Transient analysis of temperature distributions in the hot channel of a VVER-1200 reactor using COMSOL Multiphysics

Abstract

The axial and radial temperature distributions in the hottest channel of a VVER-1200 reactor core were analyzed using Multiphysics coupling heat transfer in solids and fluids and k-epsilon turbulent flow in COMSOL. The thermal and geometric properties of the fuel rod were modeled to closely resemble those of a VVER-1200 reactor fuel rod, incorporating the internal cavity, fuel meat, gas gap, cladding, and coolant layers. The volumetric heat generation rate (VHGR) was calculated from the linear heat generation rate and then multiplied by the peaking factors and nonuniformity coefficients. A heat flux was applied to the coolant wall, along with a VHGR heat source of approximately 9.2 · 10 8 W/m³ on the fuel meat. The maximum centerline temperature in the hottest channel was found to be approximately 1804 °C