ML23038A183

Request for Additional Information Alternative Request (RA-22-0174) to Use ASME Code Case N-752

ML23038A183
Person / Time
Site:	Oconee
Issue date:	02/07/2023
From:	Shawn Williams Plant Licensing Branch II
To:	Treadway R Duke Energy Carolinas
Williams S
References
EPID L-2022-LLR-0060
Download: ML23038A183 (4)

Text

From: Shawn Williams To: Treadway, Ryan I Cc: Vaughan, Jordan L

Subject:

Oconee Nuclear Station, Units 1, 2, and 3 - Request for Additional Information RE: Alternative Request (RA 0174) to use ASME Code Case N-752 Date: Tuesday, February 07, 2023 1:40:00 PM Attachments: Oconee RAIs for Alternative Request to use CC-752.docx

Dear Mr. Treadway,

By letter dated July 27, 2022, Duke Energy Carolinas, LLC, (Duke Energy) submitted an alternative request for Oconee Nuclear Station, Units 1, 2, and 3, and the Keowee Hydro Station, Units 1 and 2. Duke Energy is requesting to use the alternative requirements of American Society of Mechanical Engineers (ASME) Code Case N-752, Risk-Informed Categorization and Treatment for Repair/Replacement Activities in Class 2 and 3 SystemsSection XI, Division 1, for determining the risk-informed categorization and for implementing alternative treatment for repair/replacement activities on moderate and high energy Class 2 and 3 items in lieu of certain ASME Code Section XI, paragraph IWA-1000, IWA-4000, and IWA-6000 requirements. Duke Energy submitted the request pursuant to Section 50.55a(z) (1) of Title 10 of the Code of Federal Regulations, which requires the applicant to demonstrate that the proposed alternative would provide an acceptable level of quality and safety.

The U.S. Nuclear Regulatory Commission (NRC) staff has determined that additional information is needed as discussed in the enclosure. A clarification call to ensure mutual understanding was conducted on February 6th, 2023.

Please respond within 30 days of the date of this e-mail.

If you have any questions, please contact me at 301-415-1009 or via e-mail at Shawn.Williams@nrc.gov.

Sincerely, Shawn A. Williams, Senior Project Manager Plant Licensing Branch, II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-269, 50-270, and 50-287

Enclosure:

Request for Additional Information cc w/encl: Listserv

REQUEST FOR ADDITIONAL INFORMATION ALTERNATIVE REQUEST (RA-22-0174) TO USE ASME CODE CASE N-752 OCONEE NUCLEAR STATION UNITS 1, 2 AND 3 DUKE ENERGY CAROLINAS, LLC DOCKET NOS. 50-269, 50-270 AND 50-287 Background to RAIs No. 1 - 5 In its letter dated July 27, 2022 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML22208A031), the licensee states that Code Case N-752 is based on the ANO-2 [Arkansas Nuclear One, Unit 2] relief request (ANO2-R&R-004, Revision 1), and authorized in NRC safety evaluation dated April 22, 2009 (ML090930246). The licensee further states that the ANO-2 relief request was developed to serve as an industry pilot for developing a risk-informed repair/replacement. In Section 5.2.B. of its submittal, the licensee states that:

The categorization process of Code Case N-752 is delineated in Appendix I of the Code Case. This categorization process is technically identical to the process approved by the NRC under Relief Request ANO2-R&R-004, Revision 1 (Reference 8.8), which, in turn, is based on founding principles in

[Electric Power Research Institute] EPRI Report TR-112657, Revision B-A, Revised Risk-Informed Inservice Inspection Evaluation Procedure, and the categorization process of Code Case N-660, but with improvements and lessons learned from trial applications.

RAI No. 1 Section 3.5.1. of the EPRI report contains the definition of piping segment consisting of four criteria. The EPRI report is referenced in CC N-752 without a clear reference to whether the definition of piping segment is used.

a. Explain how the piping segments are defined in the licensees proposed alternative, that is in accordance with CC N-752.

b. If the definition is different from that which is described in EPRI TR 112657, provide an evaluation and justification for any deviations in the definition of piping segments for Code Case N-752 from N-660, or from ANO-2 R&R-004.

RAI No. 2 Code Case N-752 specifies corrective actions for those structures, systems and components (SSCs) which have been categorized low safety significance (LSS). Describe how corrective actions will be programmatically addressed, including deviations from these program requirements.

Enclosure

RAI No. 3 In Section 5.2.F of the proposed alternative, the licensee states that categorization and treatment requirements of Code Case N-752 applicable to repair/replacement activities are consistent with NRC requirements specified in 10 CFR 50.69.

Discuss all deviations in categorization of SSCs from the 10 CFR 50.69 risk-informed categorization program and the licensees proposed alternative, that is in accordance with Code Case N-752. Discuss why any deviations are acceptable in accordance with 10 CFR 50.55a(z).

RAI No. 4 NRC Safety Evaluation for Relief Request ANO2-R&R-004 states, in part, that:

Entergyhas requested to categorize passive SSCs (e.g., piping) and implement alternative special treatment activities limited to the repair/replacement activities for Class 2 and 3 pressure retaining items or their associated supports a) Describe how the licensees application of Code Case N-752 in the proposed alternative aligns or deviates from the intent of the statement above.

b) If the licensees use of Code Case N-752 allows categorization of components with active functions, describe how those components are evaluated for categorization and provide justification that active components are not categorized solely based on their pressure retaining function.

RAI No. 5 The ANO2-R&R-004 LAR (ML071150108) states the following:

This process shall be applied on a system basis, including pressure-retaining items and their associated supports within the selected system.

Entergy will define the boundaries included in the scope of the RISC evaluation process consistent with the previously approved [risk-informed inservice inspection] (RI-ISI) application.

a) Describe how the licensees application of Code Case N-752 in the proposed alternative aligns or deviates from the intent of the statements above.

b) If the licensees use of Code Case N-752 deviates from the scope as defined above, provide justification for how the evaluation process sufficiently captures impacts from unanalyzed components within a system.

RAI No. 6 Section 5.2.E.14 states, in part, that As permitted by Code Case N-752, Duke Energy intends to implement the QA Program exemption applicable to IWA-1400(n) and IWA-4000 when performing repair/replacement activities on LSS items. That said, this code case exemption only applies if compliance with 10 CFR 50, Appendix B, or NQA-1 is not required by the NRC at the

Owners facility. To address this issue, Duke Energy will update the Fleet Quality Assurance Program Description (QAPD) for safety-related Class 2 and 3 SSCs identified as LSS in accordance with ASME Code Case N-752 to not be required to meet the requirements of the QAPD.

In accordance with 10 CFR 50.54(a), when the use of a quality assurance exception is approved by an NRC safety evaluation, licensees may make changes to a previously accepted quality assurance program description without prior NRC approval provided the bases of the approval are applicable to the licensees facility. Any deviations from the original approved wording in the safety evaluation approving the QAPD change may result in a reduction in commitment that must be submitted to the NRC for review and approval under 10 CFR 50.54(a)(4).

Provide the proposed update to Duke Energys QAPD to ensure consistency with the NRCs previously approved QAPD change for Entergy in conjunction with their request for Arkansas Nuclear One to adopt ASME Code Case N-752.

Request for Confirmation of Information (RCI) No. 1 In Section 5.2.E.12 of the proposed alternative, the licensee states that Conditions that would prevent a LSS item from performing its safety-related function(s) under design basis conditions will be corrected in a timely manner.

Confirm that for those SSC under 10 CFR 50.36, Technical Specifications, they will be addressed within the timeline of the limiting conditions of operability or the necessary action statements will be performed.