ML25209A549
| ML25209A549 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 07/28/2025 |
| From: | Byrd T NRC/NRR/DORL/LPL4 |
| To: | Dewhirst L Nebraska Public Power District (NPPD) |
| Wengert T, NRR/DORL/LPLIV, 415-4037 | |
| References | |
| EPID L-2025-LLR-0035 | |
| Download: ML25209A549 (1) | |
Text
From:
Thomas Byrd To:
Dewhirst, Linda R.
Subject:
Cooper - REQUEST FOR ADDITIONAL INFORMATION RELIEF REQUEST RS-01 (EPID L-2025-LLR-0035)
Date:
Monday, July 28, 2025 2:07:00 PM Attachments:
RAI-10603-R1-FINAL.docx image001.png By letter dated March 4, 2025 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML25065A116), Nebraska Public Power District (the licensee) submitted request to the U.S. Nuclear Regulatory Commission (NRC) for authorization to perform alternative to specific inservice testing (IST) requirements in the 2022 Edition of the American Society of Mechanical Engineers (ASME) Operation and Maintenance of Nuclear Power Plants, Division 1, OM Code: Section IST (OMCode) as incorporated by reference in Title 10 of the Code of Federal Regulations (10 CFR), Section 50.55a, Codes and standards.
The alternative request RS-01 pertains to the inservice testing of various snubbers at Cooper Nuclear Station (CNS) for Code Of Record (COR) Interval Program which is schedule to start on March 1, 2026.
The 2022 Edition of the ASME OM Code is incorporated by reference in 10 CFR 50.55a(a)(1)
(iv) and thus forms part of the applicable Code of Record for the Cooper Nuclear Station IST program. RS-01, Section 7, Precedents states that RS-01 submittal dated June 16, 2021 (ML21167A098) was previously approved for the final portion of the fifth 10-year at CNS as RS-01 (EPID L-2021-LLR-0044), dated July 21, 2022 (ML22200A277). NRC staff observed that the prior approval of RS-01 was based on the use of ASME Code Case OMN-13, now incorporated in ASME OM Code-2022, Subsection ISTD.
The NRC staff has reviewed the information provided and determined that additional information is required in order to complete the review and approval of the changes. The Nuclear Regulatory Commission (NRC) staff reviewed the submittal and determined that additional information, as described in the attached draft request for additional information (RAI), is required for the staff to complete its review of the application. This RAI is identified as a draft currently to confirm your understanding of the information that the NRC staff needs to complete the evaluation. Please let me know if you would like to have a call with the NRC staff to clarify this request. If the request for information is understood, response to this RAI is due September 8, 2025, 30 days after issuance of this letter.
If you have any questions, please feel free to contact me.
Thomas Byrd Project Manager - Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation OWFN 08F10
1 REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION COOPER - RELIEF REQUEST IST ASME 2022 - RS-01 NEBRASKA PUBLIC POWER DISTRICT COOPER, UNIT 1 DOCKET NO. 05000298 ISSUE DATE: 07/28/2025
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Background===
By letter dated March 4, 2025 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML25065A116), Nebraska Public Power District (the licensee) submitted request to the U.S. Nuclear Regulatory Commission (NRC) for authorization to perform alternative to specific inservice testing (IST) requirements in the 2022 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), Section 50.55a, Codes and standards.The alternative request RS-01 pertains to the inservice testing of various snubbers at Cooper Nuclear Station (CNS) for Code Of Record (COR) Interval Program which is schedule to start on March 1, 2026.
The 2022 Edition of the ASME OM Code is incorporated by reference in 10 CFR 50.55a(a)(1)(iv) and thus forms part of the applicable Code of Record for the Cooper Nuclear Station IST program. RS-01, Section 7, Precedents states that RS-01 submittal dated June 16, 2021 (ML21167A098) was previously approved for the final portion of the fifth 10-year at CNS as RS-01 (EPID L-2021-LLR-0044), dated July 21, 2022 (ML22200A277). NRC staff observed that the prior approval of RS-01 was based on the use of ASME Code Case OMN-13, now incorporated in ASME OM Code-2022, Subsection ISTD.
Regulatory Basis Regulatory Basis:
The NRC regulations in 10 CFR 50.55a(f)(4), Inservice testing standards requirement for operating plants, state, in part:
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 inservice test 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 paragraphs (f)(2) and (3) of this section [10 CFR 50.55a] and that are incorporated by reference in paragraph (a)(1)(iv) of this section [10 CFR 50.55a], to the extent practical within the limitations of design, geometry, and materials of construction of the components.
The NRC may grant relief and may impose alternative requirements pursuant to paragraph 10 CFR 50.55a(f)(6)(i). In requesting relief under 10 CFR 50.55a(f)(5)(iii), the licensee must demonstrate that conformance is impractical for its facility.
Additionally, the NRC regulations in 10 CFR 50.55a(z), Alternatives to codes and standards requirements, state:
2 Alternatives to the requirements of paragraphs (b) through (h) of this section 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.
RAI Verification of Applicability of Previous RS-01 Snubber Information RS-01, Section 7, Precedents, states that the RS-01 submittal dated June 16, 2021 (ML21167A098), was previously approved for the final portion of the fifth 10-year IST interval at Cooper Nuclear Station (CNS) under EPID L-2021-LLR-0044, with NRC approval documented on July 21, 2022 (ML22200A277). The NRC staff notes that this prior approval was based on the use of ASME Code Case OMN-13, which has since been incorporated into the ASME OM Code 2022 Edition, Subsection ISTD.
Please confirm that the information and details related to mechanical and hydraulic snubbers provided in the October 12, 2021, RAI responses (ML21285A286) remain valid and applicable to the current Alternative Request RS-01 under the 2022 Edition of the ASME OM Code.
Additionally, identify any changes to the safety-related snubber population since the previous IST interval, including any additions, removals, or replacements of snubbers.
RAI Snubber Service Life Maintenance under ISTD-6200, Snubber Service Life and Expiration Dates, of the October 12, 2021, RAI responses provided service life information for all safety-related mechanical and hydraulic snubbers. The NRC staff notes that the service life of 62 mechanical snubbers expired in 2022 or 2024, and 35 mechanical snubbers are projected to expire in 2026.
Pursuant to ASME OM Code 2022 Edition, paragraph ISTD-6200, Service Life Reevaluation, please describe the specific actions taken to maintain or extend the service life of these mechanical snubbers. Specifically, indicate whether:
Service life extensions were formally evaluated and approved under CNS procedures; The affected snubbers were replaced, rebuilt, or refurbished; Condition monitoring or other activities were used to support the continued operability of the snubbers.
Include a summary of the technical basis and documentation controls applied to ensure compliance with ISTD-6200.
RAI Justification for Extension of 10-Year Visual Examination Grace Period to 120 Days
3 For the fifth 10-year IST interval, the NRC previously approved Alternative Request RS-01 to allow a 90-day grace period for the 10-year visual examination of snubbers in accordance with ASME Code Case OMN-13. In the current request, CNS proposes to extend this grace period to 120 days under the ASME OM Code 2022 Edition, which incorporates the provisions of OMN-13 under ISTD-4253 and Table ISTD-4252-1, Note 7.
Please provide the technical basis and justification for the proposed 120-day grace period.
Specifically:
Explain how this proposed interval aligns with plant outage scheduling and campaign-based visual examination practices; Provide relevant plant-specific snubber performance history; Include any industry operating experience, vendor recommendations, or condition monitoring insights that support this extension; Demonstrate how the proposed alternative continues to provide an acceptable level of quality and safety consistent with the requirements of 10 CFR 50.55a(z)(1).
RAI Snubber Failure History Since June 16, 2021 Please identify any instances of snubber visual examination failures and/or functional test failures that have occurred since June 16, 2021. For each occurrence:
Describe the nature of the failure (e.g., type, location, failure mode);
Summarize corrective actions taken; Identify any preventive measures implemented to ensure continued reliability of the affected snubber population.
This information is requested to support the NRC staffs evaluation of the ongoing effectiveness of the CNS snubber program under the current Code of Record.
OFFICE NRR/DORL/LPL4/PM NRR/DORL/LPL4/BC NRR/DEX/EMIB/BC NAME TByrd TNakanishi TScarbrough DATE 07/28/2025 07/24/2025 07/23/2025