Axial Power and Coolant Temperature Profiles for a Non Re Entrant Pressure Tube Supercritical Water Cooled Reactor Fuel Channel

Abstract

The axial power and coolanttemperature distributions in a fuel channel of the Generation IV pressuretube supercritical watercooled reactor (PTSCWR) are found using coupled neutronicsthermalhydraulics calculations. The simulations are performed for a channel loaded with a fresh, 78element ThPu fuel assembly. Neutronics calculations are performed using the DONJON diffusion code using twogroup homogenized cross sections produced using the lattice code DRAGON. The axial coolant temperature profile corresponding to a certain axial linear heat generation rate is found using a code developed inhouse at University of Ontario Institute of Technology (UOIT). The effect of coolant density, coolant temperature, and fuel temperature variation along the channel is accounted for by generating macroscopic cross sections at several axial positions. Fixedpoint iterations are performed between neutronics and thermalhydraulics calculations. Neutronics calculations include the generation of twogroup macroscopic cross sections at several axial positions, taking into account local parameters such as coolant temperature and density and average fuel temperature. The coolant flow rate is adjusted so that the outlet temperature of the coolant corresponds to the SCWR technical specifications. The converged axial power distribution is found to be asymmetric, resembling a cosine shape skewed toward the inlet (reactor top).