ML22168A161
| ML22168A161 | |
| Person / Time | |
|---|---|
| Issue date: | 06/23/2022 |
| From: | Paul Prescott NRC/NRR/DRO/IQVB |
| To: | |
| Prescott, P 301-415-3026 | |
| Shared Package | |
| ML22168A146 | List: |
| References | |
| Download: ML22168A161 (23) | |
Text
Risk-Informed Safety Class (RISC)-3 Treatment of Structures, Systems and Components (SSCs)for Nuclear Power Reactors.
Paul Prescott Office of Nuclear Reactor Regulation Division of Reactor Oversight Quality Assurance and Vendor Inspection Branch (IQVB)
10 CFR 50.69 RULE Risk-Informed Safety Class 2
10 CFR 50.69 RULE Categorization Process 3
Categorize SSCs as RISC-1, -2, -3 or -4
- 1. Consider Plant-Specific PRA
- 2. Determine Functional Importance
- 3. Maintain Defense-in-Depth
- 4. Maintain Safety Margin/ Small Risk Increase
- 5. Categorize Entire Systems NEI 00 ML052900163 RG 1.201 - ML061090627
10 CFR 50.69 RULE Program Documentation 4
Basis for Removing Special Treatment Requirement UFSAR Update Quality Assurance Plan Update
10 CFR 50.69 RULE Special Treatment Requirements 5
Special Treatment Requirements Regulations specific requirements QA Requirements Inspection Testing Condition Monitoring Other Elements
10 CFR 50.69 RULE Special Treatment Requirements 6
Specific Special Treatment Requirements For RISC-3 and RISC-4 Retain Special Treatment Requirements For RISC-1 and RISC-2
10 CFR 50.69 RULE Alternative Requirements 7
Alternative Treatment Requirements For RISC-3 and RISC-4 List of Regulations in 50.69(b)(1)
10 CFR 50.69 RULE RISC-3 Alternative Treatments 8
- 1. Inspection/Testing:
Remain Capable of Performing Safety Related Function
- 2. Corrective Action:
Cause Identified and Action Taken to Prevent Repetition Reasonable Confidence:
10 CFR 50.69 RULE RISC-3 Alternative Treatments 9
Criteria for Reasonable Assurance Special Treatments in The Regulations Criteria for Reasonable Confidence NUREG/CR-6752: ML020330051 Combination of:
Commercial Requirements Engineering Specs Processes/Procedures QA Programs
10 CFR 50.69 RULE RISC-3 Alternative Treatments 10 An example of alternative treatment being implemented:
An ASME Code Case for replacement activities in Class 2/3 systems allows for exemption of items from meeting repair/replacement requirements for low safety significant items
10 CFR 50.69 RULE RISC-3 Alternative Treatments 11 In this example, an alternative treatment proposed may be the use of an alternate standard, such as B31.1, Power Piping, being implemented.
10 CFR 50.69 RULE Reporting Requirements 12 New RISC-1/-2 Reporting Requirements under 50.73 for Beyond Design Basis Events Reporting Under 10 CFR Part 21, 50.55(e), and 50.72, 50.73 For RISC-1 SSCs (existing requirements)
Reporting Under 50.72 and 50.73 For RISC-2 SSCs (existing requirements)
RISC-3 and RISC-4 SSCs Excluded From Reporting Requirements
10 CFR 50.69 INSPECTION PROCEDURES IP-37060 vs Baseline Inspections 13 Adoption/
Event RISC-3 Performance-Based Elements IP-37060 Inspection ROP Baseline Inspections
10 CFR 50.69 INSPECTION PROCEDURES IP-37060 Implementation Inspection 14 Program Focused Adoption/Event Not Ongoing Baseline IP-37060
10 CFR 50.69 INSPECTION PROCEDURES IP-37060 Implementation Inspection The inspection will focus on two questions:
- 1. Did the site follow the requirements outlined in the license amendment and associated license conditions?
- Changes used PRA insights
- Boundaries correct
- Changes were based upon as-built and maintained plant
- 2. Are alternative treatment requirements implemented?
- System testing and maintenance performed as scheduled?
- Are the changes being monitored to assess effectiveness?
- Do the alternative treatment requirements provide reasonable confidence RISC-3 SSCs will perform their safety-related functions?
15
10 CFR 50.69 INSPECTION PROCEDURES IP-37060 Implementation Inspection Verification of Program Aspects:
- Verify the licensee has implemented the license amendment in accordance with the associated safety evaluation:
- License conditions were implemented
- Site procedures reflect approved categorization process
- Sensitivity studies ensured proper categorization of RISC-3 components 16
10 CFR 50.69 INSPECTION PROCEDURES IP-37060 Implementation Inspection Verification of Program Aspects:
- Verify programs in place for RISC-3 components:
17 Corrective Actions Inspection
& Testing
18 10 CFR 50.69 INSPECTION PROCEDURES IP-37060 Implementation Inspection Review of licensee programs and procedures:
Categorization Process SSC Importance Entire System Categorized Safety Margins Defense-in-Depth Integrated Decision-making panel
19 10 CFR 50.69 INSPECTION PROCEDURES IP-37060 Implementation Inspection RISC-3 Inspection Items:
Reasonable Confidence Inspection Testing Corrective Action Extent of Condition Part 50 Appendix A Degradation of Multiple RISC-3 SSCs
20 10 CFR 50.69 INSPECTION PROCEDURES IP-37060 Implementation Inspection Resource Documents:
NEI 00 (ADAMS Accession No. ML052900163)
RG 1.201 - (ADAMS Accession No. ML052900163)
ASME OM Code, Part 49 NUREG/CR-6752 - (ADAMS Accession No. ML020330051)
21 10 CFR 50.69 INSPECTION PROCEDURES IP-37060 Implementation Inspection Points to Emphasize:
RISC-3 Alternative Treatment Justifications Reasonable confidence to perform safety function May need to retain some code/inspection requirements
10 CFR 50.69 Baseline Inspection Procedures 22 Inspection/Testing Corrective Action Feedback/Process Adjustment Baseline Inspections (RISC-3)
10 CFR 50.69 Baseline Inspection Procedures 23 IP 71111.12 Maintenance Effectiveness IP 71111.18 Plant Modifications IP 71111.22 Surveillance Testing IP 7153 Followup of Events and Notices of Enforcement Discretion