Thermal‐hydraulic analysis of UO2 and MOX fuel considering different cladding materials at various burnup levels in pressurized water reactor

Abstract

AbstractThermal analysis of fuel elements with UO2 and mixed‐oxide (MOX) fuels at different fuel burnup levels has been performed analytically and by simulation using ANSYS. Results showed that UO2 incurred a lower fuel temperature than MOX under all conditions. Higher fuel element temperatures were obtained for higher levels of burnup for UO2 fuel. For MOX fuel, higher temperatures were obtained for low and high burnup fuel. Radial temperature, thermal gradient, and thermal heat flux were determined across reactor pressure vessel (RPV), demonstrating the highest value at the center of the RPV. The maximum linear power density was determined for UO2 and MOX, showing that using UO2 fuel at 2 at% burnup rendered the highest allowable linear power density. Furthermore, the transient analysis showed that there was a small rise in fuel temperature for a decrease in mass flow rate from 100% to 60% followed by a rapid increase in temperature for further reduction in flow rate.