Estimation of Fuel Channel Inlet Flow Rate by Noise Analysis

Estimation of fuel channel inlet flow rate was performed, based upon the measurement of the void propagation time between two vertically placed neutron detectors in a BWR core. The procedure of estimation is as follows. First, the time of void propagation between two vertically placed neutron detectors is measured by the cross correlation method. Next, starting from the initial estimation of the coolant inlet flow rate for four fuel channels surrounding the detectors and the pressure drop between upper and lower plenums, the thermal-hydraulic calculation is performed iteratively to obtain the final value of coolant inlet flow rate in agreement with the measured void propagation time. The results show a good agreement with the fuel channel inlet flow value obtained by the theoretical calculation.