ABSTRACT
In nuclear power plants, man-machine interfaces (MMl) are being transformed fi·om conventional panels to computer workstations. Therefore, operators' behavior in modem main control room differs from what they do in a conventional one. This paper makes a comparison between digital instrumentation & control system and analog one in the perspective of system characteristics, man-machine interface and operators themselves. Main cognitive tasks and possible failure modes of operators'
monitoring and detection, situation assessment, response planning and response implementation in emergency situation are analyzed. In addition, based on the study on the operators who are receiving a training program on a reference experimental Chinese digital simulator, main influencing factors which would lead to possible human errors are presented.
