Three-Dimensional Numerical Analysis of Natural Convection of Compacted Spent Fuel

Three-dimensional natural convection of the compacted spent fuel rod in a pool was studied. A numerical technique was developed based on the conservation of mass, momentum, and energy of a typical flow element in the channel. The coolant flow is laminar and single phase. The decay heat generation from the spent fuel rod was assumed to be a chopped sine curve. Different configurations of the fuel rods were considered. Calculation was done by varying the inlet coolant temperature, decay heat generation, radius of the spent fuel rod, and distance between spent fuel rods. A simple correlation for the Nusselt number, hydraulic diameter, Prandtl number, and Grashof number was obtained.