ML20224A055
| ML20224A055 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 08/10/2020 |
| From: | Dennis Galvin NRC/NRR/DORL/LPL4 |
| To: | Hicks J Luminant Generation Co |
| References | |
| L-2020-LLR-0092, L-2020-LLR-0093, L-2020-LLR-0094 | |
| Download: ML20224A055 (8) | |
Text
From:
Galvin, Dennis Sent:
Monday, August 10, 2020 3:33 PM To:
Jack Hicks (Jack.Hicks@luminant.com)
Cc:
Mitchell, Matthew; Gonzalez, Hipo; Dixon-Herrity, Jennifer; Barnette, James
Subject:
Verbal Authorization of Comanche Peak Unit 1 Relief Requests 1A3-2, 1A4-1, and 1A4-2 (L-2020-LLR-0092 to L-2020-LLR-0094)
Attachments:
L-2020-LLR-0092 Comanche Peak Unit 1 COVID ISI Deferral Verbal Authorization 2020-08-10.pdf; L-2020-LLR-0093 -94 Comanche Peak Unit 1 COVID BMI and CRDM ISI Alternative Verbal Authorization 2020-08-10.pdf
- Jack, Please find the attached Jack, written documentation of the verbal authorizations Comanche Peak Unit 1 Relief Request Relief Requests 1A3-2, 1A4-1, and 1A4-2. Relief Request 1A3-2 is addressed in the first attachment. Relief Requests 1A4-1 and 1A4-2 are addressed in the second attachment.
If you have any questions, please contact me at (301) 415-6256 or Dennis.Galvin@nrc.gov.
Respectfully, Dennis Galvin Project Manager U.S Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Division of Operating Reactor Licensing Licensing Project Branch 4 301-415-6256 Docket No. 50-445
Hearing Identifier:
NRR_DRMA Email Number:
713 Mail Envelope Properties (SA9PR09MB55196C95E0BA6859BF43ADCFFB440)
Subject:
Verbal Authorization of Comanche Peak Unit 1 Relief Requests 1A3-2, 1A4-1, and 1A4-2 (L-2020-LLR-0092 to L-2020-LLR-0094)
Sent Date:
8/10/2020 3:32:30 PM Received Date:
8/10/2020 3:32:00 PM From:
Galvin, Dennis Created By:
Dennis.Galvin@nrc.gov Recipients:
"Mitchell, Matthew" <Matthew.Mitchell@nrc.gov>
Tracking Status: None "Gonzalez, Hipo" <Hipolito.Gonzalez@nrc.gov>
Tracking Status: None "Dixon-Herrity, Jennifer" <Jennifer.Dixon-Herrity@nrc.gov>
Tracking Status: None "Barnette, James" <James.Barnette@luminant.com>
Tracking Status: None "Jack Hicks (Jack.Hicks@luminant.com)" <Jack.Hicks@luminant.com>
Tracking Status: None Post Office:
SA9PR09MB5519.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 664 8/10/2020 3:32:00 PM L-2020-LLR-0092 Comanche Peak Unit 1 COVID ISI Deferral Verbal Authorization 2020-08-10.pdf 109153 L-2020-LLR-0093 -94 Comanche Peak Unit 1 COVID BMI and CRDM ISI Alternative Verbal Authorization 2020-08-10.pdf 83736 Options Priority:
Normal Return Notification:
No Reply Requested:
No Sensitivity:
Normal Expiration Date:
VERBAL AUTHORIZATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION 10 CFR 50.55A PROPOSED ALTERNATIVE 1A3-2 TO DEFER AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME) CODE INSERVICE INSPECTIONS DUE TO PANDEMIC (COVID-19)
COMANCHE PEAK NUCLEAR POWER PLANT, UNIT 1 VISTRA OPERATIONS COMPANY LLC DOCKET NO. 50-445 Technical Evaluation Read by Matthew Mitchell, Chief of the Piping and Head Penetration Branch, Office of Nuclear Reactor Regulation and Hipolito Gonzalez, Chief of the Vessels and Internals Branch, Office of Nuclear Reactor Regulation By electronic submission dated July 14, 2020 (Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML20196L829 and ML20196L824), Vistra Operations Company LLC (the licensee) requested an alternative to the inservice inspection (ISI) requirements of ASME Code,Section XI. Alternative 1A3-2 pertains to the volumetric and/or surface examination of multiple ASME Code Class 1 and 2 component welds at Comanche Peak, Unit 1, as described in Table 1 of the submittal. Plant component examinations addressed by the alternative include volumetric examinations of welds in control rod drive housings and one instrument nozzle housing; volumetric and/or surface examinations of secondary side steam generator shell welds, nozzle welds, and one nozzle inner radius; and volumetric examination of one pressurizer nozzle-to-vessel weld. The subject examinations must be completed within the Comanche Peak, Unit 1 third ISI interval.
Pursuant to Title 10 of the Code of Federal Regulations (10 CFR) Section 50.55a(z)(2), the licensee requested NRC authorization of its proposed alternative to extend its third ISI interval for the subject component examinations listed in Table 1 by twelve months beyond the interval extension allowed by ASME Code,Section XI. The licensee requested this alternative on the basis that compliance with the ASME Code schedule requirement results in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
The third ISI interval for Comanche Peak, Unit 1 began on August 13, 2010, and was originally scheduled to end on August 12, 2020. To allow sufficient time for the completion of the subject examinations during its 1RF21 refueling outage, scheduled for October 18, 2020, the licensee has implemented the one-year ISI interval extension allowed by the ASME Code,Section XI, Subparagraph IWA-2430(c)(1) - this permits the licensee to extend its third ISI interval until no later than August 12, 2021. Since the third interval must now end by August 12, 2021, the licensees 1RF21 refueling outage, scheduled for October 18, 2020, is the last opportunity to perform the subject examinations in accordance with ASME Code,Section XI schedule requirements.
The licensee described how completion of the subject exams during its 1RF21 outage would result in significant hardship. The licensee reported that the hardship is caused by potential spread of the COVID-19 virus to Comanche Peak personnel and the surrounding community, as well as travel restrictions and quarantine requirements affecting the availability of outside contractors to assist with the subject examinations. The licensee identified that, after the 1RF21 refueling outage, the next opportunity to perform the subject exams is the 1RF22 refueling outage, which is currently scheduled for April 17, 2022. The 1-year extension allowed by IWA-2430(c)(1) does not permit the subject exams to be deferred from 1RF21 to 1RF22.
Accordingly, the licensee has requested that the NRC authorize its proposed alternative to
extend the third ISI interval by an additional twelve months, until August 2022, for the subject examinations.
The NRC staff identified that, due to the COVID-19 pandemic, the licensee will need to limit the number of personnel entering the Comanche Peak site during the October 2020 refueling outage, and it needs to implement social distancing between onsite workers to minimize the risk of viral transmission. The staff acknowledges that these precautions are necessary to protect Comanche Peak personnel who are relied on to safely operate the plant. Requiring the licensee to complete these examinations during the October 2020 refueling outage to meet ASME Code schedule requirements is contrary to federal guidelines for protecting workers from viral transmission.
In addition, the licensee provided information regarding how reasonable assurance of adequate protection will be maintained for Comanche Peak, Unit 1 with the deferral of the subject examinations. The licensee will implement the units leakage monitoring program in accordance with plant Technical Specifications, procedures, and administrative controls, as described in its submittal. The ability to effectively monitor for leakage during the upcoming operating cycle will provide for the prompt identification, investigation, and mitigation of leakage to maintain the integrity of the pressure boundary components for which examinations were deferred.
Additionally, visual examinations of borated systems will be performed in accordance with the licensees boric acid corrosion control program during the upcoming 1RF21 refueling outage, currently scheduled for October 18, 2020.
The staff noted that the licensee reported no unacceptable indications based on the previous exams for the subject components listed in Table 1 of the submittal. Further, based on its independent review of industry operating experience for component aging degradation, and considering potential applicability of long term aging effects, the NRC staff verified that the above components are not prone to the types aging degradation for which an additional 12-month extension of the ISI interval, until August 2022 for the subject examinations, beyond that allowed by ASME Code would prompt a component integrity concern.
Therefore, based on the above, the NRC staff finds that (1) there is reasonable assurance that the licensees proposed alternative has a minimal impact on safety; and (2) the licensees hardship justification is acceptable.
CONTACTS: Chris Sydnor, NRR/DNRL/NVIB and Roger Kalikian, NRR/DNRL/NPHP Authorization read by Jennifer Dixon-Herrity, Chief of the Plant Licensing Branch IV, Office of Nuclear Reactor Regulation As Chief of the Plant Licensing Branch IV, Office of Nuclear Reactor Regulation, I agree with the conclusions of the Vessels and Internals Branch and the Piping and Head Penetrations Branch.
The NRC staff concludes that the proposed inspection deferral for Comanche Peak, Unit 1 will provide reasonable assurance of adequate safety for the subject components identified in Table 1 of the licensees July 14, 2020, electronic submittal until the next refueling outage currently scheduled for April 17, 2022, when the ASME Code-required inservice examination of the subject components will be performed. The NRC staff finds that complying with the inspection schedule requirements of the ASME Code,Section XI, as mandated by 10 CFR 50.55a, would result in hardship or unusual difficulty without a compensating increase in the level of quality
and safety. 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 deferral of these examinations.
Therefore, effective August 10, 2020, the NRC authorizes the use of the proposed alternative at Comanche Peak, Unit 1 until completion of the refueling outage 1RF22, currently scheduled for the Spring of 2022.
All other requirements in ASME Code,Section XI for which relief was not specifically requested and approved in this relief request remain applicable, including third-party review by the Authorized Nuclear Inservice Inspector.
This verbal authorization does not preclude the NRC staff from asking additional clarification questions regarding the proposed relief while subsequently preparing the written safety evaluation.
VERBAL AUTHORIZATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION 10 CFR 50.55A PROPOSED ALTERNATIVES 1A4-1 AND 1A4-2 REGARDING AUGMENTED INSERVICE INSPECTIONS DUE TO PANDEMIC (COVID-19)
COMANCHE PEAK NUCLEAR POWER PLANT, UNIT 1 VISTRA OPERATIONS COMPANY LLC DOCKET NO. 50-445 Technical Evaluation read by Matthew Mitchell, Chief of the Piping and Head Penetration Branch, Office of Nuclear Reactor Regulation By electronic submissions dated July 14, 2020 (Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML20196L827 and ML20196L828), and as supplemented on August 5, 2020 (ADAMS No. ML20218A863), Vistra Operations Company LLC (the licensee), requested alternatives to some of the augmented inservice inspection (ISI) program requirements of Title 10 of the Code of Federal Regulations (10 CFR) 50.55a(g)(6)(ii).
Proposed Alternatives 1A4-1 and 1A4-2 address inspection requirements for reactor pressure vessel (RPV) head control rod drive mechanism (CRDM) nozzle penetrations and RPV bottom mounted instrument (BMI) nozzle penetrations, respectively, at Comanche Peak Nuclear Power Plant (Comanche Peak), Unit 1.
Pursuant to 10 CFR 50.55a(z)(2), the licensee requested NRC authorization of its proposed alternatives on the basis that compliance with these requirements will result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
The licensee described how completion of the subject exams during its 1RF21 outage would result in significant hardship. The licensee reported that the hardship is caused by potential spread of the COVID-19 virus to Comanche Peak personnel and the surrounding community, as well as travel restrictions and quarantine requirements affecting the availability of outside contractors to assist with the subject examinations. The licensee has requested NRC approval for a delay of bare metal visual examinations (VEs) required by 10 CFR 50.55a(g)(6)(ii) due to the hardship caused by potential spread of the COVID-19 virus. The NRC staff identified that, due to the COVID-19 pandemic, the licensee will need to limit the number of personnel entering the Comanche Peak site during the October 2020 refueling outage, and the need to implement social distancing between onsite workers to minimize the risk of viral transmission. The staff acknowledges that these precautions are necessary to protect Comanche Peak personnel who are relied on to safely operate the plant. Therefore, NRC staff finds that the licensees hardship justification is acceptable.
The licensee is requesting to delay the bare metal VE for the CRDM nozzles from refueling outage 1RF21 to refueling outage 1RF23. The licensee has proposed deferral to 1RF23 because of currently scheduled volumetric examinations for the CRDM nozzles during the outage for 1RF22. However, in the event that the currently scheduled volumetric examinations are not performed during 1RF22, the licensee will perform the required bare metal VE in 1RF22.
As a compensatory measure for not conducting a bare metal VE meeting the requirements of Code Case N-729-4, the licensee will perform a boric acid examination of the head by observing the flange area and inspecting underneath the CRDM cooling shroud support ring gap, looking for signs of boric acid leakage during 1RF21 and 1RF22, if VEs are not performed in 1RF22.
The licensee is requesting to delay the required BMI nozzle bare metal VE from refueling outage 1RF21 to refueling outage 1RF22. As a compensatory measure for not conducting the required bare metal VE per Code Case N-722-1, the licensee will perform a VE of the bottom head from the edge of the RPV lower head mirror insulation package by removal of selected insulation panels to gain access which will allow examinations for signs of boric acid leakage.
In addition to the compensatory VEs, the licensee stated that the units leakage monitoring program in accordance with plant Technical Specifications, procedures, and administrative controls provides the ability to monitor for leakage effectively during the deferral period(s) and will provide for the prompt identification, investigation, and mitigation of potential leakage to maintain the integrity of the pressure boundary components for which examinations were deferred.
Based on the information provided above, the NRC staff finds that there is reasonable assurance of adequate protection based on:
x The compensatory VEs of the RPV upper and bottom heads conducted during the deferral period. Additionally, if the RPV upper head VEs will be deferred to 1RF23, the licensee will perform volumetric examinations in 1RF22.
x The operating experience of primary water stress corrosion cracking (PWSCC)-resistant RPV upper head penetrations and prior bare metal examinations of lower head BMI nozzles.
x The licensees leakage monitoring with the capability of detecting 0.1 gallons per minute (gpm) of unidentified leakage and the administrative controls used to detect signs of leakage.
Therefore, based on the above, the NRC staff finds that (1) there is reasonable assurance that the licensees proposed alternative has a minimal impact on safety; and (2) the licensees hardship justification is acceptable.
Authorization read by Jennifer Dixon-Herrity, Chief of the Plant Licensing Branch IV, Office of Nuclear Reactor Regulation As Chief of the Plant Licensing Branch IV, Office of Nuclear Reactor Regulation, I agree with the conclusions of the Piping and Head Penetrations Branch.
The NRC staff concludes that the proposed inspection deferrals and alternatives for Comanche Peak, Unit 1 during the upcoming 1RF21 outage, currently scheduled to begin October 18, 2020, will provide reasonable assurance of adequate safety for the upper head CRDM nozzles and the lower head BMI nozzles. The NRC staff finds that complying with the inspection schedule requirements of ASME Code Cases N-729-4 and N-722-1, as mandated by 10 CFR 50.55a(g)(6)(ii), would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. 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 deferral of these examinations.
Therefore, effective August 10, 2020, the NRC authorizes the use of the proposed alternatives 1A4-1 and 1A4-2 at Comanche Peak, Unit 1 until completion of the refueling outage 1RF22 for alternative 1A4-2, and outages 1RF22 and 1RF23 for alternative 1A4-1 currently scheduled for the Spring of 2022 and Fall of 2023, respectively.
All other requirements in ASME Code,Section XI for which relief was not specifically requested and approved in this relief request remain applicable, including third-party review by the Authorized Nuclear Inservice Inspector.
This verbal authorization does not preclude the NRC staff from asking additional clarification questions regarding the proposed relief while subsequently preparing the written safety evaluation.
Principal contributors: