ML21349A930
| ML21349A930 | |
| Person / Time | |
|---|---|
| Issue date: | 12/15/2021 |
| From: | Daniel Merzke NRC/NRR/DRO/IRIB |
| To: | |
| Daniel Merzke NRR/DRO/IRAB, 4251457 | |
| Shared Package | |
| ML21349A925 | List: |
| References | |
| Download: ML21349A930 (21) | |
Text
Graded Approach to Inspection Dan Merzke U.S. Nuclear Regulatory Commission
Inspection - Operating Reactors
- Creating a baseline inspection program
- Minimum inspection for all reactor licensees
- What to inspect, how much to inspect, how often to inspect
- Requirements and guidance documented in inspection procedures
- Resource requirements depend on:
- Amount of inspection to assure adequate protection
- Number of operating units 2
Inspection - Operating Reactors
- Step 1- Identify licensee activities and structures, systems, and components (SSCs) that are important to safety.
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Inspection - Operating Reactors
- Step 2 - Determine which factors are applicable to the decision
- Type of facility (PWRs have different ISI requirements)
- Stage in life cycle (construction and decommissioning inspection requirements differ from operational inspections)
- Operating experience - focus inspections on areas where safety-significant SSCs have a higher failure probability
- Inspector experience 4
Inspection - Operating Reactors
- Step 3 - Integrate the applicable factors into the determining the optimal resource effort required to ensure licensees are operating their facilities in a manner that protects public health and safety, and the environment. Regulator determines the appropriate inspection sample size and frequency.
- What to inspect, how much to inspect, how often to inspect 5
Inspection - Operating Reactors 6
Inspection - What to Inspect
- Process described in SECY-99-007
- What to inspect
- Each cornerstone has several attributes from which the inspectable areas are derived.
- Inspectable areas were selected based on their risk significance 7
Inspection - What to Inspect
- Risk Information Matrices (RIMs) developed in determining which activities, systems, or components are to be inspected in the baseline inspection program.
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Inspection - RIM 10
Inspection - Operating Reactors
- How much to inspect / how often to inspect
- Sample size and number of hours were developed based on expert judgment and relevant risk information on how much inspection activities would be sufficient to ensure verification that the licensee was meeting the objectives of all seven cornerstones.
- IMC 0308, Attachment 2, Technical Basis for Inspection Program, documents scope and basis for each inspectable area.
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Inspection - Operating Reactors
- What to inspect
- Inspection procedures provide guidance to inspectors on sample selection, focusing on highest risk SSCs or activities 12
Inspection - Operating Reactors
- Sample sizes / Frequency
- Inspection procedures describe required sample sizes for completion, and frequency of inspection Minimum Baseline Completion Sample Sample Requirements Budgeted Range Requirements Sample Type Section(s) Frequency Sample Size Samples Hours Partial Walkdown* 03.01 Annual 12 per site 12-16 80 +/- 12 per site Complete Walkdown** 03.02 Annual 2 per site 2 Each partial walkdown sample is budgeted at 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
- Perform one complete walkdown sample approximately every 6 months. Each complete walkdown sample is budgeted at 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
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Inspection - Feedback Loop
- Inspection program should have a feedback loop to regularly adjust sample sizes, resource estimates, and what to inspect
- Operating experience (what to inspect)
- Biennial ROP realignment - realign sample sizes and resources
- Feedback from inspectors 14
Inspection - Resources
- Resource requirements for 2-Unit PWR (annual hours) 2000 2019 Class 1 RTR 71111 (Reactor Safety) 1547 1286 49 Procedures 71114 (EP) Procedures 72 88 12 71124 (Radiation Protection) 172 142 18 Procedures 71130 (Security) Procedures 96 278 Other Procedures (71151, 52, 53) 278 505 Plant Status 700 699 Total Hours 2865 2998 15
Inspection Based on Performance
- Graded approach to inspection based on performance
- As licensee performance declines, inspection increases
- Described by Action Matrix 16
Action Matrix Concept Licensee Regulatory Degraded Multiple/Repetitive Unacceptable Response Response Performance Degraded Performance Cornerstone Column 1 Column 2 Column 3 Column 4 Column 5
- Increasing safety significance
- Increasing NRC inspection efforts
- Increasing NRC/licensee management involvement
- Increasing regulatory actions 17
Inspection Based on Performance
- Step 1 - Identify activities and SSCs important to safety
- Focus on activity or SSC where performance is deficient
- Step 2 - Determine which factors applicable
- Safety significance of deficiency
- Isolated vs site-wide (extent of condition)
- Step 3 - Integrate factors to determine optimal resources
- Scope of inspection effort described in supplemental inspection procedures based on number and/or safety significance of performance deficiencies and performance indicators18
Inspection Based on Performance
- Supplemental Inspections
- Column 2 - IP 95001 supplemental inspection (40-120 hours)
- Column 3 - IP 95002 supplemental inspection (200 hours0.00231 days <br />0.0556 hours <br />3.306878e-4 weeks <br />7.61e-5 months <br />)
- Column 4 - IP 95003 supplemental inspection (3000 hours0.0347 days <br />0.833 hours <br />0.00496 weeks <br />0.00114 months <br />) -
diagnostic site-wide inspection
- Objectives and requirements described in each procedure
- All inspection objectives must be satisfactorily met for licensee move back to Column 1 19
References
- IMC 0305, Operating Reactor Assessment Program
- IMC 0308, Attachment 2, Technical Basis for Inspection Program
- IMC 2515, Light-Water Reactor Inspection Program
- Inspection Procedure 95001, Supplemental Inspection Response to Action Matrix Column 2 Inputs
- Inspection Procedure 95002, Supplemental Inspection for One Degraded Cornerstone or Any Three White Inputs in a Strategic Performance Area
- Inspection Procedure 95003, Supplemental Inspection for Repetitive Degraded Cornerstones, Multiple Degraded Cornerstones, Multiple Yellow Inputs or One Red Input 20
Action Matrix 21