The action characterization matrix: A link between HERA (Human Events Reference for ATHEANA) and ATHEANA (a technique for human error analysis)

Abstract

The Technique for Human Error Analysis (ATHEANA) is a newly developed human reliability analysis (HRA) methodology that aims to facilitate better representation and integration of human performance into probabilistic risk assessment (PRA) modeling and quantification by analyzing risk-significant operating experience in the context of existing behavior science models. The fundamental premise of ATHEANA is that error-forcing contexts (EFCs), which refer to combinations of equipment/material conditions and performance shaping factors (PSFs), set up or create the conditions under which unsafe actions (UAs) can occur. ATHEANA is being developed in the context of nuclear power plant (NPP) PRAs, and much of the language used to describe the method and provide examples of its application are specific to that industry. Because ATHEANA relies heavily on the analysis of operational events that have already occurred as a mechanism for generating creative thinking about possible EFCs, a database, called the Human Events Reference for ATHEANA (HERA), has been developed to support the methodology. Los Alamos National Laboratory`s (LANL) Human Factors Group has recently joined the ATHEANA project team; LANL is responsible for further developing the database structure and for analyzing additional exemplar operational events for entry into the database. The Action Characterization Matrix (ACM) is conceived as a bridge between the HERA database structure and ATHEANA. Specifically, the ACM allows each unsafe action or human failure event to be characterized according to its representation along each of six different dimensions: system status, initiator status, unsafe action mechanism, information processing stage, equipment/material conditions, and performance shaping factors. This report describes the development of the ACM and provides details on the structure and content of its dimensions.