A knowledge-based operator advisor system for integration of fault detection, control, and diagnosis to enhance the safe and reliable operation of nuclear power plants

A Knowledged-Based Operator Advisor System has been developed for enhancing the complex task of maintaining safe and reliable operation of nuclear power plants. The system is developed using a Generic Tasks Methodology, which allows representation of domain knowledge at a high level according to the task. The operator's activities for maintaining the safe and reliable operation of a nuclear power plant have been organized into the four tasks of data interpretation for abstracting high level information from sensor data, plant state monitoring for identification of faults, plan execution for controlling the faults, and diagnosis for determination of root causes of faults. These tasks have been implemented as four modules of an Integrated Operator Advisor System.; The Operator Advisor System is capable of identifying the abnormal functioning of the plant in terms of: (1) deviations from normality, (2) pre-enumerated abnormal events, and (3) safety threats. The classification of abnormal functioning into the three categories of deviations from normality, abnormal events, and safety threats allows the detection of faults at three levels of: (1) developing faults, (2) developed faults, and (3) safety threatening faults.; After the identification of abnormal functioning the system will identify the procedures to be executed to mitigate the consequences of abnormal functioning and will help the operator by displaying the procedure steps and monitoring the success of actions taken. The system also is capable of diagnosing the root causes of abnormal functioning. The identification, and diagnosis of root causes of abnormal functioning are done in parallel to the task of procedure execution, allowing the detection of more critical safety threats while executing procedures to control abnormal events.; The system is designed to operate in real-time and can change its focus of attention depending on current priorities. The system also is designed to provide defense-in-depth in situations when there are no available procedures or the available procedures cannot be successful.; The system has been tested with a scenario and a limited number of procedures for abnormal events and safety threats. The system responds as expected according to the procedures and knowledge incorporated in it.