Method and device of inspecting nuclear power plants

Purpose: To monitor the operation performance for each of control systems thereby enabling early abnormality detection in on-line manner and with no external disturbances to a nuclear power plant during its operation. Method: The presence or absence of abnormality is judged taking notice of fluctuations around mean values contained in usual measuring signals in a nuclear power plant (noise component) utilizing the mutual correlation functions calculated as the result of statistical analysis for the noise components and using operation delays and peak values for the equipments corresponding to the peak positions of the mutual correlation functions. Specifically, mutual correlation functions between control signals and plant status signals are determined and the peak levels or peak generation times thereof are compared with those in the normal states for inspecting the plant. (Ikeda, J.)