUREG-1920, Volume 2, Safety Evaluation Report Related to the License Renewal of Vogtle Electric Generating Plant, Units 1 and 2, dated April 2009 (ML091320236). LRC Item No. 20 requires the submission of an inspection plan for the reactor vessel internals at Vogtle, Units 1 and 2, to the NRC staff for review and approval at least 24 months prior to entering the periods of extended operation.
=
Background===
By \
letter dated January 16, 2025, SNC stated that the reactor vessel internals (RVI) inspections provided in MRP-227, Revision 1-A, Materials Reliability Program: Pressurized Water Reactor Internals Inspection and Evaluation Guidelines, (ML19339G350) have been incorporated into the Vogtle, Units 1 and 2, Reactor Internals Strategic Plan and that the reactor internals inspection plan for Vogtle, Units 1 and 2, is compliant with MRP-227 Revision 1-A. MRP-227, Rev 1-A has been previously reviewed and approved by the NRC staff.
Issues The NRC staff noted that SNCs inspection plan submitted in \
letter dated January 16, 2025, lacks information to determine whether Vogtle, Units 1 and 2, is bounded by MRP-227, Revision 1-A. Specifically, the NRC staff noted the following during its review of the licensees submittal:
- 1. Section 2.4, Guideline Applicability of MRP-227 Revision 1-A provides inspection and evaluation guidelines that are based on a broad set of assumptions about plant operation, which encompass the range of current plant conditions for the domestic fleet of pressurized-water reactors (PWRs). As such, Appendix B of MRP-227 Revision 1-A provides guidance on Plant-Specific Applicability Related to Fuel Design or Fuel Management and establishes limiting threshold values and ranges for several variables associated with neutron fluence and heat generation rates. Appendix B of MRP-227 Revision 1-A indicates that plants that exceed the thresholds defined above do not necessarily fall outside the MRP-227 recommendations; instead, they require additional evaluations to fully demonstrate plant-specific applicability. Thus, it is not clear to the NRC staff whether Vogtle, Units 1 and 2, was bounded by the thresholds established in Appendix B of MRP-227 Revision 1-A or whether additional evaluations were necessary to fully demonstrate plant-specific applicability.
- 2. Section 4, PWR Internals Management Requirements, of MRP-227 Revision 1-A provides guidelines for appropriate aging management to detect the expected effects of the degradation mechanisms for the RVIs. These inspection and evaluation guidelines are split into four categories (i.e., primary, expansion, existing programs, and no additional measures). SNC provided plant-specific details in its submittal regarding the primary inspection elements for its inspection plan; however, the primary category is not the only inspection category addressed by MRP-227, Revision 1-A. Thus, it is not clear to the NRC staff how the licensees inspection plan addresses the existing programs inspection category, especially for guidelines (e.g., components and supplemental guidance) beyond the inspections required by Section XI of the American Society of Mechanical Engineers (ASME) Code and Title 10 of the Code of Federal Regulations (10 CFR), Section 50.55a.
- 3. The NRC staffs safety evaluation for MRP-227, Rev 1, includes Applicant/Licensee Action Item #1, which is associated with the inspection and degradation of baffle-former-bolts. SNCs submittal does not provide any information regarding how Vogtle, Units 1 and 2, has addressed or will address Applicant/Licensee Action Item #1 of MRP-227, Revision 1-A.
Request for Additional Information (RAI)/Confirmation
- 1. Confirm that Vogtle, Units 1 and 2, is entirely bounded by the thresholds established in Appendix B of MRP-227 Revision 1-A. Otherwise, describe and justify any additional plant-specific evaluations that were necessary to fully demonstrate plant-specific applicability of MRP-227, Rev 1-A, to Vogtle, Units 1 and 2.
- 2. Confirm the following for the existing programs category of the Vogtle, Units 1 and 2, Reactor Vessel Internals inspection plan:
Consistent with MRP-227, Rev 1-A, the required ASME Section XI examinations are supplemented by Technical Bulletin (TB) 14-5, Reactor Internals Lower Radial Support Clevis Insert Cap Screw Degradation and TB 16-4, Fuel Alignment Pin Malcomized Surface Degradation.
Consistent with MRP-227, Rev 1-A, the flux thimble tubes (i.e., Item W13) continues to be managed by the program established in response to NRC Bulletin No. 88-09 (Microfiche 8807200246), Thimble Tube Thinning in Westinghouse Reactors.
Otherwise, describe and justify the methods that the RVIs inspection plan for Vogtle, Units 1 and 2, address the existing programs inspection category.
- 3. Describe and justify the actions that have been or will be taken to address Applicant/Licensee Action Item #1 of MRP-227, Revision 1-A.
Hearing Identifier:
NRR_DRMA Email Number:
2738 Mail Envelope Properties (MN2PR09MB508417C6DF7F1A72710E4CDFFACA2)
Subject:
For Your Action - RAI - Vogtle 1 and 2 - License Renewal Commitment Item No.
20 (L-2025-LLL-0002)
Sent Date:
3/6/2025 11:23:00 AM Received Date:
3/6/2025 11:22:00 AM From:
John Lamb Created By:
John.Lamb@nrc.gov Recipients:
"Joyce, Ryan M." <RMJOYCE@southernco.com>
Tracking Status: None "Johnston, Jeanne D." <JEAJOHNS@SOUTHERNCO.COM>
Tracking Status: None Post Office:
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