Construction and evaluation of fault detection network for signal validation

The paper presents a methodology which performs evaluation and construction of a sensor failure detection network for nuclear power plant signal validation. The network is arranged in a fault tree structure which consists of sensors, mathematical models for sensor relations and decision/estimators derived form parity relations. The evaluation scheme performs a logic state analysis to categorize critical signals and the associated sensors. The construction scheme cooperates with the evaluation scheme to build a detection network automatically using a rule-based algorithm. The package is implemented on a microcomputer and is demonstrated for the nuclear steam supply system of a PWR