Discrete event simulation as a tool to determine necessary nuclear power plant operating crew size

There are not always sufficient resources or time available to identify human factors issues early enough for development of detailed technical bases using empirical experimentation with human subjects. Consequently, analytical approaches are needed to augment the experimental approach for human factors regulatory decision making at the US Nuclear Regulatory Commission. One analytical approach, computer modeling of human performance, is being investigated by the NRC Office of Nuclear Regulatory Research. As an example of the types of supporting research required, we discuss two specific studies pertaining to the use of Micro Saint, a discrete event simulation package, as a means of evaluating the effects of crew size on safety in a nuclear power plant setting. Both studies provided data that permit an evaluation of the practicality and validity of using models built in Micro Saint for the specific purpose of studying staffing issues, as well as the value of modeling of human performance in general.