An algorithm for enhancing spatiotemporal resolution of probabilistic risk assessment to address emergent safety concerns in nuclear power plants. (May 2019)

• Record Type: Journal Article
• Authors: Bui, Ha; Sakurahara, Tatsuya; Pence, Justin; Reihani, Seyed; Kee, Ernie; Mohaghegh, Zahra
• Is Part Of: Reliability engineering & system safety. Volume 185(2019)
• Page Start: 405
• Page End: 428
• Publication Date: 2019-05
• Subjects: Integrated Probabilistic Risk Assessment (I-PRA) -- Generic Safety Issue 191 (GSI-191) -- Nuclear promise -- Fire PRA -- Risk-informed regulation -- Dynamic PRA; ADAPT Analysis of Dynamic Accident Progression Trees -- ADS Accident Dynamic Simulation -- BWR Boiling Water Reactor -- CAD Computer-Aided Design -- CASA Containment Accident Stochastic Analysis -- CCBE Common Cause Basic Event -- CCCMT Continuous Cell-To-Cell-Mapping Technique -- CCF Common Cause Failure -- CDF Core Damage Frequency -- CET Continuous Event Tree -- CFAST Consolidated Model of Fire Growth and Smoke Transport -- CFD Computational Fluid Dynamics -- CFR Code of Federal Regulations -- CHLE Chemical Head Loss Experiments -- CSHL Clean Strainer Head Loss -- CSS Containment Spray System -- DDET Discrete Dynamic Event Tree -- DEGB Double Ended Guillotine Break -- DET Dynamic Event Tree -- DETAM Dynamic Event Tree Analysis Method -- DYLAM Dynamic Logical Analytical Methodology -- ECCS Emergency Core Cooling System -- EMRALD Event Modeling Risk Assessment using Linked Diagrams -- ERM Enterprise Risk Management -- ET Event Tree -- FDS Fire Dynamics Simulator -- FLEX Diverse and Flexible Coping Strategy -- FSM Failure Simulation Module -- FT Fault Tree -- GDC General Design Criteria -- GIM Global Importance Measure -- GL Generic Letter -- GSI-191 Generic Safety Issue 191 -- HHSI High Head Safety Injection -- HRR Heat Release Rate -- HRA Human Reliability Analysis -- IE Initiating Event -- IM Importance Measure -- I-PRA Integrated Probabilistic Risk Assessment -- KPM Key Performance Measure -- LERF Large Early Release Frequency -- LHS Latin Hypercube Sampling -- LHSI Low Head Safety Injection -- LN Logic Node -- LOCA Loss of Coolant Accident -- LWR Light Water Reactor -- MCDET Monte Carlo Dynamic Event Tree -- MCS Minimal Cut Set -- MELCOR Methods for Estimation of Leakages and Consequences of Releases -- NEI Nuclear Energy Institute -- NPP Nuclear Power Plant -- NPSH Net Positive Suction Head -- NRC U.S. Nuclear Regulatory Commission -- PPoF Probabilistic Physics-of-Failure -- PRA Probabilistic Risk Assessment -- PWR Pressurized Water Reactor -- RAVEN Reactor Analysis and Virtual Control Environment -- RELAP Reactor Excursion and Leak Analysis Program -- ROM Reduced Order Model -- RoverD Risk-informed Over Deterministic -- RWST Reactor Water Storage Tank -- SCAIS Simulation Code System for Integrated Safety Assessment -- SimPRA Simulation-based Probabilistic Risk Assessment -- S-IPM Simulation-Informed Probabilistic Methodology -- SoTeRiA Socio-Technical Risk Analysis -- SRM Staff Requirements Memorandum -- SSCs Structures, Systems, and Components -- TH Thermal Hydraulic -- TRACE TRAC/RELAP Advanced Computational Engine -- ZOI Zone of Influence; Reliability (Engineering) -- Periodicals; System safety -- Periodicals; Industrial safety -- Periodicals; Fiabilité -- Périodiques; Sécurité des systèmes -- Périodiques; Sécurité du travail -- Périodiques; 620.00452
• DOI: 10.1016/j.ress.2019.01.004
• Languages: English
• ISSNs: 0951-8320

Abstract

Highlights: Theoretical foundations for the incorporation of time and space into Probabilistic Risk Assessment (PRA). Integrated PRA (I-PRA) methodology to add realism to risk estimations while avoiding significant changes to the plant PRA structure and the associated costs. Explicit incorporation of time and space into underlying models of the events in the plant PRA. An algorithm that helps execute I-PRA in a way to gradually enhance spatiotemporal resolution of the plant PRA to efficiently address emergent safety concerns. The algorithm is illustrated with Fire PRA and Generic Safety Issue 191 (GSI-191) applications. Abstract: Emergent safety concerns often involve complex spatiotemporal phenomena. In addressing these concerns, the classical Probabilistic Risk Assessment (PRA) of Nuclear Power Plants (NPPs) has limitations in generating the required resolution for risk estimations. The existing dynamic PRAs have yet to demonstrate their feasibility for implementation in a plant. In addition, due to the widespread use of classical PRA in the nuclear industry and by the regulatory agency, a transition to a fully dynamic PRA would require a significant investment of resources. As a more feasible alternative, the authors have developed the Integrated PRA (I-PRA) methodology to add realism to risk estimations by explicitly incorporating time and space into underlying models of the events in the plant PRA while avoiding significant changes to its structure. In I-PRA, the failure mechanisms associated with the areas of concern (e.g., fire, Generic Safety Issue 191) were modeled in separate simulation modules, which were then integrated with the plant PRA through a probabilistic interface. This paper (i) provides theoretical foundations for the incorporation of time and space into PRA and (ii) introduces an algorithm that helps execute I-PRA in a way to gradually enhance spatiotemporal resolution of plant PRAs to efficiently address emergent safety concerns.