NL-23-0080, Response to Request for Additional Information (RAI) Related to Proposed Inservice Inspection Alternative FNP-ISI-ALT-05-05, Version 1.0
| ML23033A603 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 02/02/2023 |
| From: | Gayheart C Southern Nuclear Operating Co |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| NL-23-0080 | |
| Download: ML23033A603 (1) | |
Text
Regulatory Affairs 3535 Colonnade Parkway Birmingham AL 35243 205 992 5000 February 2, 2023 Docket Nos.: 50-348 NL-23-0080 50-364 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Joseph M. Farley Nuclear Plant - Units 1 and 2 Response to Request for Additional Information (RAI) Related to Proposed Inservice Inspection Alternative FNP-ISI-ALT-05-05, Version 1.0 Ladies and Gentlemen:
By letter dated September 30, 2022 (agencywide Documents Access and Management System (ADAMS) Accession No. ML22273A159), in accordance with 10 CFR 50.55a(z)(1),
Southern Nuclear Operating Company (SNC) requested Nuclear Regulatory Commission (NRC) approval of proposed inservice inspection (ISI) alternative FNP-ISI-ALT-05-05, Version 1.0 for Joseph M. Farley Nuclear Plant (FNP) Units 1 and 2. This proposed alternative requested to increase the inspection interval for ASME Section XI, Table IWC-2500-1, exam Category C-B, item number C2.21 and C2.22, exams from 10 years to 20 years through the remainder of the 5th interval as well as the duration of the 6th ISI Interval.
By email dated January 3, 2023 (ML23003A809), the U.S. Nuclear Regulatory Commission (NRC) notified SNC that additional information is needed for the staff to perform their review.
The enclosure to this letter provides the SNC response to the NRC Request for Additional Information (RAI).
This letter contains no regulatory commitments. If you have any questions, please contact Amy Chamberlain at 205.992.6361.
Respectfully submitted, Cheryl A. Gayheart Regulatory Affairs Director CAG/was/cbg
Enclosure:
SNC Response to NRC Request for Additional Information
U. S. Nuclear Regulatory Commission NL-23-0080 Page 2 cc: Regional Administrator, Region ll NRR Project Manager - Farley Nuclear Plant Senior Resident Inspector - Farley Nuclear Plant RTYPE: CFA04.054
Joseph M. Farley Nuclear Plant Unit 1 and 2 Response to Request for Additional Information (RAI) Related to Proposed Inservice Inspection Alternative FNP-ISI-ALT-05-05, Version 1.0 Enclosure SNC Response to NRC Request for Additional Information
Enclosure to NL-23-0080 SNC Response to NRC Request for Additional Information E-1 REQUEST FOR ADDITIONAL INFORMATION (RAI)
By letter dated September 30, 2022, Southern Nuclear Operating Company (SNC, the licensee) [submitted] an inservice inspection (ISI) alternative request for Joseph M.
Farley Nuclear Plant (Farley), Units 1 and 2. SNC is requesting an ISI alternative to the examination requirements of American Society of Mechanical Engineers (ASME)Section XI, Table IWC-2500-1, Examination Category C-B, Item Nos. C2.21 and C2.22. The proposed alternative by SNC is to increase the inspection interval for these Item Nos. for the replacement steam generators (SGs) to 20 years (from the current ASME Code,Section XI 10-year requirement).
Specifically, pursuant to Title 10 of the Code of Federal Regulations, Part 50, Section 55a, Paragraph (z)(1) (10 CFR 50.55a(z)(1)), the licensee is proposing to increase the ISI interval for the subject SG welds of FNP Unit 1 and 2 from the current ASME Code,Section XI 10-year requirement to 20 years for the remainder of the fifth 10-year ISI interval and through the sixth 10-year ISI interval, which is currently scheduled to end on November 30, 2037. The licensee referred to the results of the probabilistic fracture mechanics (PFM) analyses in non-proprietary Electric Power Research Institute (EPRI)
Technical Report 3002014590, Technical Bases for Inspection Requirements for PWR Steam Generator Class 1 Feedwater and Main Steam Nozzle-to-Shell Welds and Nozzle Inside Radius Sections, 2019 (ADAMS Accession No. ML19347B107) as the primary basis for the deferral of the ISI examinations.
The U.S. Nuclear Regulatory Commission (NRC) staff reviewed the ISI alternative request and determined that more information is needed to complete its review.
Regulatory Analysis Basis The NRC has established requirements in 10 CFR Part 50 to protect the structural integrity of structures and components in nuclear power plants. Among these requirements are the ISI requirements of Section XI of the ASME Code incorporated by reference in 10 CFR 50.55a to ensure that adequate structural integrity of SG vessels (including their welds) is maintained through the service life of the vessels. Therefore, the regulatory basis for the following request for additional information (RAI) has to do with demonstrating that the proposed alternative ISI requirements would ensure adequate structural integrity of the SG welds of Farley, Units 1 and 2, and thereby would provide an acceptable level of quality and safety per 10 CFR 50.55a(z)(1) for the welds.
RAI No. 1 Issue In Section 5.0 of the enclosure to the submittal, the licensee is proposing to increase the ISI interval for the subject SG welds of Farley, Units 1 and 2, from the current ASME Code,Section XI 10-year requirement to 20 years for the remainder of the fifth 10-year ISI interval and through the sixth 10-year ISI interval, which is currently scheduled to end on November 30, 2037. The licensee stated that all exams will be scheduled to occur in the same period as the last examination, but with a two interval inspection periodicity.
The licensee provided the inspection history of the affected components in Appendix B of the enclosure to the submittal. The NRC staff reads the stated two interval inspection
Enclosure to NL-23-0080 SNC Response to NRC Request for Additional Information E-2 periodicity as being a 20-year period, but for clarity would like the estimated dates for the next examinations of the affected components.
Request Given the licensees proposed alternative in Section 5.0 of the enclosure to the submittal, the inspection history of the affected components in Appendix B of the enclosure to the submittal, and the NRC staffs understanding of two interval inspection periodicity as being a 20-year period, provide estimated dates (expected to be before the end of the sixth 10-year ISI interval on November 30, 2037) for the next examinations of the affected components listed in Section 1.0 of the enclosure to the submittal.
SNC Response:
Table 1, shown on the next page, provides inspection scheduling details for components affected by this request for alternative. Note that the first 4 columns of Table 1 below are contained in Appendix B of the original submittal, SNC letter NL-22-0756 (ML22273A159). As stated in that letter, The proposed alternative is to increase the inspection interval for these Item Nos. for the Unit 1 [and 2] replacement SGs to 20 years (from the current ASME Code,Section XI 10-year requirement) for the remainder of the fifth 10-year inspection interval and through the sixth 10-year inspection interval, which is currently scheduled to end on 11/30/2037. All exams will be scheduled to occur in the same period as the last examination, but with a two interval inspection periodicity. As shown in Table 1, inspections that would otherwise be required to be performed in the remainder of the fifth 10-year inspection interval and through the sixth 10-year inspection interval are proposed to be extended to a 20 year interval from the last performance.
Enclosure to NL-23-0080 SNC Response to NRC Request for Additional Information E-3 Table 1 Note 1:
The proposed alternative would allow the examination for APR2-3100-8R, currently scheduled for the 6th interval, not to be performed during the 6th interval. The exam for this component was completed during the 5th interval.
Therefore, this alternative would allow the future examination for APR2-3100-Date Interval
/ Period Components ID Next Examination Interval /
Period Next Examination Window Item No.
C2.21 1R20 Spring 2006 3rd/3rd ALA2-3300-8R 1R27 Fall 2016 4th/3rd ALA2-3300-8R ALA2-3300-8R 6th/3rd 12/1/2034 - 11/30/2037 2R20 Spring 2010 4th/1st APR2-3100-8R 2R27 Fall 2020 5th/1st APR2-3100-8R APR2-3100-8R 7th/1st (Note 1) 12/1/2037 - 11/30/2040 Item C2.22 1R20 Spring 2006 3rd/3rd ALA2-3300-IR8R 1R25 Fall 2013 4th/ 2nd ALA2-3300-IR8R ALA2-3300-IR8R 6th/2nd 12/1/2030 - 11/30/2034 2R20 Spring 2010 4th/1st APR2-3100-IR8R (Note 2) 2R25 Fall 2017 4th/3rd APR2-3200-IR8R (Note 2)
APR2-3100-IR8R 6th/3rd 12/1/2034 - 11/30/2037
Enclosure to NL-23-0080 SNC Response to NRC Request for Additional Information E-4 8R to be delayed until the 7th interval, during the same period as previously performed in the 5th interval.
Note 2:
An additional examination of the ASME Section XI item C2.22 weld was performed in the 4th Interval due to the understanding at the time of the percentage requirements. SNC proposes to use the exam set date for component APR2-3200-IR8R since this exam was the most recent Unit 2 ASME Section XI item C2.22 examination performed, but the scheduled examination will be the original component selected for examination, APR2-3100-IR8R.