Effect Of Radial Heat Flux Distribution On Pressure Drops

Abstract

Pressure drop data were obtained with CANFLEX bundle strings that simulated the radial heat flux distributions (RFDs) of natural uranium (NU) and 1.6 % slightly enriched uranium (SEU) fuel. The experiments were conducted using an axially uniform-heated CANFLEX bundle simulator installed in the vertical test station of the MR-3 heat transfer loop at Chalk River Laboratories. Pressure taps were attached at various locations along the channel and were connected to differential-pressure cells to measure the pressure drop. The measurements covered single-phase and boiling flow with channel powers up to the critical value. Pressure-drop parameters, such as friction factor, onset of significant void and two- phase multiplier, have been evaluated from the pressure drop measurements. Comparisons of these parameters between the CANFLEX bundle strings of NU and 1.6% SEU fuel RFDs are presented. Overall, the RFD effect on single and two-phase pressure-drop parameters is small.