The Influence of Spatial Dimension on Task Completion in Human Reliability Analysis: A Pilot Study

In the context of nuclear power plants, human reliability analysis (HRA) is an assessment approach focused on analyzing human error probability in complex systems, minimizing human errors, and increasing safety at nuclear power plants. Both time and location are major influencing factors when it comes to dynamic HRA, because they can easily determine operator success or failure. Despite this, research on these factors is still in its early stages. This pilot study aims to provide preliminary data on four major factors—terrain, distractions, mobility restrictions, and load—to determine the influence of these factors on walking time. Four scenarios were developed to figure out whether movement factors can affect task completion time. By using experimental data, we derived the average walking time and speed under each condition, time increase rate as compared to the regular condition, and the relation of height and speed in given scenarios. These data were linearly regressed to extrapolate time for uncollected data. We found that task performance time varied significantly depending on the determining factor. For example, the distraction scenario drastically increased walking time, while performance changes under factors such as the uneven road were less severe. This research can be used to determine the influence of the spatial dimension during operator walking time, which can help minimize time-related human errors and enhance safety at nuclear power plants.