ML25008A081

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AUG-MUG 50.69 Presentation 1-2025 (Scarbrough) Final
ML25008A081
Person / Time
Issue date: 01/08/2025
From: Thomas Scarbrough
NRC/NRR/DEX/EMIB
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Download: ML25008A081 (1)
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10 CFR 50.69 Thomas G. Scarbrough Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Air-Operated Valve Users Group Motor-Operated Valve Users Group January 2025

Disclaimer This presentation was prepared by staff of the U.S.

Nuclear Regulatory Commission (NRC). It may present information that does not currently represent an agreed-upon NRC staff position. NRC has neither approved nor disapproved the technical content.

This presentation is based on 10 CFR 50.69 training slides available at ADAMS ML24267A162 public.

AGENDA 3

I.

10 CFR 50.69 Rule II.

10 CFR 50.69 License Amendment Request (LAR)

III.

10 CFR 50.69 Federal Register Notice IV.

10 CFR 50.69 Inspection Procedure V.

10 CFR 50.69 Inspections VI.

Specific 10 CFR 50.69 Technical Topics VII. Conclusion

I. 10 CFR 50.69 Rule 4

10 CFR 50.69 Overview

  • 10 CFR 50.69 allows a licensee or applicant to submit a license amendment request (LAR) to implement risk-informed treatment of structures, systems, and components (SSCs) as an alternative to special treatment requirements (STRs) in NRC regulations.
  • SRM dated October 7, 2004, approved issuance of 10 CFR 50.69 with revision of RISC-3 treatment requirements.
  • 10 CFR 50.69 issued on November 22, 2004, in 69 Federal Register Notice (FRN) 68008 5

Risk-Informed Safety Class Definitions

  • RISC-1 SSCs: safety-related SSCs that perform safety significant functions.
  • RISC-2 SSCs: nonsafety-related SSCs that perform safety significant functions.
  • RISC-3 SSCs: safety-related SSCs that perform low safety significant functions.
  • RISC-4 SSCs: nonsafety-related SSCs that perform low safety significant functions.
  • Safety significant function: function whose degradation or loss could result in a significant adverse effect on defense-in-depth, safety margin, or risk.

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10 CFR 50.69(b), Applicability and Scope of Risk-Informed Treatment of SSCs and Submittal/Approval Process (1) LWR OL holder, Renewed LWR license holder, CP or OL applicant, and 10 CFR Part 52 design approval, COL, and manufacturing license applicant, may voluntarily comply.

(2) Submit LAR under 10 CFR 50.90 containing (i) categorization process description, (ii) systematic process description for plant evaluation, (iii) results of PRA review process, and (iv) evaluations of common cause effects and degradation mechanisms for active and passive functions.

(3) Commission will approve if 10 CFR 50.69(c) met.

(4) Include 50.69(b)(2) information in application.

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RISC-3 and 4 STRs Eliminated by 10 CFR 50.69

  • 10 CFR 50.49 for environmental qualification of electric equipment

RISC-3 and 4 STRs Eliminated by 10 CFR 50.69 (continued)

  • 10 CFR 50.65, except for paragraph (a)(4), regarding maintenance rule
  • Type B and Type C leakage testing requirements in both Options A and B of Appendix J to 10 CFR Part 50, for penetrations and valves with specific criteria.

RISC-3 and 4 STRs Eliminated by 10 CFR 50.69 (continued)

NOTE:

  • Allows alternative treatment instead of compliance with 11 specific special treatment regulations.
  • Must continue to comply with special treatment regulations unless and until alternative treatment is established.

10

Examples of Regulations Not Eliminated by 10 CFR 50.69 11

  • ASME BPV Code Section III requirements in 10 CFR 50.55a, but repair/replacement activities might impact requirements.

10 CFR 50.69(c), SSC Categorization Process (1) SSCs must be categorized using a process that determines if an SSC performs one or more safety significant functions and identifies those functions and must (i) consider plant-specific PRA, (ii) determine SSC functional importance, (iii) maintain defense in depth, (iv) provide reasonable confidence for RISC-3 SSCs, and (v) be performed for entire systems and structures, not for selected components within a system or structure.

(2) SSCs must be categorized by Integrated Decision-Making Panel (IDP).

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10 CFR 50.69(d)(1)

RISC-1 and 2 SSC Treatment Requirements The licensee or applicant shall ensure that RISC-1 and RISC-2 SSCs perform their functions consistent with the categorization process assumptions by evaluating treatment being applied to these SSCs to ensure that it supports the key assumptions in the categorization process that relate to their assumed performance.

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10 CFR 50.69(d)(2)

RISC-3 SSC Treatment Requirements The licensee or applicant shall ensure, with reasonable confidence, that RISC-3 SSCs remain capable of performing their safety-related functions under design-basis conditions, including seismic conditions and environmental conditions and effects throughout their service life. The treatment of RISC-3 SSCs must be consistent with the categorization process. Inspection and testing, and corrective action shall be provided for RISC-3 SSCs.

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10 CFR 50.69(d)(2)(i) and (ii)

(i) Inspection and testing. Periodic inspection and testing activities must be conducted to determine that RISC-3 SSCs will remain capable of performing their safety-related functions under design-basis conditions; and (ii) Corrective action. Conditions that would prevent a RISC-3 SSC from performing its safety-related functions under design-basis conditions must be corrected in a timely manner. For significant conditions adverse to quality, measures must be taken to provide reasonable confidence that the cause of condition is determined and corrective action taken to preclude repetition.

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10 CFR 50.69(e), Feedback and Process Adjustment (1) RISC-1, 2, 3 and 4 SSCs. Review plant changes, operational experience, and update categorization and treatment every 2 RFOs.

(2) RISC-1 and 2 SSCs. Monitor performance and make adjustments as necessary.

(3) RISC-3 SSCs. Consider data collected in 50.69(2)(i) to determine any adverse performance and make adjustments as necessary.

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10 CFR 50.69(f), Program Documentation, Change Control and Records (1) Document the basis for SSC categorization.

(2) Update FSAR to reflect systems categorized.

(3) When first implementing, FSAR changes do not need 10 CFR 50.59 evaluation. Thereafter, FSAR changes may be made if 10 CFR 50.69 and 50.59 continue to be met.

(4) When first implementing, QA Plan changes do not need 10 CFR 50.54(a) evaluation. Thereafter, QA Plan changes may be made if 10 CFR 50.69 and 50.54(a) continue to be met.

17

10 CFR 50.69(g), Reporting Submit LER under 10 CFR 50.73(b) for any event or condition that prevented, or would have prevented, a RISC-1 or RISC-2 SSC from performing a safety significant function.

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II. 10 CFR 50.69 License Amendment Request 19

10 CFR 50.69 LAR Review

  • NRC staff review of an LAR to implement 10 CFR 50.69 focuses on the risk categorization process.
  • During the LAR review, NRC staff do not review treatment planned by the licensee or applicant to satisfy 10 CFR 50.69(d).
  • Licensees should discuss Technical Specifications in 50.69 LAR.
  • NRC staff has approved 50.69 implementation for many nuclear power plants.

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III. 10 CFR 50.69 Federal Register Notice 21

10 CFR 50.69 Commission Guidance

  • 69 FRN 68008, dated Nov. 22, 2004, discusses the Commission positions on 10 CFR 50.69 and its implementation.
  • NRC inspectors should review FRN for Commission guidance.
  • FRN states that STRs are prescriptive requirements as to how licensees are to treat SSCs.
  • The following slides include highlights of the Commission guidance on specific aspects of 10 CFR 50.69.

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FRN: Special Treatment Requirements

  • Prescriptive requirements as to how licensees are to treat SSCs (e.g., safety-related) are referred to as STRs.
  • STRs developed to provide greater assurance that SSCs will perform their functions under particular conditions with high quality and reliability.
  • STRs include particular examination techniques, testing strategies, documentation requirements, personnel qualification requirements, and independent oversight.
  • Distinction between treatment and special treatment is degree of NRC specification as to what must be implemented for particular SSCs or conditions.

23

FRN: RISC-1 and 2 Treatment

  • For RISC-1 and 2 SSCs, 10 CFR 50.69 maintains current regulatory requirements as adequate for design-basis performance.
  • 50.69(d)(1) requires sufficient treatment be applied to support credit taken for SSCs for beyond design basis events.
  • In some cases, licensees might need to enhance RISC-1 and 2 SSC treatment to support credit in categorization process to reflect actual treatment practices or document performance capability.
  • 10 CFR 50.69(e) requires monitoring and adjustment as needed based on experience.

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FRN: RISC-3 Treatment

  • 10 CFR 50.69(d)(2) imposes requirements that are intended to maintain RISC-3 SSC design-basis capability.
  • Although individually RISC-3 SSCs are not significant to plant safety, they perform functions necessary for certain design-basis events.
  • Collectively, RISC-3 SSCs can be safety significant, and it is important to maintain their design-basis functional capability.
  • Maintenance of RISC-3 design-basis functionality is important to ensure defense-in-depth and safety margins are maintained.
  • Commission is allowing greater flexibility and lower level of assurance for RISC-3 SSCs.

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FRN: RISC-3 Treatment (continued)

  • Licensees need to obtain data or information sufficient to make technical judgement that RISC-3 SSCs remain capable of performing safety-related functions under design-basis conditions, and to enable licensees to take actions to restore equipment performance consistent with corrective action requirements.
  • 10 CFR 50.69 rulemaking is only risk-informing the scope of STRs.
  • Process and requirements established in 50.69 do not extend to making changes to design-basis functional requirements of SSCs.

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FRN: 50.69(d)(2) RISC-3 Treatment Guidance

  • Although 50.49 environmental qualification requirements are removed, 10 CFR Part 50, Appendix A, requirement that electric equipment important to safety be capable of performing intended functions under environmental conditions is not eliminated.
  • RISC-3 SSCs continue to be required to function under design-basis seismic conditions, but not required to be qualified by testing or specific engineering methods in accordance with 10 CFR Part 100.
  • Rule allows licensee to select technically defensible method to show RISC-3 SSCs will remain functional when subject to design earthquake loads.

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FRN: 50.69(d)(2) RISC-3 Treatment Guidance (continued)

  • Licensee must take into account assumptions in the categorization process regarding design-basis capability and reliability of RISC-3 SSCs to perform safety-related functions throughout service life.
  • Licensee responsible for addressing vendor recommendations and operational experience.

FRN: 50.69(d)(2)(i) Inspection-Testing Guidance

  • Licensee must implement periodic testing or inspection sufficient to provide reasonable confidence that pumps and valves will be capable of performing safety-related functions under design-basis conditions.
  • Licensee will need to obtain sufficient operational information or performance data to provide reasonable confidence that RISC-3 pumps and valves will be capable of performing safety-related functions if called upon to function under operational or design-basis conditions over the interval between periodic testing or inspections.
  • Exercising a valve or pump does not provide reasonable confidence of design-basis capability.

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FRN: 50.69(d)(2)(ii) Correction Action Guidance

  • Conditions that would prevent a RISC-3 SSC from performing safety-related functions under design-basis conditions must be corrected in timely manner.
  • In case of significant conditions adverse to quality, the rule requires measures be taken to provide reasonable confidence that the cause of the condition is determined and corrective action taken to preclude repetition.
  • Effective implementation of corrective action process would include timely response to information from plant SSCs, overall plant operations, and industry generic activities that might reveal performance concerns for RISC-3 SSCs on both individual and common-cause basis.

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FRN: 50.69(e) Feedback and Process Adjustment

  • Date that NRC grants 50.69 license amendment begins updating interval.
  • If significant adverse impact, licensee must update categorization or treatment without waiting for 2 RFO schedule.
  • Information might be from SSC performance, vendor recommendations, and operational experience including NRC information notices or generic letters.
  • Might need to move RISC-3 SSCs into RISC-1.
  • Monitor all unavailabilities and functional failures.
  • Monitor credit for beyond design basis functions.
  • Consider 50.69(d)(2)(i) data and make categorization or treatment adjustments for RISC-3 SSCs.

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FRN: 50.69(f) Program Documentation

  • Administrative requirements for keeping information current, handling planned changes to programs and processes, and records.
  • Documentation must address why component was determined to be safety significant or low safety significant.
  • Maintain clear information on minimum level of detail about requirements.
  • No evaluation under 10 CFR 50.54 and 50.59 for initial implementation, but evaluation for future changes.
  • Categorization change control process through LAR license condition.
  • Records maintained until Commission terminates facility license.

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FRN: 50.69(g) Reporting

  • Provides new reporting requirement applicable to events or conditions that prevented, or would have prevented, a RISC-1 or 2 SSC from performing a safety significant function.
  • Possible for events and conditions to arise that impact whether RISC-1 and 2 SSCs would perform beyond design basis functions consistent with categorization process assumptions.

33

FRN: RISC-4 Treatment Guidance

  • Justified in view of low safety significance.
  • Overall, any changes beyond STRs must be made per existing design change control requirements, including 50.59, as applicable.

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FRN: 50.69 Implementation Inspection

  • IP will incorporate inspection guidance for monitoring 50.69 implementation.
  • Sample inspections of plants implementing 50.69
  • Inspections will focus on implementation of categorization process.
  • Inspections will also evaluate treatment under 50.69 with primary attention to programmatic and common-cause issues, including those associated with known degradation mechanisms.
  • Inspections might provide operating experience information on RISC-3 SSCs for other licensees.

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Post-FRN Guidance 36

  • RG 1.201 states STRs removed for RISC-3 SSCs and replaced with high-level requirements intended to provide sufficient regulatory treatment, such that SSCs are still expected to perform safety-related functions under design-basis conditions, albeit at a reduced level of assurance compared to current STRs.

IV. 10 CFR 50.69 Inspection Procedure 37

Inspection Procedure IP 37060 38 IP 37060 (October 2022, ML22075A287), 10 CFR 50.69 Risk-Informed Categorization and Treatment of Structures, Systems, and Components Inspection, provides guidance for inspection of licensee programs to implement 10 CFR 50.69:

- Verify licensee programs and procedures incorporate license amendment.

- Verify licensee properly implements categorization process.

- Verify that licensee properly implements alternate treatment requirements.

IP 37060 Inspection Requirements 39

  • Review of Licensees Programs and Procedures:

- Categorization process

- RISC-1 and RISC-2 SSC treatment

- RISC-3 alternate treatment

- Feedback and process adjustments

- Program documentation, change control, and records Review of Licensees 10 CFR 50.69 Program Implementation Confirm proper categorization Implementation for entire systems RISC-1 and 2 SSC credit in PRA RISC-3 alternate treatment Reporting

IP 37060 Inspection Requirements (continued) 40 Problem Identification and Resolution Verify RISC-3 SSC failures corrected and common cause reviewed Review licensee past audits and self-assessments Review corrective actions in accordance with IP 71152 Review of Licensees Feedback and Process Adjustments

- Update categorization or treatment processes in a timely manner

- Monitor RISC-1 and 2 SSC performance and feedback

- Evaluate RISC-3 SSC data and adjustments

RISC-3 Inspection Guidance 41

  • Confirm RISC-3 SSC treatment provides reasonable confidence of performing safety-related functions.
  • Select 1 to 3 RISC-3 SSCs to verify alternate treatment program.
  • Ensure inspection, testing and corrective action reasonable because collectively RISC-3 SSCs can be safety significant.
  • Ensure extent of conditions review where treatment found deficient.
  • Industrial practices might not be sufficient alone for adequate technical basis of design-basis capability.
  • General Design Criteria in Appendix A to Part 50 continue to apply.
  • Latest IP revision provides guidance for GDC-4 environmental qualification (including aging and synergistic effects).

RISC-3 SSC Examples 42

  • RISC-3 SSCs will comprise most of the safety-related SSCs at a 50.69 plant.
  • One system may include RISC-1, 2, 3 and 4 components.
  • Typical RISC-3 component examples include:

o Residual heat removal system piping, pumps, and valves o Containment spray system piping, pumps, and valves o Service water system piping, pumps, and valves

V. 10 CFR 50.69 Inspections 43

10 CFR 50.69 Inspections Vogtle Units 1 and 2 Inspection Report (IR) 05000424 and 425/2016008, dated August 10, 2016 (ML16223A738): June 13 to 30, 2016 Limerick Units 1 and 2 IR 05000352 and 353/20200010, dated March 11, 2020 (ML20073H282): February 10 to 27, 2020 Calvert Cliffs Units 1 and 2 IR 05000317 and 318/2023011, dated May 10, 2023 (ML23130A003): April 10-27, 2023 Peach Bottom Units 2 and 3 IR 05000277 and 278/2023013 (ML23069A019): January 23 to February 10, 2023 44

10 CFR 50.69 Inspections (continued)

Vogtle Units 1 and 2 PI&R IR 05000424 and 425/2023011, dated August 11, 2023 (ML23222A008): June 12 to 30, 2023 Farley Units 1 and 2 IR 05000348 and 364/2024010 (ML24101A203): January 22 to February 9, 2024 Hatch Units 1 and 2 IR 05000321 and 366/2024010 (ML24310A171): September 9 to 25, 2024 45

VI. Specific 10 CFR 50.69 Technical Topics 46

RISC-1 and 2 Treatment

  • RISC-1 and 2 SSCs need to perform their functions consistent with categorization process assumptions based on applied treatment to ensure that key assumptions in the categorization process are supported.
  • In some cases, licensees might need to enhance RISC-1 and 2 SSC treatment to support credit taken in categorization process to reflect actual treatment practices and/or document performance capability.
  • 50.69(e) requires monitoring and adjustment as needed based on experience in implementing 10 CFR 50.69.

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RISC-3 MOV Treatment

  • Licensee must satisfy 10 CFR 50.69(d)(2) for RISC-3 MOVs, including inspection and testing, and corrective action.
  • In 69 FR 68008, Commission provides guidance for inspection and testing, and corrective action, for RISC-3 MOVs to demonstrate reasonable confidence in their capability to perform safety functions.

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RISC-3 Piping Replacement

  • Commission specifies RISC-3 SSCs required to be capable of withstanding design input earthquake loads and required load combinations for RISC-3 SSC design, but seismic qualification under 10 CFR Part 100 is not required.
  • Commission states licensee must have technically defensible method for demonstrating replacement piping can withstand design seismic loads.
  • Regarding ASTM versus ASME piping, adequate pedigree needs to be demonstrated (such as B31.1 piping).
  • Fracture toughness requirements need to be satisfied if included in original design specification.

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ANO Passive Component Classification Method

  • In SE dated 4-22-2009, NRC authorized use of risk-informed safety classification and treatment program for repair/replacement activities in Class 2 and 3 systems at ANO-2 (ML090930246).
  • LSS components are exempt from ASME BPV Code for repair/replacement activities, but owner-defined activities confirm with reasonable confidence that LSS item will perform safety functions under design-basis conditions.
  • Treatment will include design controls, procurement, installation, inspection, and configuration control.
  • Entergy stated that original construction code fracture toughness requirements will be met.

50

Systems in Categorization Process

  • 10 CFR 50.69(c)(v) states the categorization process must: Be performed for entire systems and structures, not for selected components within a system or structure.
  • FRN on 68019 states that this scope ensures that all safety functions associated with a system or structure are properly identified and evaluated, and that the entire set of components that comprise a system or structure are considered and addressed.
  • All functions for a given component need to be appropriately considered, if not the component should remain uncategorized
  • Bases for system boundaries may be equipment tag designators or other means as documented by the licensee.

51

Operational Leakage for 10 CFR 50.69 Plants

  • For RISC-3 and 4 SSCs that are ASME BPV Code Class 2 or 3, ISI and repair/replacement requirements (except fracture toughness) in 50.55a do not apply when implementing 10 CFR 50.69.

10 CFR 50.69 Welder and Inspector Capability

  • RISC-1 and 2 SSC requirements for welder and inspector qualification remain applicable under 10 CFR 50.69.
  • For RISC-3 SSCs that are ASME BPV Code Class 2 and 3, ISI and repair and replacement requirements (except fracture toughness) in 10 CFR 50.55a do not apply.
  • FRN does not address RISC-3 SSC welder or inspector capability, but refers to a technically defensible method in discussing various aspects of RISC-3 SSC capability.

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Reportability for 10 CFR 50.69 Plants

  • STR reporting requirements continue to apply for RISC-1 and 2 SSCs, but reporting requirements for RISC-3 and 4 SSCs are removed.
  • In addition, 10 CFR 50.69(g) requires licensees to submit a licensee event report for any event or condition that would have prevented RISC-1 or RISC-2 SSCs from performing a safety significant function.
  • FRN states it is possible for events and conditions to arise that impact whether RISC-1 or RISC-2 SSCs would perform beyond design basis functions consistent with the performance capability credited in the categorization process. This reporting requirement is intended to capture these situations.

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Technical Specifications versus 10 CFR 50.69

  • 10 CFR 50.55a requirements for Inservice Testing of RISC-3 and 4 components are removed by 10 CFR 50.69 with separate requirements for testing and inspection of RISC-3 components.
  • Some TS refer to Inservice Testing Program for Surveillance Requirements (SRs) for component testing.

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VII. Conclusion

  • 10 CFR 50.69 allows flexibility for licensees in applying treatment to plant SSCs based on their safety significance determined by the 50.69 categorization process.
  • 10 CFR 50.69 requires that SSCs with low safety significance be capable of performing their safety functions but with less confidence than when applying STRs.

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Questions?

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