Information Notice 2025-01, Lessons Learned with Implementing ASME Code Case N-752

Lessons Learned with Implementing ASME Code Case N-752

ML24323A057
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Issue date:	02/12/2025
From:	Office of Nuclear Reactor Regulation
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IN 2025-01
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ML24323A057

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, DC 20555-0001

February 10, 2025

NRC INFORMATION NOTICE 2025-01:

LESSONS LEARNED WHEN IMPLEMENTING

ASME CODE CASE N-752

ADDRESSEES

All holders of an operating license or construction permit for a nuclear power reactor under

Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Domestic Licensing of

Production and Utilization Facilities, and all holders of a power reactor combined license under

10 CFR Part 52, Licenses, Certifications, and Approvals for Nuclear Plants, that have been

authorized by the U.S. Nuclear Regulatory Commission (NRC) to implement American Society

of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPV Code) Code Case N-

752, Risk-Informed Categorization and Treatment for Repair/Replacement Activities in Class 2 and 3 Systems,Section XI, Division 1, or are considering submittal of a request for NRC

authorization to implement ASME Code Case N-752.

PURPOSE

The NRC is issuing this information notice (IN) to inform licensees and permit holders of

recently observed inconsistencies between the language in licensee programs during the

implementation of Code Case N-752 and the risk-informed methods the NRC approved to be

acceptable to satisfy the requirements of 10 CFR Part 50, Appendix B, Quality Assurance

Criteria for Nuclear Power Plants and Fuel Reprocessing Plants. These inconsistencies could

lead to a misinterpretation that the requirements of 10 CFR Part 50, Appendix B, no longer

apply to safety-related Class 2 and Class 3 structures, systems, and components (SSCs) that

are categorized as low safety significant (LSS) when implementing Code Case N-752. The NRC

expects that recipients will review the information for applicability to their operations and

consider actions, as appropriate, to prevent similar discrepancies. INs may not impose new

requirements, and nothing in this IN should be interpreted to require specific actions and

therefore no written response is required.

DESCRIPTION OF CIRCUMSTANCES

ASME Code Case N-752 describes alternative requirements for repair/replacement activities for

ASME BPV Code Class 2 and 3 items that are categorized as LSS when implementing the code

case, in lieu of certain requirements in the ASME BPV Code,Section XI, Rules for Inservice

Inspection of Nuclear Power Plant Components, Division 1, Rules for Inspection and Testing

of Components of Light-Water Cooled Plants, as incorporated by 10 CFR 50.55a,Codes and

standards. The NRC has not issued a generic acceptance of Code Case N-752 for

implementation at nuclear power plants. Licensees and permit holders may request plant- specific NRC authorization to implement Code Case N-752 in accordance with 10 CFR

50.55a(z), Alternatives to codes and standards requirements. Paragraph (a) in 10 CFR 50.54, Conditions of licenses, specifies conditions for meeting the

quality assurance (QA) criteria in Appendix B of 10 CFR Part 50 for each nuclear power plant

with an operating license issued under 10 CFR Part 50 or with a combined license issued under

10 CFR Part 52.

Licensees are required to comply with NRC regulations, including the QA requirements of 10

CFR Part 50, Appendix B, for safety-related Class 2 and Class 3 LSS items regardless of the

language used in ASME Code Case N-752 or the associated NRC safety evaluations (SEs).

Exemptions from NRC regulations may be granted only in response to specific requests for an

exemption in accordance with 10 CFR 50.12, Specific exemptions. In conjunction with its

authorization of alternatives under 10 CFR 50.55a(z) to implement ASME Code Case N-752, the NRC has not granted any exemptions in accordance with 10 CFR 50.12 regarding the

requirements of 10 CFR Part 50, Appendix B, with respect to design, licensing basis, or

regulatory enforcement. As part of implementing ASME Code Case N-752, a licensee or permit

holder may make changes to its QA program description (QAPD) in accordance with 10 CFR

50.54, Conditions of licenses, while maintaining compliance with 10 CFR Part 50, Appendix B.

10 CFR 50.54(a)(4) requires licensees or permit holders to submit proposed changes to the

QAPD, including all pages affected by that change, and must be accompanied by a forwarding

letter identifying the change, the reason for the change, and the basis for concluding that the

revised QAPD continues to satisfy the criteria of 10 CFR Part 50, Appendix B, and the QA

program description commitments previously accepted by the NRC.

10 CFR 50.54(a)(3) allows licensees to adopt any QA alternative or exception approved by an

NRC SE, provided that the bases of the NRC approval are applicable to the licensee's facility.

10 CFR 50.55a(z) allows licensees to use alternatives to codes and standards requirements

incorporated by reference in 10 CFR 50.55a when authorized by the Director, NRC Office of

Nuclear Reactor Regulation.

NRCs authorization to use ASME Code Case N-752 in accordance with 10 CFR 50.55a(z)

(and/or NRC approval of changes to the QAPD in accordance with 10 CFR 50.54) does not

exempt licensees from complying with the QA requirements of 10 CFR Part 50, Appendix B.

They approve acceptable risk-informed methods to satisfy the QA requirements of 10 CFR Part

50, Appendix B, for safety-related Class 2 and Class 3 LSS items within the scope of Code

Case N-752.

The NRC staff has identified licensees usage of language in revisions to licensee safety

analysis reports, revisions to QAPDs, and other licensee communications that is inconsistent

with the regulatory requirement(s). The following examples provide excerpts of inconsistent

language that the staff has observed in licensee documentation that incorporated Code Case N-

752 (i.e., QAPD LSS component content):

exempt from 10 CFR 50, Appendix B

are not required to comply with the quality assurance requirements of 10 CFR 50,

Appendix B

requirements of 10 CFR 50 Appendix B do not apply

scope of the SSCs exempted from 10 CFR Part 50 Appendix B removal of regulatory requirements

Appendix B QA Program would not apply to the Class 2 and 3 LSS Items under their

Proposed Code Case N-752 Repair/Replacement Program

ASME Code Case N-752 LSS items are also exempt from QA Topical Report (i.e.,

Appendix B requirements)

Usage of the above language (or similar) is inconsistent with the requirement to meet 10 CFR

Part 50, Appendix B, and could result in a violation of the requirement.

DISCUSSION

This IN is intended to inform licensees and permit holders of recently observed inconsistencies

between language used in documents implementing Code Case N-752 (authorized on a plant- specific basis in accordance with 10 CFR 50.55a(z)) and the overarching requirement to meet

10 CFR Part 50, Appendix B.

With respect to ASME Code Case N-752, the NRCs SE for a licensees request to change the

QAPD typically concludes that there is reasonable assurance that the licensees QAPD will

continue to meet the requirements of Appendix B to 10 CFR Part 50 while implementing ASME

Code Case N-752 for the treatment of safety-related Class 2 and Class 3 SSCs identified as

LSS. This conclusion endorses the potential removal of these LSS items from the QAPD when

licensees or permit holders plan to use risk-informed supplemental processes and procedures

that the NRC staff has approved as meeting 10 CFR Part 50, Appendix B, for these LSS items.

Removal of the requirement to meet 10 CFR Part 50, Appendix B, or other licensing-basis

requirements, would need to be requested and considered under 10 CFR 50.12, or 10 CFR

50.90, Application for amendment of license, construction permit, or early site permit, not

under 10 CFR 50.55a or 10 CFR 50.54.

Furthermore, the NRC staff notes that Code Case N-752 includes a footnote that might appear

to exempt Class 2 or Class 3 items categorized as LSS from the QA requirements of ASME

BPV Code,Section XI, paragraph IWA-1400(n). Paragraph IWA-1400(n) references certain

administrative requirements for meeting either 10 CFR Part 50, Appendix B, or ASME NQA-1, Quality Assurance Requirements for Nuclear Facility Applications. This footnote, however, does not provide an exemption from the regulations in 10 CFR Part 50, Appendix B. As noted

above, licensees are required to comply with NRC regulations, including the QA requirements of

10 CFR Part 50, Appendix B, for safety-related Class 2 and Class 3 LSS items unless an

exemption from the 10 CFR Part 50, Appendix B, requirements has been granted in accordance

with 10 CFR 50.12.

The NRCs approval of specific changes to the QAPDs related to the implementation of ASME

Code Case N-752 allows licensees to apply risk-informed supplemental processes and

procedures that the NRC staff has determined to satisfy the requirements in 10 CFR Part 50,

Appendix B, given the low safety significance of individual safety-related Class 2 and Class 3 LSS items within the scope of ASME Code Case N-752. The alternate QA methods only apply

to the LSS function of an item. Licensees and permit holders are encouraged to consider this

information prior to submitting application for, during the application process, and when

implementing ASME Code Case N-752.

CONTACT

S

This IN does not constitute the imposition of a requirement and does not require a specific

written response. Each licensee is responsible for meeting its licensing basis. Please direct any

questions about this matter to the technical contact listed below.

/RA/

Russell Felts, Director

Division of Reactor Oversight

Thomas G. Scarbrough, NRR

301-415-2794 Email: Thomas.Scarbrough@nrc.gov

ML24323A057