Abstract:According to vibration monitoring standards IEC61502 and the requirements of nuclear power plant, the vibration detection and analysis technology of nuclear reactor pressure vessel is studied in this paper. The vibration detection method of pressure vessel based on absolute displacement sensor is obtained and the method of analyzing vibration state of pressure vessel with absolute displacement signal is studied. Based on above research and the pressure vessel vibration data of the nuclear power unit 2 in one fuel cycle, the measured vibration data are analyzed, and the vibration amplitude, natural vibration frequency and mode of pressure vessel are obtained. The results show that the vibration of pressure vessel is stable without any abnormality.