ML20080M178
| ML20080M178 | |
| Person / Time | |
|---|---|
| Issue date: | 03/23/2020 |
| From: | Thomas Aird, M'Lita Carr, Mark Fuhrmann, Joseph Kanney, Elena Yegorova Office of Nuclear Regulatory Research |
| To: | Office of Nuclear Regulatory Research |
| T. Aird | |
| Shared Package | |
| ML20080M135 | List: |
| References | |
| Download: ML20080M178 (21) | |
Text
Overview of NRCs Probabilistic Flood Hazard Assessment Research Program Thomas Aird*, Meredith Carr, Mark Fuhrmann, Joseph Kanney, Elena Yegorova Fire and External Hazards Analysis Branch Division of Risk Analysis Office of Nuclear Regulatory Research 5th Annual PFHA Research Workshop NRC HQ, Rockville, MD February 19 - 21, 2020 1
Outline
- Objectives
- Key Challenges
- Research Approach
- Selected Projects
- Future Directions 2
PFHA Research Objectives
- Address significant gap in technical basis for guidance for probabilistic assessment of external hazards
- Probabilistic: seismic, high winds
- Deterministic: flooding
- Develop resources, tools and selected guidance
- Support risk-informed licensing and oversight activities associated with flooding hazards and consequences
- Licensing and oversight in operating reactor program
- Design basis flood hazard assessments for new facilities
- Readiness for licensing of advanced reactors 3
Key Challenges
- Hazard Curve Development
- Range of annual exceedance probabilities (AEPs)
- Moderately rare to extreme floods
- Multiple flooding mechanisms
- Coincident and correlated mechanisms
- Uncertainty characterization and Magnitude estimation
- Aleatory (e.g. storm recurrence rates)
- Epistemic (e.g. model structure, parameters)
- Fragility Curve Development Failure Probability
- Information on reliability of flood protection features and procedures is sparse
- Cliff-edge effects Load Intensity 4
Phased Approach
- Phase 1 (FY15-FY19)
- Technical basis research
- Phase 2 & 3 (FY20-FY22)
- Selected draft guidance documents
- Perform pilot studies
- Finalize guidance 5
Leverage Available Flood Information PFHA Modeling Phase 1 Frameworks Improved Modeling Technical Basis Reliability of Flood Protection Projects Dynamic and Nonstationary Processes 6
Leverage Available Flood Information PFHA Modeling Phase 1 Frameworks Improved Modeling Technical Basis Reliability of Flood Protection Projects Dynamic and Nonstationary Processes 7
Leverage Available Flooding Information
- Completed (continue with updates/maintenance)
- Application of State-of-Practice Flood Frequency Analysis Methods and Tools (USGS)
- Completed - USGS Scientific Investigation Report
- https://pubs.er.usgs.gov/publication/sir20175038
- Extreme Precipitation Estimates in Orographic Regions (USBR)
- Completed - NUREG/CR report in publication
- Technical Basis for Extending Frequency Analysis Beyond Current Consensus Limits (USBR)
- In progress (completion expected in FY20) 8
Leverage Available Flooding Information
- Eastern US Riverine Flood Geomorphology Feasibility Study (USGS)
- Completed - USGS Scientific Investigations Report
- Eastern US Riverine Flood Geomorphology Comprehensive Study (USGS)
-In progress (completion expected FY20)
- Framework for Technical Review of Paleoflood Information (USGS)
-In progress (completion expected FY20)
- Workshop summary: ML19200A281
- Application of Point Precipitation Estimates to Watersheds (ORNL)
-Completed (NUREG/CR report in publication) 9
Leverage Available Flood Information PFHA Modeling Phase 1 Frameworks Improved Modeling Technical Basis Reliability of Flood Protection Projects Dynamic and Nonstationary Processes 10
PFHA Modeling Frameworks
- Probabilistic Flood Hazard Assessment Framework Development (USACE)
- In progress (completion expected FY20)
- Structured Hazard Assessment Committee Process for Flooding (SHAC-F) for LIP & Riverine Flooding (PNNL)
- In progress (completion expected FY20)
- Development of SHAC-F for Coastal Flooding (PNNL &
USACE)
- In progress (completion expected FY20)
- Methods for Estimating Joint Probabilities of Coincident and Correlated Flooding Mechanisms for Nuclear Power Plant Flood Hazard Assessments (ORNL)
- In progress (completion expected FY20)
- Task 1 (Literature review) completed
- Task 2 (Critical Assessment of Selected Methods and Approaches) Completed.
11
Leverage Available Flood Information PFHA Modeling Phase 1 Frameworks Improved Modeling Technical Basis Reliability of Flood Protection Projects Dynamic and Nonstationary Processes 12
Improved Modeling
- Numerical Modeling of Local Intense Precipitation Processes (USGS/UC Davis)
- Completed - NUREG-CR report in publication
- Peer-reviewed papers: Mure-Ravaud, et al. (2019a,b) https://www.sciencedirect.com/science/article/pii/S0048969719306734
- https://www.sciencedirect.com/science/article/pii/S0048969719306291
- Quantifying Uncertainties in Probabilistic Storm Surge Models (USACE)
- In Progress (completion expected FY20)
- Task 1 (Literature Review) Completed. ERDC/CHL SR-19-1
- Task 2 (Storm Recurrence Rate Models) Completed. ERDC/CHL TR-19-4
- Erosion Processes in Embankment Dams (USBR)
- Completed - NUREG-CR report in publication
- Convection-Permitting Modeling for Intense Precipitation Processes (NCAR)
- In Progress (completion expected FY21) 13
Leverage Available Flood Information PFHA Modeling Phase 1 Frameworks Improved Modeling Technical Basis Reliability of Flood Protection Projects Dynamic and Nonstationary Processes 14
Reliability of Flood Protection
- Modeling Plant Response to Flooding Events (INL)
- Completed. NUREG/CR report in publishing
- Effects of Environmental Factors on Manual Actions for Flood Protection and Mitigation at Nuclear Power Plants (PNNL)
- Completed. NUREG/CR report in publication process
- Critical Review of the State of Practice in Probabilistic Risk Assessment for Dams (ORNL, UMD)
- Completed. ORNL report available at https://www.osti.gov/biblio/1592163-current-state-practice-dam-safety-risk-assessment
- Performance of Flood Penetration Seals at NPPs (Fire Risk Management, Inc.)
- Completed. NUREG report in publication process
- Flood Barrier Testing Strategies (INL/ISU)
- In Progress. Public workshop to be held March 12 - 13 15
Leverage Available Flood Information PFHA Modeling Phase 1 Frameworks Improved Modeling Technical Basis Reliability of Flood Protection Projects Dynamic and Nonstationary Processes 16
Dynamic and Nonstationary Processes
- Regional Climate Change Projections: Potential Impacts to Nuclear Facilities (PNNL)
- Year 1 (CONUS) - Complete
- published as a PNNL report (PNNL-24868)
- Year 2 (Southeast US) - Complete
- published as a PNNL report (PNNL-26226)
- Year 3 (Midwest US) - Complete
- published as a PNNL report (PNNL-27452 Rev1)
- Year 4 (Northeast US) - Complete
- published as a PNNL report (PNNL-29079) 17
Future Directions for PFHA Phase 1 Phase 2 Phase 3 Technical Application Pilot Projects Inform & update Guidance Basis Projects 18
Future Directions for PFHA Phase 1 Phase 2 Phase 3 Technical Application Pilot Projects Inform & update Guidance Basis Projects 19
Phase 2 Pilot Studies Objective: Synthesize results from technical basis research
- Multiple flooding mechanism contribution to hazard curves
- Quantify key aleatory variabilities and epistemic uncertainties LIP Flooding PFHA Pilot (PNNL)
- Pilot study to inform development of guidance for probabilistic assessment of flooding hazards at NPPs due to local intense precipitation events Riverine PFHA Pilot (USACE/HEC)
Coastal Flooding Pilot PFHA Pilot (USACE/ERDC) 20
Phase 3 (FY22-?)
Phase 1 Phase 2 Phase 3 Technical Application Pilot Projects Inform & update Guidance Basis Projects
- Revise guidance documents based on pilots
- Stakeholder & Public Interactions
- Finalize guidance Questions?
Contact:
joseph.kanney@nrc.gov 21