ML23073A368

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Authorization and Safety Evaluation for Proposed Alternative I6R-10, Revision 0 Related to the Steam Generators,
ML23073A368
Person / Time
Site: Ginna Constellation icon.png
Issue date: 03/16/2023
From: Hipolito Gonzalez
NRC/NRR/DORL/LPL1
To: Rhoades D
Constellation Energy Generation, Constellation Nuclear
References
EPID L-2021-LLR-0092
Download: ML23073A368 (1)


Text

March 16, 2023 R. E. GINNA NUCLEAR POWER PLANT - AUTHORIZATION AND SAFETY EVALUATION FOR PROPOSED ALTERNATIVE I6R-10, REVISION 0 RELATED TO THE STEAM GENERATORS (EPID L-2021-LLR-0092)

LICENSEE INFORMATION Recipients Name and Address: Mr. David P. Rhoades Senior Vice President Constellation Energy Generation, LLC President and Chief Nuclear Officer Constellation Nuclear 4300 Winfield Road Warrenville, IL 60555 Licensee: Constellation Energy Generation, LLC (CEG)

Plant Name and Unit: R. E. Ginna Nuclear Power Plant (Ginna)

Docket No.: 50-244 APPLICATION INFORMATION Submittal Date: December 14, 2021, and Supplement dated March 1, 2023 Submittal Agencywide Documents Access and Management System (ADAMS)

Accession No.: ML21348A078, ML23060A162 Applicable Inservice Inspection (ISI) Program Interval: The applicable ISI program interval is listed in the following table.

Plant ISI Interval Start Date End Date Ginna Sixth January 1, 2020 December 31, 2029 Alternative Provision: The applicant requested an alternative under Title 10 of the Code of Federal Regulations (10 CFR), paragraph 50.55a(z)(2).

ISI Requirements: For American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME BPV Code) Category C-A steam generator welds, ASME Code,Section XI, Subparagraph IWC-2411(a) and Table IWC-2411-1, require a minimum percentage of required inspections be conducted within period 1 of an ASME Code interval. These inspections are required by ASME Code,Section XI, Table IWC-2500-1 (C-A), for each ISI interval.

Applicable Code Edition and Addenda: The applicable ASME BPV Code,Section XI, edition is listed in Table 1.

Table 1: Applicable ASME Code,Section XI Editions Plant Edition Ginna 2013 Edition Brief Description of the Proposed Alternative: The licensee proposed to achieve less than the ASME Code, Table IWC-2411-1, required examination percentage for the first period of the current Sixth ISI Interval. The licensee referenced an extended description of the associated hardship from letter dated February 21, 2023 (ML23052A068).

STAFF EVALUATION The U.S. Nuclear Regulatory Commission (NRC) staff reviewed the referenced description of hardship provided in the March 1, 2023, letter. The NRC staff finds that requiring the licensee to meet the ASME Code,Section XI, subparagraph IWC-2411(a), and Table IWC-2411-1, minimum inspections requirements would result in non-negligible setup costs and some dose.

This is compounded by additional costs associated with having to schedule the appropriate personnel and equipment for an imminent outage. The licensee noted that potential alternatives to the subject inspections are currently under NRC staff review and that they had scheduled their activities based on an initial estimate of this review time.

The NRC staff reviewed the general operating history of the subject C-A steam generator welds and found that these welds have a strong operating history. The staff further reviewed the plant-specific history of the subject C-A steam generator welds and found that no recordable indications have been identified in the subject welds during multiple intervals of previous ISI inspections. In addition, there is no currently known active degradation mechanism in the subject welds such that a one-time alternative to the Table IWC-2411-1 requirements at a single unit for a single period would lead to an undue increase in risk.

The NRC staff determined that the likelihood of an unknown degradation mechanism having gone undetected and/or initiating; and a flaw resulting from this degradation mechanism growing to sufficient size to threaten the integrity of the subject welds before the next inspection is acceptably low based on the limited application and duration of this alternative request. The NRC staff further noted that it is the rarity of approvals of similar requests that underpins the determination that this approval does not constitute an undue increase in risk (and consequently is not associated with a compensating increase in the level of quality and safety).

The NRC staff noted that scheduling resources based on the expectation of NRC review schedules is an enterprise risk decision on the part of the licensee. However, the NRC staff finds that, based on the above discussion, compliance with ASME Code,Section XI, IWC-2411(a) and Table IWC-2441-1 for a single period constitutes a hardship without commensurate increase in quality and safety. Therefore, the staff finds that the applicants basis for requesting an alternative based on hardship as set forth in 10 CFR 50.55a(z)(2) is acceptable because of the reasons discussed above.

CONCLUSION The NRC staff determined that compliance with the specified requirements results in a hardship or unusual difficulty without a compensating increase in quality or safety.

The NRC staff concludes that the licensee has adequately addressed the regulatory requirements set forth in 10 CFR 50.55a(z)(2).

The NRC staff authorizes the use of proposed alternative I6R-10, Rev.0, at Ginna for the Sixth ISI interval for the first period.

All other ASME BPV Code,Section XI, requirements for which an alternative was not specifically requested and authorized remain applicable, including third-party review by the Authorized Nuclear Inservice Inspector.

Principal Contributor: Dan Widrevitz Date: March 16, 2023 Digitally signed by Hipolito Hipolito J. J. Gonzalez Date: 2023.03.16 Gonzalez 09:13:19 -04'00' Hipólito J. González, Chief Plant Licensing Branch LPL1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation cc: Listserv

ML23073A368 OFFICE NRR/DNRL/NVIB NRR/DORL/LPL1/LA NRR/DNRL/NVIB/BC NAME DWidrevitz KZeleznock (KEntz for) ABuford DATE 3/13/2023 3/15/2023 3/13/2023 OFFICE NRR/DORL/LPL1/PM NRR/DORL/LPL1/BC NAME VSreenivas HGonzález DATE 3/16/2023 3/16/2023