ML21167A127
| ML21167A127 | |
| Person / Time | |
|---|---|
| Issue date: | 06/16/2021 |
| From: | Matthew Humberstone NRC/RES/DRA |
| To: | |
| Vasavada S | |
| Shared Package | |
| ML21167A163 | List: |
| References | |
| Download: ML21167A127 (16) | |
Text
LICENSING MODERNIZATION PROJECT FOR OPERATING REACTORS Matt Humberstone June 2021
2 1
Feasibility Overview Results Scope Path Forward Proposals Discussion Discussion Discussion Regulatory Support PHASE PHASE PURPOSE FFR Scope
- Feasibility
- Limited Scope
- Level 3 PRA - Internal Events Phase 1
- Expanded Insights
- More Event Sequences
- Level 3 PRA - External Events Phase 2 FFR SCOPE
3 2
4 5
1 OBJECTIVES: LMP for Operating Reactors Limited Resource project to support future NRC needs jumped over the lazy dog. LMP Feasibility Pilot LMP methodology Use L3PRA results Risk-Insights on LWRs Communicate Yes, the LMP methodology is feasible for LWRs Used the LMP methodology with the L3PRA model results Identified LMP challenges (Centerline dose, crediting evacuations, accident family limitations, etc.)
LWR safety profile in-line with NLWR target Shared Progress/Results Identify Issues/Challenges RMT briefing ACRS briefing PWROG RIC digital exhibit OEDO Final Report PSA paper Two-pager
Non-LWR licensing LWR Experience Risk-Informed and Performance-Based Severe Accident Research Communication: Slide 2 LMP Methodology NRC Level 3 PRA Model 1.E-08 1.E-07 1.E-06 1.E-05 1.E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 Event Sequence Frequency TEDE at EAB (rem)
LMP Frequency - Consequence Curve NEI 18-04 Technical Approach
6 Level 3 PRA (L3PRA) Process Cutsets ~50,000 Plant Damage States (PDS) -368 Release Categories -16
01 03 MELCOR Accident Consequence Code System (MACCS) 02 06 Severe Accidents at Nuclear Power Plants Consequence Analysist 04 Source Term and Radionuclide release Transport and Dispersion 05 Dosimetry and Health Effects Risk and Uncertainty
16 Release Categories Communication: Slide 5 B
Release Categories 5
Largest Dose Categories (orange) 6 Middle Dose Categories (gray) 5 Lowest Dose Categories (blue)
9 Release Category Contributions Dose Contributions Frequency Contributions Largest Dose Middle Dose Low Dose
10 Basic LMP Frequency-Consequence Curve 1.E-08 1.E-07 1.E-06 1.E-05 1.E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 Event Sequence Frequency TEDE(rem) at the Exclusion Area Boundary ANTICIPATED OPERATIONAL OCCURANCE (AOO) REGION 10 CFR 50.34 Dose Limit EPA PAG Dose Limit Individual Risk QHO (Prompt)
DESIGN BASIS EVENT (DBE)
REGION BEYOND DESIGN BASIS EVENT (BDBE) REGION Increasing Risk Significance Decreasing Risk Significance 10 CFR 20 Iso-Risk Line Design Objective Selection of Licensing Basis Events (LBEs)
Safety Classification of Structures, Systems, and Components (SSCs)
Determination of Defense-in-depth (DID) Adequacy
11 LMP Frequency - Consequence Comparison Lowest Dose Middle Dose Largest Dose
Opportunities
- NLWR Licensing
- Risk-Informing CH 15 Accident Analysis
- Licensing
- Oversight Operating Reactor Safety Insights LMP Methodology can be used beyond the original intent Insights for NLWR licensing PHASE 1 CONCLUSIONS Reports/Papers Final Report PSA paper Two pager Communication RMT briefing ACRS briefing PWROG briefing OEDO RIC digital exhibit NWLR Licensing Insight Understand LMP upfront 30-day TEDE, EAB, etc.
LMP Challenges Is TEDE the centerline maximum dose? (averaged???)
Is evacuation ignored?
Limitations on accident families?
Operating Reactors In-line with NLWR guidance Consistent with historical perspective
ACCIDENT SEQUENCES EXPANDED INSIGHTS Communication: Slide 5 A
B Sequence Review Deeper Understanding Uncertainty L3PRA External Events FLEX PHASE 2
14 Now
- Rely on deterministic approaches
- May not explicitly rely on risk-insights
- Develop tools to better focus on risk-significant aspects PROPOSALS
- Risk-Inform CH 15 analysis
- 2 Approaches
- NLWR Licensing Support Risk-Informed Regulator RES SUPPORT (LMP use in regulatory framework)
- Rely on risk-insights
- More efficient reviews
- Focus on risk-significant accidents
- Use LMP F-C chart
- Categorize accidents
- Distance from the F-C target Approach 1
- Map consequences to Level 1/LERF risk metrics
- Find Correlations
- Use Level 1/LERF risk metrics to categorize Approach 2 CH 15 Accident Analysis Research Options
B A
C Program Office Engagement PHASE 2 of the LMP for Operating Reactors Continue Communication Effort Briefings Conferences NEXT STEPS/QUESTIONS