Interview to Questionnaire Comparison of Workload Measurement on Nuclear Power Plant Tasks

AbstractNuclear Power Plant (NPP) Main Control Room (MCR) operators oversee proper functioning of the facilities, including the controls to maintain the nuclear reactor. At least three operators, two reactor operators (ROs) and one senior reactor operator (SROs), are required for safe operations. The level of detail involved in performing the duties required of a nuclear power plant operator can result in a considerable amount of workload. Given the responsibility for safe operations, it is critical that operator workload is understood to provide accurate information about potential errors. Workload is the perceived amount of demand associated with executing a given task [1]. In light of resource theory, workload is the amount of resources required to perform a task and generally, it is accepted that as workload increases, performance decreases, thus errors are more likely and safety can be jeopardized [2]. Systematic experimentation for identifying levels of workload associated with NPP MCR tasks has been limited and the studies conducted are not without their limitations [3–5]. To understand the level of workload experienced by NPP operators, an experiment was conducted using “experienced” participants. An experienced participant in the present discussion is one that completed a rigorous training curriculum for three common task types encountered during main control room operations. The task types as adapted from [6] were checking, response implementation, and detection [7]. Three experienced participants served in the role of an RO in the present experiment, participating in 27 sessions each, and completing the three task types during each session. Each task type consisted of a block of four tasks. The NASA-Task Load Index was administered after each task type block and interviews were conducted at a later time. Results indicated that the detection task was the most demanding. The implications of measurement fit for workload assessment in a nuclear power plant domain are discussed