Nuclear Plant Control Room Operator Modeling Within the ADS-IDAC, Version 2, Dynamic PRA Environment: Part 1 - General Description and Cognitive Foundations

摘要

Dynamic simulation-based approaches for probabilistic risk assessment (PRA) offer several key advantages over traditional "static" techniques such as traditional event tree-fault tree based methods. For example, dynamic simulation approaches can more realistically represent event sequence and timing, provide a better representation of thermal hydraulic success criteria, and permit more detailed modeling of operator response. Version 2.0 of the Accident Dynamics Simulator paired with the Information, Decision, and Action cognitive model in a Crew context (ADS-IDAC) is one such dynamic method that shows promise for supporting nuclear power plant PRAs and other risk-informed applications. By linking a realistic nuclear plant thermal-hydraulic model with a crew behavior model, ADS-IDAC creates a rich simulation environment. The crew behavior model describes the operators' preferences and tendencies, knowledge, and situation-response rules. ADS-IDAC generates a discrete dynamic event tree (DDET) by applying simple branching rules that reflect variations in crew responses to plant events and system status changes. Branches can be generated to simulate a variety of operator behaviors, including procedure execution speed and adherence, evolving situational assessments, and variations in plant control preferences. This of the first of two papers in this volume and provides an overview of the ADS-IDAC Version 2.0 simulation platform and a description the cognitive foundations underpinning the operator human performance model.