ML20282A734
| ML20282A734 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 10/22/2020 |
| From: | Dennis Galvin Plant Licensing Branch IV |
| To: | Peters K Vistra Operations Company |
| Galvin D, NRR/DORL/LPL4, 415-6256 | |
| References | |
| EPID L-2020-LLR-0059 [COVID-19] | |
| Download: ML20282A734 (6) | |
Text
COMANCHE PEAK NUCLEAR POWER PLANT, UNIT NO. 2 - PROPOSED ALTERNATIVE TO THE REQUIREMENTS OF THE ASME CODE TO EXTEND THE INSERVICE INSPECTION INTERVAL (EPID L-2020-LLR-0059 [COVID-19])
LICENSEE INFORMATION Licensee:
Vistra Operations Company LLC Licensee Address:
Mr. Ken J. Peters Senior Vice President and Chief Nuclear Officer Attention: Regulatory Affairs Vistra Operations Company LLC Comanche Peak Nuclear Power Plant 6322 North FM 56 PO Box 1002 Glen Rose, TX 76043 Plant Name(s) and Unit(s):
Comanche Peak Nuclear Power Plant, Unit No. 2 Docket No.:
50-446 APPLICATION INFORMATION Submittal Date: April 7, 2020 Submittal Agencywide Documents Access and Management System (ADAMS) Accession No.: ML20099D059 Supplement Date(s): April 10, 2020 Supplement ADAMS Accession No.: ML20101L082 Licensee Proposed Alternative No. or Identifier: 2A3-2 Applicable Regulation: Title 10 of the Code of Federal Regulations (10 CFR),
Section 50.55a(z)(2).
Applicable Code Requirements: American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, inspection schedule requirements for ASME Code Class 1, 2, and 3 components, and their supports, as defined in IWB-2411, IWC-2411, IWD-2411, and IWF-2410, respectively. Further, the ASME Code,Section XI, IWA-2430(c)(3) states: That portion of an inspection interval described as an inspection period may be reduced or extended by as much as 1 year. This adjustment shall not alter the requirements for scheduling inspection intervals.
Applicable Code Edition and Addenda: The 2007 Edition through 2008 Addenda of the ASME Code,Section XI.
Brief Description of the Proposed Alternative:
Proposed Alternative 2A3-2 pertains to volumetric, surface, and/or visual examination of multiple ASME Code Class 1, 2, and 3 welds, welded attachments, and supports at Comanche Peak Nuclear Power Plant, Unit No. 2 (Comanche Peak, Unit 2), as described in Table 1 of the submittal dated April 7, 2020.
At the time of the licensees submittal (April 2020), Comanche Peak, Unit 2 was in the second period of the third inservice inspection (ISI) interval. Completion of the examinations identified in Table 1 is required to meet second period exam completion percentages under the inspection schedule requirements in the ASME Code,Section XI, IWB-2411, IWC-2411, IWD-2411 and IWF-2410. Since the second period of the third ISI interval was scheduled to end on August 3, 2020, the Comanche Peak, Unit 2 spring 2020 refueling outage (2RF18) was the last scheduled opportunity to perform the subject examinations and meet the second period exam completion requirements without an extension to the second inspection period.
The licensee identified that completion of the subject exams for Comanche Peak, Unit 2 during the spring 2020 refueling outage (2RF18) represents a hardship due to the Coronavirus Disease 2019 (COVID-19) pandemic. To minimize the risk of viral transmission to Comanche Peak personnel and the surrounding community, the licensee has to limit the number of supporting contract personnel entering the plant. This includes outside contractor specialists who perform ISI services, and it must implement social distancing between onsite workers.
Also, due to travel restrictions and quarantine requirements associated with COVID-19, the availability of outside contractors to provide the needed inspection services may be limited.
The licensee identified that if it elects to utilize the 1-year inspection period extension allowed by IWA-2430(c)(3), the second period of the third ISI interval could be extended as far out as August 3, 2021. However, since the next refueling outage for Comanche Peak, Unit 2 (2RF19) is scheduled to begin in October 2021, the 1-year period extension allowed by IWA-2430(c)(3) does not provide the flexibility needed to defer the subject exams at Comanche Peak, Unit 2 from the 2RF18 outage in spring 2020 to the 2RF19 outage in fall 2021. Due to the hardship caused by the COVID-19 pandemic, the licensee proposed that the 1-year inspection period extension allowed by IWA-2430(c)(3) be increased to 18 months in accordance with 10 CFR 50.55a(z)(2). The 18-month extension would provide the flexibility needed to defer the second period exams until the 2RF19 refueling outage in fall 2021.
In its basis for use of the proposed alternative, the licensee identified requirements and procedures for leakage monitoring and addressed the favorable inspection history for the subject components. In the supplemental letter, dated April 10, 2020, the licensee provided additional clarifying information regarding the scope of components for the proposed deferral, and the hardship associated with completing VT-3 visual examinations to meet schedule requirements for the second inspection period. This information did not change the scope of the licensees proposed alternative, as documented in its April 7, 2020, submittal.
For additional details on the licensees submittal, and the supplemental information provided in the licensees letter dated April 10, 2020, please refer to the documents located at the ADAMS accession numbers identified above.
REGULATORY EVALUATION Regulatory Basis: 10 CFR 50.55a(z)(2)
Adherence to Section XI of the ASME Code is mandated by 10 CFR 50.55a(g)(4) Inservice inspection standards requirement for operating plants, which states, in part, that ASME Code Class 1, 2, and 3 components, and their supports, must meet the requirements, except the design and access provisions and the pre-service examination requirements, set forth in Section XI of editions and addenda of the ASME Code that are incorporated by reference in 10 CFR 50.55a(a)(1)(ii).
Section 50.55a(z) of 10 CFR, Alternative to codes and standards requirements, states, in part, that alternatives to the requirements of 10 CFR 50.55a(b)-(h) may be used, when authorized by the Director, Office of Nuclear Reactor Regulation, if (1) the proposed alternatives 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.
Pursuant to 10 CFR 50.55a(z)(2), the licensee submitted its proposed alternative on the basis that compliance with the specified requirements of 10 CFR 50.55a would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
TECHNICAL EVALUATION The U.S. Nuclear Regulatory Commission (NRC) staff reviewed the licensees proposed alternative pursuant to 10 CFR 50.55a(z)(2). On April 10, 2020, the NRC staff verbally authorized the use of this alternative (ADAMS Accession No. ML20104A001). In its verbal authorization, the NRC staff determined that the proposed alternative to extend the second inspection period by 6 months beyond the 1-year extension allowed by IWA-2430(c)(3), for a total period extension of 18 months, is technically justified. The NRC staffs written evaluation below documents the technical basis for the NRC's staffs verbal authorization.
Principal plant components addressed by the alternative include the Comanche Peak, Unit 2 pressurizer, Steam Generator No. 2, ASME Code Class 1 piping welds, reactor heat removal Heat Exchanger No. 1, welded attachments, and structural supports. The examinations to be deferred are listed in Table 1 of the submittal dated April 7, 2020; they include 17 ultrasonic volumetric examinations, 9 magnetic particle or dye penetrant surface examinations, and 34 visual examinations by VT-1, VT-2, or VT-3 methods, with the majority being VT-3 examinations. In its supplemental letter dated April 10, 2020, the licensee clarified that any reference to a snubber examination in Table 1 of the submittal includes only that portion of the component support not excluded from the ASME Code,Section XI examination boundary, as defined by ASME Code,Section XI, Figure IWF-1300-1(f).
Reasonable Assurance of Adequate Protection The NRC staff reviewed the information in the submittal dated April 7, 2020, to address how reasonable assurance of adequate protection will be maintained for Comanche Peak, Unit 2, with the deferral of the subject examinations. The NRC staff noted that the licensee will implement the units leakage monitoring program in accordance with plant technical specifications, plant procedures, and administrative controls as described in its submittal. The ability to monitor effectively 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 are deferred. Additionally, visual examinations of borated systems will be performed as part of the licensees boric acid corrosion control program during the current 2RF18 refueling outage.
The NRC staff noted that the licensee reported no unacceptable indications based on the previous exams for the subject components listed in Table 1 of the April 7, 2020, submittal.
Further, based on its independent review of industry operating experience for component aging degradation and considering the various aging effects that may be applicable over the long term, the NRC staff verified that the above components are not prone to the types of aging degradation for which a 6-month extension of the inspection period would prompt a component integrity concern. The NRC staff noted that the second period extension will not impact the completion of all ASME Code,Section XI exams that are required to be completed within the third ISI interval.
Based on the considerations above, the NRC staff determined that the licensees proposal to extend the second inspection period by 6 months beyond the 1-year extension allowed by IWA-2430(c)(3), for a total period extension of 18 months, provides reasonable assurance of adequate protection for the components addressed in the licensees proposed alternative.
Basis for Hardship The NRC staff reviewed the licensees statement of the conditions resulting from COVID-19 that could pose health hazards to personnel if examinations of the subject components were performed during the April 2020 refueling outage to meet period completion schedule requirements. Specifically, the licensee needed to limit the number of personnel entering the site, and it needed to implement social distancing between onsite workers to minimize the risk of viral transmission. The NRC staff acknowledges that these precautions are necessary to protect Comanche Peak personnel who are relied on to safely operate the plant.
The NRC staff determined that the licensees April 7, 2020, submittal, provides sufficient justification for the hardship associated with performing of subject ultrasonic, magnetic particle, and dye penetrant examinations since these exams often require the employment of qualified specialists from outside contractors. With respect to visual exams performed using the VT-3 method, the NRC staff reviewed the supplemental statements provided in the licensees April 10, 2020, supplemental letter. The licensees supplement identifies that the hardship of performing the VT-3 visual exams listed in Table 1 of the submittal is related to the availability of VT-3-qualified technicians. The ASME Code,Section XI, IWA-2300 provides specific qualification requirements for personnel performing inservice examinations. The licensee identified that Comanche Peak has traditionally relied on contracted personnel, rather than plant personnel, to perform the VT-3 exams as part of its ISI program. The contracted personnel are very proficient and accustomed to performing VT-3 exams for ISI purposes, whereas the limited number of VT-3-qualified plant personnel are quality control inspectors. The licensee noted that the quality control inspectors are relied on to support other outage activities.
The NRC staff reviewed the licensees statements and acknowledged that there is a hardship associated with performing the subject VT-3 exams since outside specialists must also be brought in to perform these exams. The NRC staff identified that bringing in additional personnel to perform the subject examinations increases the risk of viral transmission and is contrary to federal guidelines for protecting workers from viral transmission. The NRC staff also acknowledges that, due to travel restrictions, this pandemic has resulted in uncertainty that the appropriate ISI specialists would even be available to perform the subject examinations during the April 2020 refueling outage.
As the ongoing COVID-19 pandemic is of sufficient severity and magnitude to warrant an emergency determination under Section 501(b) of the Robert T. Stafford Disaster Relief and Emergency Assistance Act, 42 U.S.C. Sections 5121-5207, and the U.S. Centers for Disease Control and Prevention has determined that COVID-19 poses a serious public health risk, the NRC staff finds that the licensees hardship justification is acceptable.
In summary, considering that reasonable assurance of adequate protection will be maintained for the subject components, the NRC staff determined that performing the subject examinations to meet ASME Code,Section XI schedule requirements for completion of second period exams would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
CONCLUSION As discussed above, the NRC staff has determined that complying with the subject requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. Further, the licensees proposed alternative provides reasonable assurance of adequate protection for the subject components. The NRC staff concludes that the licensee has adequately addressed the regulatory requirements in 10 CFR 50.55a(z)(2).
Therefore, the NRC staff authorizes the use of the proposed Alternative 2A3-2 for Comanche Peak, Unit 2 until completion of the next refueling outage, currently scheduled for October 2021, but no longer than 6 months beyond the 1-year inspection period extension allowed by IWA-2430(c)(3).
All other ASME Code,Section XI requirements for which an alternative was not specifically requested and approved in this proposed alternative remain applicable, including third-party review by the Authorized Nuclear Inservice Inspector.
Principal Contributor(s): Christopher Sydnor Stephen Cumblidge Date: October 22, 2020 Jennifer L. Dixon-Herrity, Chief Plant Licensing Branch 4 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Jennifer L.
Dixon-Herrity Digitally signed by Jennifer L. Dixon-Herrity Date: 2020.10.22 13:06:16 -04'00'
- by email OFFICE NRR/DORL/LPL4/PM NRR/DORL/LPL4/LA*
NRR/DNRL/NVIB/BC*
NAME DGalvin PBlechman HGonzalez DATE 10/21/2020 10/21/2020 9/14/2020 OFFICE NRR/DNRL/NPHP/BC*
NRR/DORL/LPL4/BC*
NAME MMitchell JDixon-Herrity DATE 9/14/2020 10/22/2020