ML21167A127

2 - Lmp for Operating Reactors

ML21167A127
Person / Time
Issue date:	06/16/2021
From:	Matthew Humberstone NRC/RES/DRA
To:
Vasavada S
Shared Package
ML21167A163	List: ML21167A104 ML21167A127 ML21167A137 ML21167A142 ML21167A154 ML21167A161
References
Download: ML21167A127 (16)

Text

LICENSING MODERNIZATION PROJECT FOR OPERATING REACTORS Matt Humberstone June 2021

PURPOSE 1PHASE FFR Scope 2

PHASE Regulatory Support Discussion Discussion Discussion Feasibility Scope Overview Path Proposals Forward Results

FFR SCOPE

• Feasibility

• Limited Scope Phase 1

• Level 3 PRA - Internal Events

• Expanded Insights

• More Event Sequences

• Level 3 PRA - External Phase 2 Events

OBJECTIVES: LMP for Operating Reactors 1 Limited Resource 2 4 project to support 3

future NRC needs 5 jumped over the lazy Yes, the LMP methodology is feasible for LWRs dog. LMP Feasibility Used the LMP methodology with the L3PRA Pilot LMP methodology model results Identified LMP challenges (Centerline Identify Issues/Challenges dose, crediting evacuations, accident family limitations, etc.)

Use L3PRA results LWR safety profile in-line with NLWR target Risk-Insights on LWRs Shared Progress/Results

• RMT briefing

• OEDO Communicate

• ACRS briefing

• Final Report

• PWROG

• PSA paper

• RIC digital exhibit

• Two-pager

Communication: Slide 2 Technical Approach Risk-Informed and Severe Accident Research Performance-Based LWR Experience Non-LWR licensing LMP Frequency - Consequence Curve Event Sequence Frequency 1.E+01 1.E+00 1.E-01 1.E-02 NRC Level 3 1.E-03 NEI 18-04 LMP PRA Model 1.E-04 Methodology 1.E-05 1.E-06 1.E-07 1.E-08 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 TEDE at EAB (rem)

Level 3 PRA (L3PRA) Process Plant Damage Release Cutsets ~50,000 States (PDS) -368 Categories -16 6

Severe Accidents at Nuclear Power Plants Risk and 01 Consequence Uncertainty Analysist 06 MELCOR 02 Accident Consequence Code System (MACCS) 05 03 Source Term Dosimetry and and Health Effects Radionuclide 04 release Transport and Dispersion

Communication: Slide 5 Release Categories 5 Largest Dose Categories (orange) 6 16 Release Middle Dose B Categories Categories (gray) 5 Lowest Dose Categories (blue)

Release Category Contributions Dose Contributions Frequency Contributions Largest Dose Middle Dose Low Dose 9

Basic LMP Frequency-Consequence Curve 1.E+01 Increasing Risk Event Sequence Frequency 1.E+00 10 CFR 20 Selection of Licensing Significance Iso-Risk Line ANTICIPATED Basis Events (LBEs) 1.E-01 OPERATIONAL OCCURANCE 10 CFR 50.34 Dose Limit (AOO) REGION 1.E-02 DESIGN 1.E-03 BASIS EVENT Safety Classification (DBE)

REGION of Structures, 1.E-04 Systems, and Individual Risk 1.E-05 Design BEYOND DESIGN Components (SSCs) BASIS EVENT Objective QHO (Prompt)

(BDBE) REGION 1.E-06 1.E-07 Determination of Decreasing Risk EPA PAG Significance Dose Limit Defense-in-depth 1.E-08 (DID) Adequacy 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 TEDE(rem) at the Exclusion Area Boundary 10

LMP Frequency - Consequence Comparison Lowest Dose Middle Dose Largest Dose 11

Reports/Papers LMP Methodology

• Final Report can be used beyond Insights for

• PSA paper the original intent NLWR licensing

• Two pager Operating Communication Reactor Safety

• RMT briefing Insights

• ACRS briefing

• PWROG briefing

• OEDO

• RIC digital exhibit NWLR Licensing Insight

• Understand LMP upfront Opportunities

• 30-day TEDE, EAB, etc.

• NLWR Licensing LMP Challenges

• Risk-Informing CH 15

• Is TEDE the centerline maximum dose? (averaged???) Accident Analysis

• Is evacuation ignored?

• Licensing

• Limitations on accident families?

• Oversight Operating Reactors

• In-line with NLWR guidance

• Consistent with historical PHASE 1 CONCLUSIONS perspective

Communication: Slide 5 PHASE 2 L3PRA A EXPANDED INSIGHTS External Events FLEX ACCIDENT Sequence Review B SEQUENCES Deeper Understanding Uncertainty

RES SUPPORT (LMP use in regulatory framework)

Risk-Informed Now Regulator

• Rely on deterministic PROPOSALS

• Risk-Inform CH 15 analysis

• Rely on risk-insights approaches

• 2 Approaches

• More efficient reviews

• May not explicitly rely on

• NLWR Licensing Support

• Focus on risk-significant risk-insights accidents

• Develop tools to better focus on risk-significant 14aspects

CH 15 Accident Analysis Research Options

• Use LMP F-C chart

• Categorize accidents

• Distance from the F-C Approach 1 target

• Map consequences to Level 1/LERF risk metrics

• Find Correlations Approach 2

• Use Level 1/LERF risk metrics to categorize

NEXT STEPS/QUESTIONS PHASE 2 of the LMP for Operating Reactors A B Program Office Engagement Continue Communication Effort

• Briefings

• Conferences C