Development of an Integrated Decision Support System to Aid the Cognitive Activities of Operators in Main Control Rooms of Nuclear Power Plants

In safety critical systems, especially in nuclear power plants (NPPs), human error has been introduced as one of the serious causes of accidents. In order to prevent human errors, many efforts have been made to improve main control room (MCR) interface designs and to develop decision support systems that allow convenient MCR operation and maintenance. In this paper, an integrated decision support system to aid the cognitive process of operators is proposed for advanced MCRs in future NPPs. This work suggests support system design considered an operator's cognitive process. Various kinds of support systems for advanced MCRs have been developed or are in development. Therefore, a design basis regarding what kinds of support systems are appropriate for MCR operators is necessary. The proposed system supports not merely a particular task, but also the entire operation process based on a human cognitive process model. It supports the operator's entire cognitive process by integrating support systems that support each cognitive activity. Furthermore, two decision support systems are developed. The fault diagnosis advisory system is to make the task of fault diagnosis easier and to reduce errors by quickly suggesting likely faults based on the highest probability of their occurrence. The operation validation system is to provide an advisory function to supervise and validate the operator's actions during abnormal environments