ML22077A841
| ML22077A841 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 03/24/2022 |
| From: | Jennifer Dixon-Herrity Plant Licensing Branch IV |
| To: | Peters K Vistra Operations Company |
| Galvin D | |
| References | |
| EPID L-2022-LLR-0002 | |
| Download: ML22077A841 (9) | |
Text
March 24, 2022 Mr. Ken J. Peters Senior Vice President and Chief Nuclear Officer Attention: Regulatory Affairs Vistra Operations Company LLC Comanche Peak Nuclear Power Plant 6322 N FM 56 P.O. Box 1002 Glen Rose, TX 76043
SUBJECT:
COMANCHE PEAK NUCLEAR POWER PLANT, UNIT NOS. 1 AND 2 -
PROPOSED ALTERNATIVE SNB-3 FOR THE SNUBBER INSERVICE PROGRAM THIRD INTERVAL EXTENSION (EPID L-2022-LLR-0002)
Dear Mr. Peters:
By [[letter::CP-202100751, (CPNPP) - ASME OM Inservice Test Program Relief Request SNB-3, Snubber Inservice Program Third Internal Extension|letter dated January 4, 2022]], as supplemented by [[letter::CP-202200041, (CPNPP) - Supplement to ASME OM Inservice Test Program Relief Request SNB-3, Snubber Inservice Program Third Interval Extension|letter dated January 27, 2022]], Vistra Operations Company LLC (Vistra OpCo, the licensee), submitted a request to the U.S. Nuclear Regulatory Commission (NRC) for the use of an alternative to certain American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code) requirements at Comanche Peak Nuclear Power Plant, Unit Nos. 1 and 2 (Comanche Peak).
Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR)
Section 50.55a(z)(2), the licensee requested to use the proposed Alternative SNB-3 on the basis that complying with the specified requirement would result in hardship or unusual difficulty.
The licensee requested to extend the Comanche Peak third 10-year inservice examination and testing snubber program by approximately 4 months beyond the OM Code-allowed 1-year extension, from April 19, 2022, to August 2, 2023, to align with the subsequent fourth 10-year inservice testing (IST) program interval for pumps and valves, which begins August 3, 2023.
The NRC staff has reviewed the subject request and concludes, as set forth in the enclosed safety evaluation, that Vistra OpCo has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(z)(2) for proposed Alternative SNB-3. Therefore, the NRC staff authorizes the use of proposed Alternative SNB-3 at Comanche Peak for the third 10-year snubber inservice program interval, which began on April 19, 2012, and is now scheduled to end, with the proposed extension, on August 2, 2023, which is the end date of the third 10-year IST interval.
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.
K. Peters If you have any questions, please contact the project manager, Dennis Galvin, at 301-415-6256 or by e-mail at Dennis.Galvin@nrc.gov.
Sincerely, Jennifer L. Dixon-Herrity, Chief Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-445 and 50-446
Enclosure:
Safety Evaluation cc: Listserv Jennifer L.
Dixon-Herrity Digitally signed by Jennifer L. Dixon-Herrity Date: 2022.03.24 13:06:26 -04'00'
Enclosure SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION PROPOSED ALTERNATIVE SNB-3 TO EXTEND THE SNUBBER INSERVICE PROGRAM THIRD 10-YEAR INTERVAL VISTRA OPERATIONS COMPANY LLC COMANCHE PEAK NUCLEAR POWER PLANT, UNITS NO. 1 AND 2 DOCKET NOS. 50-445 AND 50-446
1.0 INTRODUCTION
By [[letter::CP-202100751, (CPNPP) - ASME OM Inservice Test Program Relief Request SNB-3, Snubber Inservice Program Third Internal Extension|letter dated January 4, 2022]] (Agencywide Documents Access and Management System (ADAMS) Accession No. ML22004A025), as supplemented by [[letter::CP-202200041, (CPNPP) - Supplement to ASME OM Inservice Test Program Relief Request SNB-3, Snubber Inservice Program Third Interval Extension|letter dated January 27, 2022]] (ADAMS Accession No. ML22025A411), Vistra Operation Company, LLC (the licensee),
submitted a request to the U.S. Nuclear Regulatory Commission (NRC) for the use of an alternative to certain American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code) requirements at Comanche Peak Nuclear Power Plant, Unit Nos. 1 and 2 (Comanche Peak, Units 1 and 2).
Specifically, pursuant to Title 10 of the Code of Federal Regulations (10 CFR)
Section 50.55a(z)(2), the licensee requested to use proposed Alternative SNB-3 on the basis that complying with the specified requirement would result in hardship or unusual difficulty. The licensee requested to extend the Comanche Peak, Units 1 and 2, third 10-year snubber inservice examination and testing (inservice) program by approximately 4 months beyond the OM Code-allowed 1-year extension, from April 19, 2022, to August 2, 2023, to align with the subsequent fourth 10-year inservice testing (IST) program interval for pumps and valves, which begins August 3, 2023.
The Comanche Peak, Unit 1 third 10-year inservice inspection (ISI) interval began on August 13, 2010, and ends on August 12, 2022. The extension of the third 10-year interval was verbally authorized by the NRC on August 10, 2020 (ADAMS Accession No. ML20224A055), and documented in a safety evaluation dated January 28, 2021 (ADAMS Accession No. ML21013A128). The Comanche Peak, Unit 1 fourth 10-year ISI interval began on August 13, 2020, and ends on August 12, 2030. The Comanche Peak, Unit 2 third 10-year ISI interval began on August 3, 2013, and ends on August 2, 2023. The Comanche Peak third 10-year IST program interval began on August 3, 2013, and is scheduled to end on August 2, 2023. The Comanche Peak third 10-year snubber inservice program interval began on April 19, 2012, and is scheduled to end on April 19, 2022. The interval dates for the Comanche Peak Units 1 and 2, third 10-year IST program and the third 10-year snubber inservice program were clarified in the supplemental [[letter::CP-202200041, (CPNPP) - Supplement to ASME OM Inservice Test Program Relief Request SNB-3, Snubber Inservice Program Third Interval Extension|letter dated January 27, 2022]].
2.0 REGULATORY EVALUATION
The NRC regulations in 10 CFR 50.55a(g)(4), Inservice inspection standards requirement for operating plants, state, in part, that throughout the service life of a boiling or pressurized water-cooled nuclear power facility, components (including supports) that are classified as ASME Code Class 1, Class 2, and Class 3 must meet the ISI requirements, set forth in Section XI of the editions and addenda of the ASME Boiler and Pressure Vessel Code (ASME BPV Code) or ASME OM Code for snubber examination and testing that become effective subsequent to editions and addenda specified in 10 CFR 50.55a(g)(2) and (3) and that are incorporated by reference in 10 CFR 50.55a(a), to the extent practical within the limitations of design, geometry, and materials of construction of the components.
The NRC regulations in 10 CFR 50.55a(b)(3)(v)(A), Snubbers: First provision, state, in part, that:
Licensees may use Subsection ISTD, Preservice and lnservice Examination and Testing of Dynamic Restraints (Snubbers) in Light-Water Reactor Power Plants, of the ASME OM Code 1995 Edition through the latest edition and addenda incorporated by reference in [10 CFR 50.55a(a)(1)(iv)], in place of the requirements for snubbers in the editions and addenda up to the 2005 Addendum of the ASME BPV Code Section XI.
The NRC regulations in 10 CFR 50.55a(b)(3)(v)(B), Snubbers: Second provision, state that:
Licensees must comply with the provisions for examining and testing snubbers in Subsection ISTD of the ASME OM Code and make appropriate changes to their technical specifications or licensee-controlled documents when using the 2006 Addenda and later editions and addenda of Section XI of the ASME BPV Code.
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) may be used, when authorized by the NRC, if the licensee demonstrates (1) the proposed alternative would provide an acceptable level of quality and safety, or (2) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
Based on the above, and subject to the following technical evaluation, the NRC staff finds that regulatory authority exists for the licensee to request the use of an alternative and the NRC to authorize the use of the proposed alternative.
3.0 TECHNICAL EVALUATION
The information provided by the licensee in support of the request for alternative to ASME OM Code requirements has been evaluated and the bases for disposition are documented below.
3.1 Licensees Proposed Alternative SNB-3 Applicable Code Edition The applicable Code for the Comanche Peak, Unit 1 third 10-year ISI interval; the Comanche Peak, Unit 1 fourth 10-year ISI interval through August 2, 2023; and the Comanche Peak, Unit 2 third 10-year ISI interval is the 2007 Edition through 2008 Addenda of the ASME BPV Code,Section XI. By letter dated June 8, 2020, the NRC staff authorized delaying the update to the Comanche Peak, Unit 1 Code of Record for the fourth 10-year ISI interval until the time of the required Code of Record update for Comanche Peak, Unit 2, on August 3, 2023.
The applicable Code for the third 10-year IST program and the third 10-year snubber inservice program intervals at Comanche Peak, Units 1 and 2, is the 2004 Edition through 2006 Addenda of ASME OM Code.
ASME Code Components Affected Proposed Alternative SNB-3 is for all snubbers within the scope of ASME OM Code, paragraph ISTA-1100, Scope, at Comanche Peak, Units 1 and 2.
=
Applicable Code Requirement===
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 ISTA, paragraph ISTA-3120, Inservice Test Interval, states, in part:
(a)
The frequency for inservice testing shall be in accordance with the requirements of Section IST.
(c)
The inservice test intervals shall comply with the following, except as modified by ISTA-3120(d).
(1)
Initial Test Interval: 10 years following the initial start of unit commercial service.
(2)
Successive Test Intervals: 10 years following the previous test interval.
(d)
Each of the inservice test intervals may be extended or decreased by as much as 1 year. Adjustment shall not cause successive intervals to be altered by more than 1 year from the original pattern of intervals Licensees Reason for Request The Comanche Peak, Units 1 and 2 snubber inservice program examinations and testing are currently performed in accordance with the ASME OM Code, 2004 Edition through the 2006 Addenda, as required by 10 CFR 50.55a(b)(3)(v)(B). This provision requires licensees to comply with the provisions for examining and testing snubbers in Subsection ISTD of the ASME OM Code when using the 2006 Addenda and later editions of ASME BPV Code, Section Xl.
The Comanche Peak, Units 1 and 2 snubber program was transitioned from ASME BPV Code, Section Xl to the ASME OM Code on April 19, 2012, because snubber examination and testing requirements have been deleted from the 2006 Addenda and later editions of the ASME BPV,Section XI. Since this transition occurred separately from an ISI program and IST program interval, the snubber inservice program interval was tracked separately as a stand-alone program.
The licensee is proposing to extend the Comanche Peak, Units 1 and 2, third 10-year snubber inservice program by approximately 4 months beyond the OM Code-allowed 1-year extension, from April 19, 2022, to August 2, 2023, to align with the subsequent fourth 10-year IST program interval for pumps and valves, which begins on August 3, 2023.
The ASME OM Code, paragraph ISTA-3120(d), allows the 10-year IST interval to be extended by as much as 1 year. However, the third 10-year interval for snubber program ends on April 19, 2022. The fourth 10-year IST program for pumps and valves interval start date is August 3, 2023, which is beyond the allowed 1-year extension for the 10-year snubber inservice program. The licensee requested to begin the fourth 10-year IST interval for snubbers on August 3, 2023, to align the snubber program interval with the 10-year IST interval for pumps and valves. The licensee further stated the following in support of the proposed alternative:
The existing snubber [Inservice] program will continue to verify the reliability of the snubber components. Since snubber testing is performed during refueling outages, there will be no changes or lapses in snubber testing activities as a result of extending the interval date to align with the IST Program interval update.
Therefore, the existing snubber program, which is in accordance with the ASME OM Code, 2004 Edition through the 2006 Addenda, will remain in effect until the updated program is implemented on August 3, 2023.
Aligning the [Comanche Peak Units 1 and 2] Snubber Inservice Program interval with the IST program interval will reduce any associated administrative burden and ensures that all IST Code programs (pumps, valves, dynamic restraints) remain in accordance with the same ASME OM Code year and addenda, eliminating any potential for differing governing Code Editions that might arise in subsequent ten-year intervals.
Licensees Proposed Alternative The licensee proposed an alternative to the Comanche Peak, Units 1 and 2, third 10-year inservice examination and testing interval of snubbers duration requirements of ISTA-3120(c)(2) and ISTA-3120(d).
The licensee proposes to extend the Comanche Peak, Units 1 and 2, third 10-year Snubber Inservice Program interval by approximately 4 months beyond the OM Code-allowed 1-year extension, from April 19, 2022, to August 2, 2023. This will allow the alignment of the 10-year snubber inservice program interval and the 10-year IST interval of the pumps and valves, which will result in the sharing of a common inspection and testing interval, and implementing the same ASME OM Code edition during the next (fourth) 10-year IST interval at Comanche Peak, Units 1 and 2.
Proposed Alternative SNB-3 will result in the snubber inservice program continuing to be implemented in accordance with the ASME OM Code 2004 Edition through the 2006 Addenda, until the program is updated as part of the fourth 10-year IST program update on August 3, 2023, at which time the applicable ASME OM Code edition will be implemented.
3.2
NRC Staff Evaluation
Proposed Alternative SNB-3 will synchronize the 10-year interval for snubbers examination and testing with the 10-year IST interval for pumps and valves at Comanche Peak, Units 1 and 2, and result in a common OM Code of Record for the fourth 10-year IST interval program. The NRC staff finds there is an advantage in implementing the same Code requirements at both units for pumps, valves, and snubbers in the same interval. The advantage includes the reduction of administrative burden of maintaining different sets of procedures and requirements and results in a significant decrease in the chance of applying the wrong requirements. The NRC staff considers it a hardship without a compensating increase in the level of quality and safety for the licensee to implement the new OM Code of Record requirements on different dates within a few months for pumps, valves, and snubbers.
In proposed Alternative SNB-3, the licensee stated that the existing snubber program will continue to verify the operational readiness of snubbers in accordance with ASME OM Code, 2004 Edition through 2006 Addenda, and will remain in effect until the updated program is implemented on August 3, 2023. Since snubber testing is performed during refueling outages, there will be no changes or lapses in snubber testing activities as a result of extending the interval dates from April 19, 2022, to August 2, 2023, to align with the 10-year IST interval.
Further, the guidance in NUREG-1482, Guidelines for Inservice Testing at Nuclear Power Plants, Revision 3, dated July 2020 (ADAMS Accession No. ML20202A473), Appendix A, Guidelines for Inservice Examination, Testing, and Service Life Monitoring Program for Dynamic Restraints (Snubbers) at Nuclear Power Plants, Section A.2.6, Snubber Program Plan and its Update Documents, recommends that a plants snubber inservice program be aligned with either the plants ISI program or IST program. Proposed Alternative SNB-3 would align the Comanche Peak, Units 1 and 2, snubber inservice program with the Comanche Peak, Units 1 and 2, IST program.
Based on its review, the NRC staff finds that compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. Further, the NRC staff finds the extension of the 10-year Snubber Inservice Program interval as described in Proposed Alternative SNB-3 is of short duration and the existing snubber program will continue to verify operational readiness of the snubber components, through the extended interval ending August 2, 2023. Therefore, the NRC staff concludes that proposed Alternative SNB-3 will continue to provide an acceptable level of quality and safety during the extended interval.
4.0 CONCLUSION
As set forth above, the NRC staff determined that proposed Alternative SNB-3 for Comanche Peak, Units 1 and 2, provides reasonable assurance that the affected snubber components can perform their safety function. Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(z)(2) for
proposed Alternative SNB-3. Therefore, the NRC staff authorizes the use of the proposed Alternative SNB-3 at Comanche Peak, Units 1 and 2, for the third 10-year snubber inservice program interval, which began on April 19, 2012, and is now scheduled to end, with the proposed extension, on August 2, 2023, which is the end date of the third 10-year IST interval.
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: G. Bedi Date: March 24, 2022
- via e-mail OFFICE NRR/DORL/LPL4/PM NRR/DORL/LPL4/LA*
NRR/DEX/EMIB/BC/(A)*
NAME DGalvin PBlechman ITseng DATE 3/18/2022 3/22/2022 3/17/2022 OFFICE NRR/DORL/LPL4/BC*
NAME JDixon-Herrity DATE 3/24/2022