Noise analysis of anomalous power fluctuations in HWRR-2

Abstract This paper describes the neutron noise analysis at HWRR-2. In case of normal operating, there are two dominant peaks on the APSD at about 1 Hz and 2.6Hz, the first one is corresponding to the vibration of fuel elements, other one may be induced by the vibration of control rods. At anomalous state, there is an isolate peak on the APSD at about 0.7Hz, it has been demonstrated that this peak is induced by the abnormal vibration of the experimental channel in the heavy water reflector.