On Line Monitoring of Sensor Failure in Nuclear Power Plant Based on Sequential Probability Ratio Test

Abstract

Abstract The safe and reliable operation of nuclear power plant is inseparable from the integrity of the control system function, and the integrity of the sensor function is the basis for the I&C system to monitor the operation status of nuclear power plant and trigger automatic action. However, there are some shortcomings in the traditional threshold alarm method of nuclear power plant: for example, it is difficult to identify the tiny sensor failure (such as tiny drift) earlier by this method. The threshold of this method is fixed and cannot be adjusted according to the actual situation (such as transient change). This paper introduces the on-line monitoring technology of sensor failure, which plays an important role in reducing the probability of unplanned shutdown and unit design and operation cost. In the future, the on-line monitoring technology of sensor failure has a good application prospect, and the relevant research is of great significance. This paper mainly studies an overall technical scheme of sensor failure monitoring in nuclear power plant. In this paper, the data of the PWR nuclear power plant simulation simulator are used, and the sequential probability ratio test (SPRT) model, a typical failure diagnosis algorithm, is used to establish the sensor condition monitoring model, and the performance of the monitoring model are tested. The results show that the SPRT sensor monitoring model established in this paper has high accuracy, and can effectively monitor the occurrence of tiny drift phenomenon of sensors, and preliminarily verify the feasibility of on-line monitoring technology of sensor failure in PWR nuclear power plant.