ML23279A208
| ML23279A208 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 10/05/2023 |
| From: | Turner Z Plant Licensing Branch II |
| To: | Pournaras D Southern Nuclear Operating Co |
| References | |
| EPID L-2023-LLA-0061, EPID L-2023-LLR-0023 | |
| Download: ML23279A208 (1) | |
Text
From: Zach Turner To: Pournaras, DeLisa S.
Cc: Ed Miller; John Lamb; Lowery, Ken G.; Chamberlain, Amy Christine
Subject:
Formal Issuance of RAIs for Vogtle Units 1 and 2 LAR and Proposed Alternative Request related to TS 3.4.14 Date: Thursday, October 5, 2023 2:18:00 PM Attachments: Vogtle 1 2 RAIs related to LAR to Change TSSR 3.4.14.1 PIVs.pdf Vogtle 1 2 RAIs related to PIVs RR ALT-VR-02.pdf
- DeLisa, By letter dated May 1, 2023 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML23121A267), Southern Nuclear Operating Company (SNC, the licensee) submitted a license amendment request (LAR) and a proposed alternative request for Vogtle Electric Generating Plant (Vogtle), Units 1 and 2.
The proposed change would revise Technical Specification (TS) 3.4.14, RCS Pressure Isolation Valve (PIV) Leakage and Surveillance Requirement (SR) 3.4.14.1 to only require testing at the frequencies specified in the Inservice Testing Program in accordance with the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance (OM) of Nuclear Power Plants. This would effectively remove PIV testing at 18month, nine month, and event based frequencies to conform with the ASME OM 2year testing on applicable Vogtle PIVs. Additionally, SNC proposed an alternative to the requirements of ASME OM Code Section ISTC3522, Category C Check Valves, and Subsection ISTC3630(a) under Section ISTC3630, Leakage Rate for Other Than Containment Isolation Valves, for applicable Vogtle PIVs to allow testing to be conducted at a performancebased frequency, as specified in Nuclear Engineering Institute 9401, Revision 3A.
The NRC staff reviewed the submittal dated May 1, 2023, and determined that additional information is needed to complete its review.
On September 7, 2023, the NRC staff provided draft RAI questions to SNC to make sure that the RAI is understandable, the regulatory basis is clear, to ensure there is no proprietary information, and to determine if the information was previously docketed. On October 2, 2023, a clarifying call was held between the NRC staff and SNC, and SNC stated that it would provide the RAI response within 45 days from the date of this email.
The RAIs for Vogtle, Units 1 and 2 LAR and proposed alternative request are attached to this email and are released formally with a 45-day response period (November 20, 2023) requested.
If you have any questions, you can contact me at 301-415-2258.
Very Respectfully, Zach Turner, Project Manager Nuclear Regulatory Commission Division of Operating Reactor Licensing NRR/DORL/LPL2-1
(301) 415-2258 Office: OWFN-07C12 Mail Stop: O-08 B01A
REQUEST FOR ADDITIONAL INFORMATION LICENSE AMENDMENT REQUEST TO REVISE TECHNICAL SPECIFICATION SURVEILLANCE REQUIREMENT 3.4.14.1 SOUTHERN NUCLEAR OPERATING COMPANY VOGTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2 DOCKET NOS. 50-424 AND 50-425 EPID: L-2023-LLA-0061
References:
- 1. Southern Nuclear Operating Company (SNC, the licensee) submitted a license amendment request (LAR) to revise Technical Specification (TS) Surveillance Requirement (SR) 3.4.14.1 and Enclosure 2, Proposed Inservice Testing (IST) Alternative Request ALT-VR-02 for Vogtle Electric Generating Plant , Units 1 and 2 (VEGP), by letter dated May 1, 2023, to the U.S. Nuclear Regulatory Commission (NRC) (Agencywide Documents Access and Management System Accession No. ML23121A267).
- 2. Vogtle Electric Generating Plant - Units 1 and 2, Fourth 10-Year Interval lnservice Testing Program Update, dated October 23, 2017 (ML17298A197).
EMIB-LAR-RAI-1 In the submitted LAR for VEGP, Enclosure 1, Section 1.1, Summary Description, states in part, that the proposed amendment would revise Technical Specification (TS) 3.4.14, RCS Pressure Isolation Valve (PIV) Leakage, Surveillance Requirement (SR) 3.4.14.1, to only require testing at the frequencies specified in the Inservice Testing (IST) Program. Attachment 4 of the submittal provides a list of all the PIVs in the scope of this LAR. The NRC staff reviewed the PIVs listed in and VEGP Units 1 and 2 IST Program Plan, and found the following apparent discrepancies:
VEGP Units 1 and 2 IST Program Plan includes the following PIVs to be tested at frequencies as specified by TS SR 3.4.14.1.
1/2-1204-U6-079 1/2-1204-U6-083 1/2-1204-U6-080 1/2-1204-U6-084 1/2-1204-U6-081 1/2-1204-U6-085 1/2-1204-U6-082 1/2-1204-U6-086 For other PIVs included in the LAR (Attachment 4), the VEGP IST Program Plan requires leakage tests without specifying TS SR 3.4.14.1 for the following valves:
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1/2-HV-8701A/B 1/2-HV-8702A/B 1/2-1204-U4-143 1/2-1204-U6-147 1/2-1204-U4-144 1/2-1204-U6-148 1/2-1204-U4-145 1/2-1204-U6-149 1/2-1204-U4-146 1/2-1204-U6-150 1/2-1204-U4-120 1/2-1204-U4-121 1/2-1204-U4-123 1/2-1204-U4-122 Please provide the following information:
- a. Clarify the apparent discrepancy of the leakage testing of PIVs between the LAR, Attachment 4, and VEGP IST Program Plan (ML17298A197) as specified above.
- b. Clarify if the IST Program will be updated based on the above.
- c. Clarify if the TS SR 3.4.14.1 requirement will be deleted from the VEGP IST Program Plan after approval of this LAR.
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REQUEST FOR ADDITIONAL INFORMATION ALTERNATIVE REQUEST ALT-VR-02 FOURTH 10-YEAR 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
References:
- 1. Southern Nuclear Operating Company (SNC, the licensee) submitted a license amendment request (LAR) to revise Technical Specification (TS) Surveillance Requirement (SR) 3.4.14.1 and Enclosure 2, Proposed Inservice Testing (IST) Alternative Request ALT-VR-02 for Vogtle Electric Generating Plant, Units 1 and 2, by letter dated May 1, 2023, to the U.S. Nuclear Regulatory Commission (NRC) (Agencywide Documents Access and Management System Accession No. ML23121A267).
- 2. Vogtle Electric Generating Plant - Units 1 and 2, Fourth 10-Year Interval lnservice Testing Program Update, dated October 23, 2017 (ML17298A197).
EMIB-RAI-1 Alternative Request ALT-VR-02, Section 4.0, Reason for Change, on page E-2-2, first and second paragraph, states, in part, that:
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.
Since pressure isolation valves (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, 1
Appendix J, Revision 3-A (Reference 1), describes a risk-informed basis for extending containment isolation valve test intervals under Option B.
ASME OM Code, Subsection ISTC, paragraph ISTC-3630, Leakage Rate for other than Containment Isolation Valves, requires that ASME OM Code Category A Valves with leakage requirements not based on an Owners 10 CFR Part 50, Appendix J Program shall be tested to verify their seat leakage within the acceptable limits.
The NRC staff approved the use of NEI 94-01, Revision 3-A, with conditions (ML12226A546) for PIVs other than containment isolation valves (CIVs) testing intervals in lieu of the ASME OM Code, Subsection ISTC, paragraph ISTC-3630(a) requirement of at least once every 2 years.
- a. As described in the first paragraph of Section 4.0 above, explain whether Alternative Request ALT-VR-02 for ASME OM Code, Subsection ISTC, paragraph ISTC-3630, includes any PIVs that are CIVs.
- b. As described in the first and second paragraphs of the Section 4.0 above, explain how Alternative Request ALT-VR-02 for use of NEI 94-01 for PIVs is applicable to any CIVs in the request.
EMIB-RAI-2 Alternative Request ALT-VR-02, Section 4.0, Reason for Request, on page E-2-3, last two paragraphs, state, in part, that:
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.
The licensee states that upon approval of this alternative, the closure functional testing of the PIV check valves will be monitored through a Conditioning Monitoring Plan in accordance with ASME OM Code, Subsection ISTC, paragraph ISTC-5222. Please explain the following:
- a. Vogtle 1 and 2 Fourth 10-Year IST Program Plan dated October 23, 2017, (ML17298A197) indicates that the PIV check valves included in Alternative Request ALT-VR-02 are already included in a Condition Monitoring Program. Explain the statement that the PIV check valves will be monitored through a Condition Monitoring Plan.
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- b. Explain the implementation of the provisions in ASME OM Code, Appendix II, Check Valve Condition Monitoring Program, for the PIV check valves at Vogtle Units 1 and 2.
EMIB-RAI-3 Alternative Request ALT-VR-02, Section 5.0, Proposed Alternative and Basis for Use, fourth paragraph, on page E-3-3, states, in part, that:
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.
Explain how the Condition Monitoring Program interval as specified in Table II-4000-1, Maximum Intervals for Use When Applying Interval Extensions, of ASME OM Code, Appendix II, will align with the NEI 94-01 interval if the alternative is authorized by NRC.
EMIB-RAI-4 Alternative Request ALT-VR-02, Section 7.0, Precedent, lists several alternatives recently authorized by the NRC staff for licensees of other nuclear power plants that are said to have used a similar approach to Alternative Request ALT-VR-02 for Vogtle Units 1 and 2. Describe any differences in the provisions of Alternative Request ALT-VR-02 for Vogtle Units 1 and 2 in comparison to the most recent alternative (River Bend) authorized by the NRC staff in 2022.
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