ABSTRACT
It is estimated that from 20 to 70 per cent of all system failures at nuclear power plants are caused by human error (Arkin and Handler, 1989; Bell and O’Reilly, 1989; Bento, 1990; Dennig and O’Reilly, 1987; Lam and Leeds, 1988; O’Reilly and Plumlee, 1988; Skof, 1990; Wu and Hwang, 1989; Zech, 1988). Despite the widely recognised impact of human error
and the various efforts undertaken to reduce its occurrence, human error probabilities (HEPs) in nuclear power plants are not necessarily decreasing (Kameda and Kabetani, 1990). Thus, there is a need to develop improved methods for understanding human errors and the conditions that lead to such errors. Furthermore, it has been estimated that even relatively small improvements in HEPs can result in highly significant improvements in many accident sequences (Samanta, Wong, Higgins, Haber, and Luckas, 1988). In any work-setting there is a multitude of sources that can contribute to human error rates. For example, in nuclear power settings, plant type (pressurised water reactor versus boiling water reactor) and organisational climate (plant management’s relative concern for safety versus production) are but two factors on which nuclear power plants differ that might have substantial influence on task HEP. Similarly, within the same plant, error rates may vary for different types of jobs (control room operator versus instrument and control technician). At a more ‘micro’ level of analysis, a critical source of human error may be the abilities required to perform the tasks of the job. For example, cognitive abilities and perceptual-motor abilities have been proposed as important determinants of performance in nuclear power plants. However, not much attention has been paid to establishing empirically whether this view is true, or whether there are particular cognitive or perceptual-motor ability requirements of job tasks or some combination of ability requirements that contribute significantly to producing human error in performing job tasks. The research programme described in this chapter addresses such questions.
