The role of quantitative risk assessment in reactor safety

The author discusses quantitative risk assessment and its role in reactor safety. The frequency of man-caused events involving fatalities, as well as natural events are used to assess risk implication. These techniques are a way to rationalize the process of studying and regulating, to concentrate resources where they will likely have the most impact in safety improvement or safety regulation. The application of these techniques occurred after the accident at TMI. The NRC staff undertook a quick study of auxiliary feedwater reliability and thirty-three PWRs, representing 25 different auxiliary feedwater configurations, were studied. The tentative results of the study are shown and indicate that the use of quantitative risk assessment methods is a powerful tool needed for such comparisons