DPRL: a language for representation of operation and safety maintenance procedures of nuclear power plants

Abstract

1.0 Introduction The task of operation and safety maintenance performed by the reactor operator in a nuclear power plant is a complex knowledge based task and has to be done within given time constraints. The two essential tasks in the overall task are: (1) monitoring plant data to detect abnormal functioning of the plant, and (2) identifying and executing procedures to restore normal operation while maintaining plant safety. The knowledge required for both these tasks is available from the plant operating manuals, and the plant operators’ training and experience. Our objective in this paper is to describe the knowledge representation scheme developed for the second task. The objective of the first task is to detect known malfunction states by monitoring the plant conditions. The second task is initiated after the first task, i.e. after the known malfunction states have been detected. The objective of second task is to execute control procedures to: (1) restore normal plant operation, and (2) maintain plant safety. The plant environment on which the control procedures operate is dynamic and unpredictable and given the time limitations, it is not always possible to restore the normal operation and maintain safety simultaneously. It is for this reason that the plant safety of a nuclear power plant is defined independent of normal operation. The plant safety can be maintained if certain critical parameters remain within prescribed limits, whether or not the plant is producing power at its normal ratings. Because of the independence of safety and operation the actions required to