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​​​​​​​​​​​​Risk-Informed Multiphysics Best Estimate Plus Uncertainties


Goal

Uncertainty quantification in modeling and simulation is an important step in increasing confidence in the safety analysis of a nuclear power plant. The goal of this research was to improve the multiphysics uncertainty quantification capabilities of RELAP5-3D, ultimately decreasing over-conservatisms during safety margins assessment. ​

Outcome

The research improved uncertainty analysis capability in RELAP5-3D, the INL best-estimate nuclear thermal-hydraulic computer code, focusing on the reflooding phase of large break loss-of-coolant accident. Relevant closure laws of RELAP5-3D were modified to allow codes user to perturb their main parameters using assigned probabilities distribution functions. Idaho National Laboratory's risk-analysis tool RAVEN, coupled with RELAP5-3D code, were used to demonstrate phase of the research project,​ and applied to the analysis of two reflood experiments. The methodology was widely used in other projects in the Risk-Informed Systems Analysis pathway​. 

​​​Reports​

 

 

Plant Integral Risk-informed System Health Program, INL/EXT-19-5580855436Plant Integral Risk-informed System Health Program, INL-EXT-19-55808Plant Integral Risk-informed System Health Program, INL-EXT-19-5580810/1/2019 8:01:50 AMINL-EXT-19-55808 Light Water Reactor Sustainability Program Plant Integral Risk-informed System Health Program September 2019 U.S. Department of Energy Office of Nuclear Energy 1023https://lwrs.inl.gov/RiskInformed Safety Margin Characterization/Forms/AllItems.aspxpdfFalsepdf
RISA Pathway Industry Application Pilot Demonstration Projects - Edition 2019, INL/EXT-19-5444955367Risk-Informed Systems Analysis (RISA) Pathway Industry Application Pilot Demonstration Projects - Edition 2019, INL/EXT-19-54449Risk-Informed Systems Analysis (RISA) Pathway Industry Application Pilot Demonstration Projects - Edition 2019, INL/EXT-19-544496/28/2019 6:13:16 PMINL/EXT-19-54449 Light Water Reactor Sustainability Program Risk-Informed Systems Analysis (RISA) Pathway Industry Application Pilot Demonstration Projects - Edition 2019 430https://lwrs.inl.gov/RiskInformed Safety Margin Characterization/Forms/AllItems.aspxpdfFalsepdf
A Strategic Approach to Employ Risk-Informed Methods to Enable Margin Recovery of Nuclear Power Plants Operating Margins, INL/EXT-18-5149155517A Strategic Approach to Employ Risk-Informed Methods to Enable Margin Recovery of Nuclear Power Plants Operating Margins, INL/EXT-18-51491A Strategic Approach to Employ Risk-Informed Methods to Enable Margin Recovery of Nuclear Power Plants Operating Margins, INL/EXT-18-5149110/1/2018 3:10:49 PMU.S. Department of Energy Office of Nuclear Energy This information was prepared as an account of work sponsored by an agency of the U.S. Government The focus of this report is to 241https://lwrs.inl.gov/RiskInformed Safety Margin Characterization/Forms/AllItems.aspxpdfFalsepdf
RISA Industry Use Case Analysis, INL/EXT-18-5101255368RISA Industry Use Case Analysis, INL/EXT-18-51012RISA Industry Use Case Analysis, INL/EXT-18-510129/4/2018 4:07:09 PMLight Water Reactor Sustainability (LWRS) Program Ronaldo Szilard, Hongbin Zhang, Stephen Hess, John Gaertner Diego Mandelli, Steven Prescott, Mitchell Farmer 363https://lwrs.inl.gov/RiskInformed Safety Margin Characterization/Forms/AllItems.aspxpdfFalsepdf
Multi-Hazard Advanced Seismic Probabilistic Risk Assessment Tools and Applications, INL/EXT-16-400555432Multi-Hazard Advanced Seismic Probabilistic Risk Assessment Tools and Applications, INL/EXT-16-4005Multi-Hazard Advanced Seismic Probabilistic Risk Assessment Tools and Applications, INL/EXT-16-400510/6/2016 2:10:32 PMINL/EXT-16- 40055 Light Water Reactor Sustainability Program Multi-Hazard Advanced Seismic Probabilistic Risk Assessment Tools and Applications Justin L. Coleman Chandu Bolisetti 682https://lwrs.inl.gov/RiskInformed Safety Margin Characterization/Forms/AllItems.aspxpdfFalsepdf
R&D Plan for RISMC Industry Application #1: ECCS/LOCA Cladding Acceptance Criteria, INL/EXT-16-3823155766R&D Plan for RISMC Industry Application #1: ECCS/LOCA Cladding Acceptance Criteria, INL/EXT-16-38231R&D Plan for RISMC Industry Application #1: ECCS/LOCA Cladding Acceptance Criteria, INL/EXT-16-382314/25/2016 9:36:35 PMINL/EXT-16-38231 Light Water Reactor Sustainability Program R&D Plan for RISMC Industry Application #1: ECCS/LOCA Cladding Acceptance Criteria Ronaldo Szilard Hongbin Zhang Aaron 293https://lwrs.inl.gov/RiskInformed Safety Margin Characterization/Forms/AllItems.aspxpdfFalsepdf
Industry Application Emergency Core Cooling System Cladding Acceptance Criteria Early Demonstration, INL/EXT-15-3654155918Industry Application Emergency Core Cooling System Cladding Acceptance Criteria Early Demonstration, INL-EXT-15-36541Industry Application Emergency Core Cooling System Cladding Acceptance Criteria Early Demonstration, INL-EXT-15-365419/30/2015 8:43:30 PMINL/EXT-15-36541 Light Water Reactor Sustainability Program Industry Application Emergency Core Cooling System Cladding Acceptance Criteria Early Demonstration Ronaldo H Szilard 552https://lwrs.inl.gov/RiskInformed Safety Margin Characterization/Forms/AllItems.aspxpdfFalsepdf
Industry Application External Hazard Analyses Problem Statement, INL/EXT-15-3610155916Industry Application External Hazard Analyses Problem Statement, INL-EXT-15-36101Industry Application External Hazard Analyses Problem Statement, INL-EXT-15-361017/31/2015 8:41:07 PMRonaldo H Szilard, Justin Coleman, Curtis L Smith, Steven Prescott, Annie Kammerer, Robert Youngblood, Chad Pope This information was prepared as an 230https://lwrs.inl.gov/RiskInformed Safety Margin Characterization/Forms/AllItems.aspxpdfFalsepdf
RISMC Advanced Safety Analysis Project Plan FY2015–FY2019, INL/EXT-14-3318655186RISMC Advanced Safety Analysis Project Plan FY2015–FY2019, INL-EXT-14-33186RISMC Advanced Safety Analysis Project Plan FY2015–FY2019, INL-EXT-14-331869/29/2014 10:13:29 PMThis information was prepared as an account of work sponsored by an agency of the U.S. Government Neither the U.S. Government nor any agency thereof, nor any of their employees 195https://lwrs.inl.gov/RiskInformed Safety Margin Characterization/Forms/AllItems.aspxpdfFalsepdf
Enhanced Severe Transient Analysis for Prevention Technical Program Plan, INL/EXT-14- 3322855198Enhanced Severe Transient Analysis for Prevention Technical Program Plan, INL/EXT-33228Enhanced Severe Transient Analysis for Prevention Technical Program Plan, INL/EXT-332289/29/2014 6:29:19 PMThis information was prepared as an account of work sponsored by an agency of the U.S. Government Neither the U.S. Government nor any agency thereof, nor any of their employees 222https://lwrs.inl.gov/RiskInformed Safety Margin Characterization/Forms/AllItems.aspxpdfFalsepdf

​For more information, contact

Svetlana (Lana) Lawrence
Risk-Informed Systems Analysis, Pathway Lead
Idaho National Laboratory
Using BEPU  

Concept of safety margins describing the best estimate plus uncertainty (BEPU) method's benefits. The best-estimated value with an uncertainty range is the closest to the actual value. The benefit is improving the safety margin compared to conservative value.