ML24079A006
| ML24079A006 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 04/10/2024 |
| From: | Markley M Plant Licensing Branch II |
| To: | Coleman J Southern Nuclear Operating Co |
| References | |
| EPID L 2023 LLR 0023 | |
| Download: ML24079A006 (1) | |
Text
April 10, 2024 Ms. Jamie M. Coleman Regulatory Affairs Director Southern Nuclear Operating Co., Inc.
3535 Colonnade Parkway Birmingham, AL 35243
SUBJECT:
VOGTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2 - PROPOSED ALTERNATIVE TO THE REQUIREMENTS OF AMERICAN SOCIETY OF MECHANICAL ENGINEERS CODE FOR OPERATION AND MAINTENANCE OF NUCLEAR POWER PLANTS FOR PRESSURE ISOLATION VALVE TESTING FREQUENCY (EPID L-2023-LLR-0023)
Dear Jamie Coleman:
By letter dated May 1, 2023 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23121A267)), as supplemented by letters dated November 17, 2023 (ML23321A242) and February 8, 2024 (ML24039A175), Southern Nuclear Operating Company (SNC, the licensee) submitted Alternative Request ALT-VR-02 to the U.S. Nuclear Regulatory Commission (NRC) proposing the use of an alternative to specific requirements in the 2004 Edition through the 2006 Addenda of the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code) at Vogtle Electric Generating Plant (Vogtle), Units 1 and 2, associated with the fourth 10-year inservice testing (IST) program interval.
Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(z)(1), the licensee requested to use the proposed alternative on the basis that the alternative provides an acceptable level of quality and safety.
The NRC staff has reviewed the subject request and concludes, as set forth in the enclosed safety evaluation, that SNC has addressed adequately all the regulatory requirements set forth in 10 CFR 50.55a(z)(1). Therefore, the NRC staff authorizes the use of Alternative Request ALT-VR-02 at Vogtle, Units 1 and 2, for the remainder of the fourth 10-year inservice testing program interval, which is scheduled to end on May 31, 2027.
J. Coleman All other ASME OM Code requirements for which relief was not requested specifically and approved remain applicable.
If you have questions, you can contact me at 301-415-2258 or Zachary.Turner@nrc.gov.
Sincerely, Michael Markley, Chief Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-424 and 50-425
Enclosure:
Safety Evaluation for Vogtle cc: Listserv MICHAEL MARKLEY Digitally signed by MICHAEL MARKLEY Date: 2024.04.10 09:30:29 -04'00'
Enclosure SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION ALTERNATIVE REQUEST ALT-VR-02 TITLE 10 OF THE CODE OF FEDERAL REGULATIONS PART 50, APPENDIX J, FOR PRESSURE ISOLATION VALVE TEST FREQUENCIES FOURTH 10-YEAR INTERVAL INSERVICE TESTING PROGRAM SOUTHERN NUCLEAR OPERATING COMPANY VOGTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2 DOCKET NOS. 50-424 AND 50-425 EPID: L-2023-LLR-0023
1.0 INTRODUCTION
By letter dated May 1, 2023 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23121A267), as supplemented by letters dated November 17, 2023 (ML23321A242) and February 8, 2024 (ML24039A175), Southern Nuclear Operating Company (SNC, the licensee) submitted Alternative Request ALT-VR-02 to the U.S. Nuclear Regulatory Commission (NRC) proposing the use of an alternative to specific requirements in the 2004 Edition through the 2006 Addenda of the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code) at Vogtle Electric Generating Plant (Vogtle), Units 1 and 2, associated with the fourth 10-year inservice testing (IST) program interval.
Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR)
Section 50.55a(z)(1), Acceptable level of quality and safety, the licensee requested to implement Alternative Request ALT-VR-02 on the basis that the proposed alternative would provide an acceptable level of quality and safety.
The fourth 10-year IST program interval for Vogtle, Units 1 and 2, began on June 1, 2017, and is scheduled to end on May 31, 2027. The licensee proposed that Alternative Request ALT-VR-02 be authorized for the remainder of the fourth 10-year IST program interval.
J. Coleman
2.0 REGULATORY EVALUATION
The NRC regulations in 10 CFR 50.55a(f)(4), Inservice testing standards requirement for operating plants, state that throughout the service life of a boiling or pressurized water-cooled nuclear power facility, pumps and valves that are within the scope of the ASME OM Code must meet the IST requirements (except design and access provisions) set forth in the ASME OM Code and addenda that become effective subsequent to editions and addenda specified in 10 CFR 50.55a(f)(2) and (3) and that are incorporated by reference in 10 CFR 50.55a(a)(1)(iv),
to the extent practical within the limitations of design, geometry, and materials of construction of the components. The IST requirements for pumps and valves that are within the scope of the ASME OM Code but are not classified as ASME Boiler and Pressure Vessel Code Class 1, Class 2, or Class 3 may be satisfied as an augmented IST program in accordance with 10 CFR 50.55a(f)(6)(ii) without requesting relief under 10 CFR 50.55a(f)(5) or alternatives under 10 CFR 50.55a(z). This use of an augmented IST program is acceptable without prior NRC approval provided the basis for deviations from the ASME OM Code, as incorporated by reference in this section, demonstrates an acceptable level of quality and safety, or that implementing the Code provisions would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety, where documented and available for NRC review.
The NRC regulations in 10 CFR 50.55a(z), Alternatives to codes and standards requirements, state:
Alternatives to the requirements of paragraphs (b) through (h) of this section or portions thereof may be used when authorized by the Director, Office of Nuclear Reactor Regulation. A proposed alternative must be submitted and authorized prior to implementation. The applicant or licensee must demonstrate that:
(1) Acceptable level of quality and safety. The proposed alternative would provide an acceptable level of quality and safety; or (2) Hardship without a compensating increase in quality and safety. Compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
3.0 TECHNICAL EVALUATION
The information provided by the licensee in support of the request for an alternative to ASME OM Code was evaluated by, the NRC, and the results of its evaluation are documented below.
3.1 Licensees Proposed Alternative ALT-VR-02 Applicable Code Edition The applicable Code of record for the fourth 10-year IST program interval at Vogtle, Units 1 and 2, is the ASME OM Code, 2004 Edition through the 2006 Addenda.
J. Coleman ASME Code Components Affected In its submittal, the licensee proposed alternative testing for the following 60 pressure isolation valves (PIVs):
Table 1 Valve Number Units 1 and 2 Description System1 ASME Code Class OM Code Category2 1/2-HV-8701A/B RHR Pump Supply Isolation From RCS Loops RCS 1
A 1/2-HV-8702A/B RHR Pump Supply Isolation From RCS Loops RCS 1
A 1/2-1204-U4-143 1/2-1204-U4-144 1/2-1204-U4-145 1/2-1204-U4-146 SI To RCS Cold Leg Isolation Check Valve SI 1
A/C 1/2-1204-U4-120 1/2-1204-U4-121 1/2-1204-U4-123 1/2-1204-U4-122 SI to RCS Hot Leg Isolation Check Valve SI 1
A/C 1/2-1204-U6-079 1/2-1204-U6-080 1/2-1204-U6-081 1/2-1204-U6-082 SI Accumulator Discharge Check Valve SI 1
A/C 1/2-1204-U6-083 1/2-1204-U6-084 1/2-1204-U6-085 1/2-1204-U6-086 SI/RHR Cold Leg Admission Check Valve SI 1
A/C 1/2-1204-U6-147 1/2-1204-U6-148 1/2-1204-U6-149 1/2-1204-U6-150 RHR To RCS Cold Leg Isolation Check Valve SI 1
A/C 1/2-1204-U6-128 1/2-1204-U6-129 RHR To RCS Hot Leg Isolation Check Valve SI 1
A/C 1/2-1204-U6-126 1/2-1204-U6-124 1/2-1204-U6-127 1/2-1204-U6-125 RCS Hot Leg SI Admission Check Valve SI 1
A/C Note: All valves in Table 1 are included in the scope of the Vogtle, Units 1 and 2, fourth 10-year interval IST Plan.
Note 1: SI - Safety Injection RCS - Reactor Coolant System RHR - Residual Heat Removal Note 2:
Category A - Valves for which seat leakage is limited to a specific maximum amount in the closed position.
J. Coleman Category A/C - Check valves for which seat leakage is limited to a specific maximum amount in the closed position.
Applicable Code Requirement
The IST requirements in the ASME OM Code, 2004 Edition through 2006 Addenda, as incorporated by reference in 10 CFR 50.55a, related to this alternative request are as follows:
ASME OM Code, Subsection ISTC, Inservice Testing of Valves in Light-Water Reactor Nuclear Power Plants, paragraph ISTC-3522, Category C Check Valves, subparagraph (a), states in part:
During operation at power, each check valve shall be exercised or examined in a manner that verifies obturator travel by using the methods in ISTC-5221.
Each check valve exercise test shall include open and close tests.
ASME OM Code, Subsection ISTC, paragraph ISTC-3522, subparagraph (c), states:
If exercising is not practicable during operation at power and cold shutdowns, it shall be performed during refueling outages.
ASME OM Code, Subsection ISTC, paragraph ISTC-3630, Leakage Rate for Other Than Containment Isolation Valves, states:
Category A valves with a leakage requirement not based on an Owners 10 CFR 50, Appendix J, program, shall be tested to verify their seat leakages
[are] within acceptable limits. Valve closure before seat leakage testing shall be by using the valve operator with no additional closing force applied.
ASME OM Code, Subsection ISTC, paragraph ISTC-3630, subparagraph (a), Frequency, states:
Tests shall be conducted at least once every 2 yr [years].
Licensees Proposed Alternative and Basis for Use In its letter dated May 1, 2023, the licensee stated:
In accordance with 10 CFR 50.55a, "Codes and standards," paragraph (z)(1),
"Alternatives to codes and standards requirements," SNC proposes the following alternative to the ASME OM Code requirements. The specific test interval for each PIV would be a function of its historical performance and would be established in a manner consistent with the containment isolation valve testing process under 10 CFR 50, Appendix J, Option B. Performance-based scheduling of PIV testing will be controlled in a manner consistent with the prescribed frequency described in NEI 94-01, Revision 3-A. PIV test performances would occur at a nominal frequency ranging from every refueling outage to every fourth refueling outage, subject to acceptable valve performance. Valves that have demonstrated good performance for two consecutive cycles may have their test
interval extended up to 75-months, with a permissible extension (for non-routine emergent conditions) of nine months (84 months total).
Conservative controls will be established such that if any valve fails the PIV test, the test interval will be reduced consistent with Appendix J, Option B, requirements. PIV test failure is defined as the low-pressure and high-pressure tests exceeding the Maximum Allowable Leak Rate. Any PIV leakage test failure would require the component be returned to the initial ASME OM Code interval until good performance can again be established.
The primary basis for this proposed alternative is the excellent performance history of the VEGP PIVs. Table 2, "PIV Leakage Test History for VEGP Units 1 and 2" provides the leakage history for the 30 subject PIVs for each unit for eight consecutive refueling outage test performances.
The functional capability of the check valves is demonstrated by exercise testing which consist of open and close tests. The open testing is separate and distinct from the PIV testing and is currently performed in accordance with the Condition Monitoring Program, currently every 54 months. The close testing will take credit for the PIV leak rate testing and will be on the same frequency as the PIV leak rate testing. The fact that the PIVs exhibit excellent historical performance (i.e., none of the check valve test results have exceeded the Required Action Limit) shows that the Category A/C check valves are exhibiting the required obturator movement to close and remain closed.
Note that NEI 94-01, Revision 3-A, is not the sole basis for this alternative since NEI 94-01, Revision 3-A does not address seat leakage testing with water. This NEI document is being cited as an approach similar to the requested alternative method for determining test frequency. If the proposed alternative is authorized and the valves exhibit good performance, the PIV test frequency will be controlled consistent with the prescribed frequency described in NEI 94-01, Revision 3-A, so that testing of these PIVs would not be required each refueling outage.
The proposed extension of test frequencies is consistent with the guidance provided in 10 CFR 50, Appendix J, Type C leak rate tests as detailed in NEI 94-01, Revision 3-A, Paragraph 10.2.3.2, "Extended Test Interval," which states:
Test intervals for Type C valves may be increased based upon completion of two consecutive periodic as-found Type C tests where the result of each test is within a licensee's allowable administrative limits.
Elapsed time between the first and last tests in a series of consecutive passing tests used to determine performance shall be 24 months or the nominal test interval (e.g., refueling cycle) for the valve prior to implementing Option B to Appendix J. Intervals for Type C testing may be increased to a specific value in a range of frequencies from 30 months up to a maximum of 75 months. Test intervals for Type C valves should be determined by a licensee in accordance with Section 11.0.
Additional justification for NRC approval of this proposed alternative is provided below:
Although not within the scope of this alternative, separate functional testing of motor operated valve (MOV) PIVs is performed in accordance with ASME OM Code ISTC-3700 Position Verification Testing and stroke-time testing under ISTC-5120 Motor-Operated Valves, which provides additional assurance that these valves will continue to perform their function.
Operators are highly trained to recognize symptoms of the presence of an ISLOCA (i.e., alarms that identify high pressure to low pressure leakage), and to take appropriate actions in accordance with their Emergency Operating Procedures.
Following implementation of this alternative, leakage test intervals will be established based on performance. The leakage test intervals remain consistent with the process established under 10 CFR 50 Appendix J, Option B.
=
Reason for Request===
In its letter dated May 1, 2023, the licensee stated:
In accordance with 10 CFR 50.55a, "Codes and standards," paragraph (z)(1),
"Alternatives to codes and standards requirements," Southern Nuclear Operating Company (SNC) proposes an alternative to the requirements of ASME OM Code Section ISTC-3522, "Category C Check Valves," and Subsection ISTC-3630(a) under Section ISTC-3630, "Leakage Rate for Other Than Containment Isolation Valves," for the subject pressure isolation valves (PIVs) listed in Table 1.
Approval of this alternative will allow PIV testing to be performed at the Vogtle Electric Generating Plant (VEGP) on a performance-based frequency. The proposed 10 CFR 50.55a(z)(1) alternative provides for more efficient plant operation and lower cumulative radiation exposure (CRE), while maintaining an acceptable level of quality and safety.
Since PIVs may or may not be containment isolation valves, they are not necessarily included in scope for performance-based testing, as provided in 10 CFR 50, Appendix J, "Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors," Option B, "Performance-Based Requirements."
The reason for this 10 CFR 50, Appendix J, Option B alternative for containment isolation valve testing is for VEGP to adopt cost effective methods, including the setting of test intervals, for complying with regulatory requirements. Nuclear Energy Institute (NEI) 94-01, "Industry Guideline for Implementing Performance Based Option of 10 CFR 50, Appendix J," Revision 3-A (Reference 1), describes a risk-informed basis for extending containment isolation valve test intervals under Option B. That justification shows that for containment isolation valves which have demonstrated good performance by successful completion of two consecutive leakage rate tests over two consecutive cycles, licensees may increase their test frequencies. Additionally, NEI 94-01 states that if the component does not fail within two operating cycles, further failures appear to be governed by the random failure rate of the component. NEI 94-01 also presents
the results of a comprehensive risk analysis, including the conclusion that risk impact associated with increasing [leak rate] test intervals are negligible (i.e., less than 0.1 percent of total risk).
The proposed performance-based scheduling of PIV tests at VEGP will enable SNC to implement a reduction in the resources required for testing, as well as a reduction in refueling outage duration.
NUREG-0933, "Resolution of Generic Safety Issues," Issue 105, "Interfacing Systems LOCA at LWRs," (Reference 3) discusses the need for PIV leak-rate testing based primarily on three pre-1985 historical failures of applicable valves industrywide. These failures all involved human errors in either operations or maintenance. None of these failures involved inservice equipment degradation.
The performance of PIV leak rate testing provides assurance of acceptable seat leakage with the valve in a closed condition. For check valves, functional testing is accomplished per ASME OM Code ISTC-3522, "Category C Check Valves,"
under ISTC-3520, "Exercising Requirements." Power-operated valves are routinely full stroke tested per ASME OM Code ISTC-5100, Power-Operated Valves, to ensure their functional capabilities. Upon approval of this alternative, the closure functional testing of the PIV check valves will be monitored through a Condition Monitoring Plan in accordance with ISTC-5222, "Condition-Monitoring Program".
The use of a Condition Monitoring Plan is intended to align the frequency for the closure exercise testing with the pressure isolation valve test. By use of a Condition Monitoring Plan, the check valve closure test, based on performance, would be verified concurrently with the PIV seat leakage test. The frequency of the check valve closure test would then be the same as the PIV seat leakage test since closure performance and seat leakage performance are linked. The PIV seat leakage test would not pass if the valve failed to close.
3.2
NRC Staff Evaluation
In Alternative Request ALT-VR-02 (as supplemented), the licensee proposed an alternative to the requirements in ASME OM Code, 2004 Edition through 2006 Addenda, Subsection ISTC, paragraph ISTC-3630(a), for 60 PIVs for the remainder of the fourth 10-year inservice testing program interval at Vogtle, Units 1 and 2. Specifically, the licensee proposes to test and verify the leakage rate of the 60 PIVs using a 10 CFR Part 50, Appendix J, Option B, performance-based schedule. In its submittal describing Alternative Request ALT-VR-02, the licensee provided the current seat leakage testing schedule for these 60 PIVs. Using Alternative Request ALT-VR-02, the PIVs demonstrating good performance for two consecutive cycles may have their test interval extended to every fourth refueling outage [72 months] in lieu of the refueling outage or 2-year interval specified in paragraph ISTC-3630(a). Any PIV leakage test failure will require the leakage testing for the component to return to the initial interval of every refueling outage or 2 years until good performance can again be established.
The PIVs are defined as two valves in series within the reactor coolant pressure boundary that separate the high-pressure RCS from an attached lower pressure system. The failure of a PIV could result in an over-pressurization event which could lead to a system rupture and possible release of fission products to the environment. This type of failure event was analyzed in
NUREG/CR-5928, ISLOCA Research Program, (ML072430731). The purpose of NUREG/CR-5928 was to quantify the risk associated with an ISLOCA event. NUREG/CR-5928 analyzed boiling-water reactor (BWR) and pressurized-water reactor (PWR) designs. The conclusion of the analysis resulted in an ISLOCA not being of concern for PWR designs, such as the PWRs at Vogtle, Units 1 and 2.
The NRC regulations in 10 CFR Part 50, Appendix J, Option B, allow the establishment of a performance-based leakage test program. Guidance for the implementation of acceptable leakage rate test methods, procedures, and analyses for 10 CFR Part 50, Appendix J, Option B, is provided in Regulatory Guide (RG) 1.163, Revision 1, Performance-Based Containment Leak-Test Program (ML23073A154). RG 1.163, Revision 1, endorses the guidance in NEI 94-01, Revision 3-A, with the limitation that Type C component CIVs test intervals may be extended to 75 months with a permissible extension for non-routine emergent conditions of 9 months (84 months total).
RG 1.163, Revision 1, states that licensees planning to use the RG should follow the limitations and conditions identified in the NRC safety evaluation appended to NEI 94-01, Revision 3-A. By letters dated June 8, 2012 (ML121030286) and December 6, 2012 (ML12226A546), the NRC staff found the guidance in NEI 94-01, Revision 3-A, to be acceptable with the following conditions:
[local leakage-rate tests] be increased to 75 months, with a permissible extension (for non-routine emergent conditions) of nine months (84 months total). The staff is allowing the extended interval for Type C LLRTs be increased to 75 months with the requirement that a licensees post-outage report include the margin between the Type B and Type C leakage rate summation and its regulatory limit. In addition, a corrective action plan shall be developed to restore the margin to an acceptable level. The staff is also allowing the non-routine emergent extension out to 84-months as applied to Type C valves at a site, with some exceptions that must be detailed in NEI 94-01, Revision 3. At no time shall an extension be allowed for Type C valves that are restricted categorically (e.g., BWR MSIVs
[main steam isolation valves]), and those valves with a history of leakage, or any valves held to either a less than maximum interval or to the base refueling cycle interval. Only non-routine emergent conditions allow an extension to 84 months.
- 2. The basis for acceptability of extending the ILRT [integrated leak rate testing] interval out to once per 15 years was the enhanced and robust primary containment inspection program and the local leakage rate testing of penetrations. Most of the primary containment leakage experienced has been attributed to penetration leakage and penetrations are thought to be the most likely location of most containment leakage at any time. The containment leakage condition monitoring regime involves a portion of the penetrations being tested each refueling outage, and nearly all LLRTs being performed during plant outages. For the purposes of assessing and monitoring or trending overall containment leakage potential, the as-found minimum pathway leakage rates for the just tested penetrations are summed with the as-left minimum pathway leakage rates for penetrations tested during the previous 1 or 2 or even 3 refueling outages. Type C tests involve valves which, in the aggregate, will show increasing leakage potential due to normal wear and tear, some predictable and some not so predictable. Routine and appropriate maintenance may extend this increasing leakage potential. Allowing for longer intervals between LLRTs means that more leakage rate test results from farther back in time are summed with fewer just tested penetrations and that total used to assess the current containment leakage potential. This leads to the possibility
that the LLRT totals calculated understate the actual leakage potential of the penetrations.
Given the required margin included with the performance criterion and the considerable extra margin most plants consistently show with their testing, any understatement of the LLRT total using a 5-year test interval is thought to be conservatively accounted for.
Extending the LLRT intervals beyond 5 years to a 75-month interval should be similarly conservative provided an estimate is made of the potential understatement and its acceptability determined as part of the trending specified in NEI 94-01, Revision 3, Section 12.1.
When routinely scheduling any LLRT valve interval beyond 60-months and up to 75-months, the primary containment leakage rate testing program trending or monitoring must include an estimate of the amount of understatement in the Type B & C total, and must be included in a licensees post-outage report. The report must include the reasoning and determination of the acceptability of the extension, demonstrating that the LLRT totals calculated represent the actual leakage potential of the penetrations.
The licensee is currently leak testing the 60 PIVs within the scope of Alternative Request ALT-VR-02 every refueling outage or 2 years. The licensee has demonstrated that these PIVs have a history of good performance for eight consecutive refueling outages as shown in Table 2 in Alternative Request ALT-VR-02. The licensee states that the alternative provides for more efficient plant operation and lower cumulative radiation exposure while maintaining an acceptable level of quality and safety. The licensee further stated that eliminating the additional Frequencies would eliminate unnecessary testing, which would reduce occupational radiation exposure and potentially reduce the length of refueling outages. Extending the leakage test interval based on good performance is consistent with a performance-based approach.
In its supplemental letter dated November 17, 2023, the licensee stated that following NRC authorization of Alternative Request ALT-VR-02, CVCM plans will be implemented. Based on its independent review, the NRC staff finds the implementation of CVCM plans will provide reasonable assurance of the functional capability of the check valves within the scope of Alternative Request ALT-VR-02 will be maintained.
Based on the information described above for the 60 PIVs within the scope of Alternative Request ALT-VR-02 for Vogtle, Units 1 and 2, the NRC staff finds that (1) these PIVs have demonstrated good historical performance; (2) no current concerns with the performance of these PIVs have been identified; (3) periodic maintenance activities are not modified by this request; (4) the alternative request allows a performance-based approach for leak testing of these 60 PIVs such that PIVs that have demonstrated good performance for two consecutive cycles may have their test interval extended up to 75 months, with a permissible extension (for non-routine emergent conditions) of 9 months (84 months total); and (5) the alternative request specifies that any PIV leakage test failure would require the component to be returned to the initial ASME OM Code interval until good performance can again be established. Therefore, the NRC staff finds that Alternative Request ALT-VR-02 will implement performance-based leak testing intervals for the PIVs within the scope of this request at Vogtle, Units 1 and 2, that will provide an acceptable level of quality and safety that satisfies 10 CFR 50.55a(z)(1).
4.0 CONCLUSION
As set forth above, the NRC staff has determined that Alternative Request ALT-VR-02 as described in the licensee letters dated May 1, 2023, November 17, 2023, and February 8,
2024, provides an acceptable level of quality and safety for the proposed performance-based leak testing intervals for the specified 60 PIVs at Vogtle, Units 1 and 2, for the remainder of the fourth 10-year IST program interval. Accordingly, the NRC staff concludes that the licensee has adequately addressed the regulatory requirements set forth in 10 CFR 50.55a(z)(1). Therefore, the NRC staff authorizes the use of Alternative Request ALT-VR-02 at Vogtle, Units 1 and 2, for the remainder of the fourth 10-year IST program interval, which is scheduled to end on May 31, 2027.
All other ASME OM Code requirements as incorporated by reference in 10 CFR 50.55a for which relief or an alternative was not specifically requested, and granted or authorized (as appropriate), in the subject request remain applicable.
Principal Contributor: Gurjendra S. Bedi, NRR/DEX/EMIB Thomas G. Scarbrough, NRR/DEX/EMIB Date: April 10, 2024
ML24079A006 NRR-058 OFFICE NRR/DORL/LPL2-1/PM NRR/DORL/LPL2-1/PM NRR/DORL/LPL2-1/LA NRR/DSS/SCPB/BC NAME ZTurner JLamb KGoldstein BWittick DATE 03/18/2024 03/19/2024 03/21/2024 03/28/2024 OFFICE NRR/DEX/EMIB/BC NRR/DORL/LPL2-1/BC NRR/DORL/LPL2-1/PM NAME SBailey MMarkley ZTurner DATE 03/28/2024 04/10/2024 04/10/2024