ML22039A339
| ML22039A339 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 03/03/2022 |
| From: | James Danna NRC/NRR/DORL/LPL1 |
| To: | Stoddard D Dominion Energy Nuclear Connecticut |
| Guzman R | |
| References | |
| EPID L-2021-LLR-0018 | |
| Download: ML22039A339 (10) | |
Text
March 3, 2022
Mr. Daniel G. Stoddard Senior Vice President and Chief Nuclear Officer Dominion Energy Nuclear Connecticut, Inc.
Millstone Power Station Innsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711
SUBJECT:
MILLSTONE POWER STATION, UNIT NO. 3 - REQUEST FOR ALTERNATIVE FREQUENCY TO SUPPLEMENTAL VALVE POSITION VERIFICATION TESTING REQUIREMENTS IN THE FOURTH 10-YEAR VALVE INSERVICE TESTING PROGRAM (EPID L-2021-LLR-0018)
Dear Mr. Stoddard:
By letter dated March 24, 2021 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML21084A239), as supplemented by letter dated July 26, 2021 (ADAMS Accession No. ML21209A762), Dominion Energy Nuclear Connecticut, Inc. (the licensee) submitted alternative request V-01 to the U.S. Nuclear Regulatory Commission (NRC) regarding specific inservice testing (IST) program requirements of American Society of Mechanical Engineers (ASME) Operation and Maintenance (OM) of Nuclear Power Plants, 2012 Edition, ISTC-3700 as incorporated by reference in Title 10 of the Code of Federal Regulations (10 CFR) 50.55a for the fourth 10-year IST program interval at Millstone Power Station, Unit No. 3 (Millstone 3).
Specifically, pursuant to 10 CFR 50.55a(z)(1), the licensee proposed an alternative to the provisions of ISTC-3700 to allow utilization of the containment local leak rate testing (LLRT) frequency requirement, such that the scheduled LLRT will satisfy the applicable requirements on the basis that the alternative provides an acceptable level of quality and safety. The NRC staff has completed its review of the licensee's request and finds that the proposed alternative request V-01 provides an acceptable level of quality and safety for the fourth 10-year IST program interval.
Accordingly, the NRC staff concludes that the li censee has adequately a ddressed the regulatory requirements set forth in 10 CFR 50.55a(z)(1). Therefore, the NRC authorizes the use of proposed alternative request V-01 for the fourth 10-Year IST program interval at Millstone 3, which began on December 2, 2018, and will end December 28, 2028.
All other ASME Code,Section XI, requirements for which relief was not specifically requested and authorized herein by the NRC staff remain applicable, including third-party review by the Authorized Nuclear lnservice Inspector.
D. Stoddard
If you have any questions, please contact the Millstone project manager, Richard Guzman, at 301-415-1030 or by e-mail to Richard.Guzman@nrc.gov.
Sincerely,
James G. Danna, Chief Plant Licensing Branch I Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
Docket No. 50-423
Enclosure:
Safety Evaluation
cc: Listserv
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION
ALTERNATIVE REQUEST V-01 FOR THE
FOURTH 10-YEAR INTERVAL VALVE INSERVICE TESTING PROGRAM
DOMINION ENERGY NUCLEAR CONNECTICUT, INC.
MILLSTONE POWER STATION, UNIT 3
DOCKET NO. 50-423
1.0 INTRODUCTION
By letter dated March 24, 2021 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML21084A239), as supplemented by letter dated July 26, 2021 (ADAMS Accession No. ML21209A762), Dominion Energy Nuclear Connecticut, Inc. (the licensee) submitted alternative request V-01 to the U.S. Nuclear Regulatory Commission (NRC) regarding specific inservice testing (IST) program requirements in the 2012 Edition of the American Society of Mechanical Engineers (ASME) Operation and Maintenance of Nuclear Power Plants, Division 1, OM Code: Section IST (OM Code) as incorporated by reference in Title 10 of the Code of Federal Regulations (10 CFR) 50.55a for the fourth 10-year IST program interval at Millstone Power Station, Unit 3 (Millstone 3).
Specifically, pursuant to 10 CFR 50.55a(z)(1), the licensee proposed an alternative to the provisions of ISTC-3700 to allow utilization of the containment local leak rate testing (LLRT) frequency requirement, such that the scheduled LLRT will satisfy the applicable requirements on the basis that the alternative provides an acceptable level of quality and safety. The NRC describes its review of alternative request V-01 for Millstone 3 in this safety evaluation (SE).
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 (BPV Code)
Class 1, Class 2, or Class 3 may be satisfied as an augmented IST program in accordance with
Enclosure
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 may be acceptable provided the basis for deviations from the ASME OM Code, as incorporated by reference in 10 CFR 50.55a, 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(b)(3)(xi), OM condition: Valve Position Indication, state the following:
When implementing paragraph ISTC-3700, Position Verification Testing, in the ASME OM Code, 2012 Edition through the latest edition and addenda of the ASME OM Code incorporated by reference in paragraph (a)(1)(iv) of this section, licensees shall verify that valve operation is accurately indicated by supplementing valve position indicating lights with other indications, such as flow meters or other suitable instrumentation to provide assurance of proper obturator position for valves with remote position indication within the scope of Subsection ISTC including its mandatory appendice s and their verification methods and frequencies.
The NRC regulations in 10 CFR 50.55a(z), Alternatives to codes and standards requirements, state, in part, that alternatives to the requirements of 10 CFR 50.55a(b) through (h) 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 following request is a proposed alternative in lieu of certain IST program requirements of the 2012 Edition of the ASME OM Code as incorporated by reference in 10 CFR 50.55a for the IST program at Millstone 3 described in the fourth 10-year IST program interval.
3.2 Licensees Alternative Request V-01
The IST requirements of the ASME OM Code 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-3530, Valve Obturator Movement, states that:
The necessary valve obturator movement shall be determined by exercising the valve while observing an appropriate indicator, such as indicating lights that signal the required changes of obturator position, or by observing other evidence, such as changes in system pressure, flow rate, level, or temperature, that reflects change of obturator position.
ASME OM Code, Subsection ISTC, paragraph ISTC-3700, Position Verification Testing, states, in part, that:
Valves with remote position indicators shall be observed locally at least once every 2 yr [years] to verify that valve operation is accurately indicated. Where practicable, this local observation should be supplemented by other indications such as use of flow meters or other suitable instrumentation to verify obturator position. These observations need not be concurrent. Where local observation is not possible, other indications shall be used for verification of valve operation.
In its submittal, the licensee requests alternative testing for the following 19 valves:
Table 1: Scope of Valves ASME OM Valve ID/ Valve Description Code Valve Operator Class Category 3CMS*CTV20 CTMT ATMOSPHERE Pneumatic MONITOR SUCTION, CTMT 2 A PENETRATION (32-OUTSIDE) 3CMS*CTV21 CTMT ATMOSPHERE Pneumatic MONITOR SUCTION, CTMT 2 A PENETRATION (32-OUTSIDE) 3CMS*CTV23 CTMT ATMOSPHERE Pneumatic MONITOR DISCHARGE, CTMT 2 A PENETRATION(63-OUTSIDE) 3CVS*AOV23 CTMT VACUUM EJECTOR Pneumatic SUCTION ISOL VLV, CTMT 2 A PENETRATION (37-INSIDE) 3CVS*CTV20A CTMT VACUUM PUMP Pneumatic SUCTION, CTMT ISOLATION 2 A PENETRATION (35-OUTSIDE) 3CVS*CTV20B CTMT VACUUM PUMP Pneumatic SUCTION, CTMT ISOLATION 2 A PENETRATION (36-OUTSIDE)
ASME OM Valve ID/ Valve Description Code Valve Operator Class Category 3CVS*CTV21A CTMT VACUUM PUMP Pneumatic SUCTION, CTMT ISOLATION 2 A PENETRATION (35-OUTSIDE) 3CVS*CTV21B CTMT VACUUM PUMP Pneumatic SUCTION, CTMT ISOLATION PENETRATION (36-OUTSIDE) 2 A 3CVS*MOV25 CTMT VACUUM PUMP Motor DISCHARGE, CTMT 2 A PENETRATION (121-INSIDE) 3DAS*CTV24 Pneumatic RX PLANT AERATED DRAINS, CTMT PENETRATION (28-INSIDE) 2 A 3DAS*CTV25 Pneumatic RX PLANT AERATED DRAINS, CTMT PENETRATION (28-OUTSIDE) 2 A 3DGS*CTV24 PRT & CTMT DRAINS Pneumatic TRANSFER PP DSCHRG, CTMT 2 A PENETRATION (27-INSIDE) 3DGS*CTV25 PRT & CTMT DRAINS TRNSFR Pneumatic PP DSCHRGE, CTMT 2 A PENETRATION (27-OUTSIDE) 3HCS*V002 OBA HYDROGEN Manual RECOMBINER SUPPLY, CTMT 2 A PENETRATION (111-OUTSIDE) 3HCS*V003 OBA HYDROGEN Manual RECOMBINER SUPPLY, CTMT 2 A PENETRATION (111-OUTSIDE)
DBA HYDROGEN 3HCS*V006 RECOMBINER DISCHARGE, Manual CTMT PENETRATION (113-2 A OUTSIDE) 3HCS*V009 DBA HYDROGEN Manual RECOMBINER SUPPLY, CTMT 2 A PENETRATION (112-OUTSIDE) 3HCS*V010 DBA HYDROGEN Manual RECOMBINER SUPPLY, CTMT 2 A PENETRATION (112-OUTSIDE)
DBA HYDROGEN 3HCS*V013 RECOMBINER DISCHARGE, Manual CTMT PENETRATION (114-2 A OUTSIDE)
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Reason for Request===
In its submittal dated March 24, 2021, as supplemented by letter dated July 26, 2021, the licensee stated that it utilizes procedures dev eloped for the containment LLRT program per 10 CFR Part 50, Appendix J, Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors, to help satisfy the supplemental position verification testing of valve closure
for the 19 valves listed in Table 1 of this SE. The licensee is performing these activities as part of meeting the valve position indication testing requirements specified in paragraph ISTC-3700 of ASME OM Code, Subsection ISTC. Paragraph ISTC-3700 of the ASME OM Code, Subsection ISTC, requires obturator testing more frequently than the individual LLRT Type C tests required by 10 CFR Part 50, Appendix J. The licensee proposes an alternative to the provisions of paragraph ISTC-3700 to allow utilization of the LLRT test frequency requirement, such that the scheduled LLRT will satisfy the requirements for both ISTC-3700 valve position indication testing and individual valve 10 CFR Part 50, Appendix J, Type C LLRT.
Proposed Alternative
In its submittal dated March 24, 2021, as supplemented by letter dated July 26, 2021, the licensee proposes to perform the supplemental indication test requirement of 10 CFR 50.55a(b)(3)(xi) at frequencies consistent with the 10 CFR Part 50, Appendix J, Option B, Type C program for the 19 valves listed in Table 1 of this SE.
The NRC regulations in 10 CFR 50.55a(b)(3)(xi) state that licensees shall verify that valve operation is accurately indicated by supplementing valve position indicating lights with other indications, such as flow meters or other suitable instrumentation, to provide assurance of proper obturator position. Paragraph ISTC-3700 of ASME OM Code, Subsection ISTC, states that supplemental valve position verification shall be observed at least once every 2 years. For certain valves at Millstone 3, meeting the quantified valve leakage acceptance criteria of 10 CFR Part 50, Appendix J, Type C testing (LLRT) can be credited to meet the supplemental position verification closure testing portion of the requirement. By License Amendment No. 276 dated July 15, 2020 (ADAMS Accession No. ML20161A000), the licensee adopted the Appendix J, Performance-Based, Option B, Program consistent with Nuclear Energy Institute (NEI) 94-01, Revision 3-A, Industry Guideline for Implementing Performance Based Option of 10 CFR Part 50, Appendix J, for Millstone 3 (ADAMS Accession No. ML12221A202). This program allows LLRT intervals to be extended up to 75 months for valves with a history of satisfactory testing.
For the 19 valves in Table 1 of this SE, the licensee states that a frequency of every 2 years is retained for open supplemental valve position verification testing. Additionally, the licensee considered that the alternative request does not change the frequency of ISTC-3700 position indication testing in either the open or closed direction. The NRC staff discusses this licensee position in Section 3.3 below.
3.3 NRC Staff Evaluation
The licensee has proposed an alternative test in lieu of the requirements in ASME OM Code, Subsection ISTC, paragraphs ISTC-3530 and ISTC-3700, for the valves listed in Table 1 of this SE. Specifically, the licensee proposes to perform the supplemental position verification testing required by 10 CFR 50.55a(b)(3)(xi) in conjunction with the Type C tests (which measure containment isolation valve leakage rates) at a frequency in accordance with the 10 CFR Part 50, Appendix J, Option B, schedule. The applicable valves would initially be tested at the required interval schedule, which is currently every 2 years, as specified by paragraph ISTC-3700. Valves that have demonstrated good performance for two consecutive cycles may have their test interval extended to a maximum of 75 months. Any position indication testing
failure would require the component to return to the initial interval of every 2 years until good performance can again be established.
By License Amendment No. 276, the licensee received approval to amend the technical specifications to implement a performance-based leakage-testing program in accordance with the 10 CFR Part 50, Appendix J, Option B,, schedule using the guidance of NEI 94-01, Revision 3-A (License Amendment No. 27. This amendment increased the Type C test interval to 75 months. The performance-based leakage-testing program under 10 CFR Part 50, Appendix J, Option B,, requires individual containment isolation valves to be good performers before they can be placed on the extended seat leakage testing frequency. The valves in Table 1 of this SE have met the performance standard for extension to a 75-month period, with only two exceptions (3CMS*CTV21 and 3CVS*AOV23). The licensee reviewed the maintenance and Code-required performance history to verify that the valves listed in Table 1 have been reliable. The licensee adopted ASME OM Code, 2012 Edition, for the fourth 10-Year IST Program interval at Millstone 3 in December 2018. The valves listed in Table 1 have met the applicable ASME OM Code requirements. The licensees review of recorded performance history for the valves in Table 1, which dated back to 1985, identified no stem-to-disc separation events.
Verification of the flow through the valves every 2 years coupled with a supplemental leak rate test at a 10 CFR Part 50, Appendix J, Option B, test interval demonstrates that valve operation is accurately indicated and provides an acceptable alternative to the 2-year frequency required by paragraph ISTC-3700 of the OM Code, Subsection ISTC. The NRC staff considers extension of the valve close function leakage test interval based on good performance is a logical progression as part of a performance-based program.
In discussing its alternative request, the licensee considered the valve position indication test required by paragraph ISTC-3700 and the supplemental requirement specified in 10 CFR 50.55a(b)(3)(xi) to be separate tests. However, the NRC regulations in 10 CFR 50.55a(b)(3)(xi) state that when implementing ASME OM Code, 2012 Edition, ISTC-3700, licensees shall verify that valve operation is accurately indicated by supplementing valve position indicating lights with other indications, such as flow meters or other suitable instrumentation, to provide assurance of proper obturator position. The Federal Register notice dated July 18, 2017 (82 FR 32934, 32950-32951) specified that the NRC was adding 10 CFR 50.55a(b)(3)(xi) to emphasize the provisions in OM Code, 2012 Edition, ISTC-3700, to verify that valve obturator position is accurately indicated. Therefore, the valve position indication test required by ISTC-3700 as supplemented by 10 CFR 50.55a(b)(3)(xi) is a single test.
Based on the information described above for the 19 valves in Table 1 of this SE, the NRC staff finds that (1) previous IST testing including position verification testing for these valves indicates the valves acceptable historical performance; (2) no current concerns with the performance of these valves have been identified; (3) periodic maintenance activities are not modified by this request; and (4) the alternative provides an acceptable level of quality and safety for the extension of the valve position indication testing interval requested in the licensees submittal.
4.0 CONCLUSION
As set forth above, the NRC staff finds that proposed alternative request V-01 for the 19 valves listed in Table 1 of this SE will provide an acceptable level of quality and safety for the fourth 10-Year IST program interval, which began on December 2, 2018, and will end December 28, 2028. 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 authorizes the use of proposed alternative request V-01 at Millstone 3 for the fourth 10-Year IST program interval.
All other ASME Code requirements for which relief or an alternative was not specifically requested, and granted or authorized (as appropriate), in the subject request remain applicable.
Principal Contributors: T. Scarbrough Y. Wong
Date: March 3, 2022
ML22039A339 OFFICE NRR/DORL/LPL1/PM NRR/DORL/LPL1/LA NRR/DEX/EMIB/BC NAME RGuzman KEntz ITseng DATE 2/8/2022 2/9/2022 11/3/2021 OFFICE NRR/DORL/LPL1/BC NRR/DORL/LPL1/PM NAME JDanna RGuzman DATE 3/3/2022 3/3/2022