Modeling and quantification of team performance in human reliability analysis for probabilistic risk assessment

Probabilistic Risk Assessment (PRA) and Human Reliability Analysis (HRA) are important technical contributions to the United States (U.S.) Nuclear Regulatory Commission's (NRC) risk-informed and performance based approach to regulating U.S. commercial nuclear activities. Furthermore, all currently operating commercial nuclear power plants (NPPs) in the U.S. are required by federal regulation to be staffed with crews of operators. Yet, aspects of team performance are underspecified in most HRA methods that are widely used in the nuclear industry. Furthermore, there are a variety of "emergent" team cognition and teamwork errors (e.g., communication errors) that are 1) distinct from individual human errors, and 2) important to understand from a PRA perspective. The lack of robust models or quantification of team performance is an issue that affects the accuracy and validity of HRA methods and models, leading to significant uncertainty in estimating human error probabilities (HEPs). This paper describes research designed to model and quantify team dynamics and teamwork within NPP control room crews for risk informed applications, thereby improving the technical basis of HRA, which improves the risk-informed approach the NRC uses to regulate the U.S. commercial nuclear industry.