Experimental Study on Boiling Heat Transfer of Fuel Assembly in Fuel Transfer Tube

During the PWR refueling process, the spent fuel assembly is transferred from the reactor building to the spent fuel pool through an underwater tube. In order to obtain the heat transfer characteristics of the spent fuel assembly in the top-corner area of the carrier with poor heat transfer conditions, the experimental study was carried out. The pool boiling heat transfer coefficients of the three fuel rods in the top-corner area of the carrier under different heat flux densities (2 400-20 000 W/m²) were mea-sured and obtained. The boiling heat transfer correlations were obtained by fitting the experimental data. The results can provide a reference for evaluating the thermal safety state and the maximum surface temperature of the fuel assembly during the transportation process in future engineering applications.