Thermal Transport Behavior of Graphite Coated Thorium Dioxide

At present 14% of the world’s energy is generated from nuclear reactors, while in the United States this is 20% of all energy produced. As the world moves to more renewable and cleaner energy sources, nuclear energy becomes a more favorable candidate for future energy requirements. The safety and efficiency in nuclear operation strongly depends on the enhancement of the thermal conductivity of fuel materials. In this work, towards development of accident tolerant fuel,the effects of graphite coating to thorium dioxide (thoria) fuel material is analyzed using Finite Element Analysis(ANSYS). The thorium dioxide used a thermal conductivity of 20.8 W/m-K and the graphite used a 450 W/m-K. With the added graphite layer, thoria exhibits an improvement in the heat flux. The engineering scale simulations are conducted at different mesh sizes and with a wide range of initial temperatures from at the fuel core. The radial temperature distribution is also studied in presence of the graphite coating. The graphite coating increased the heat flux from 6.61*10-6 W/m2 to 1.44*10-5 W/m2 at a 1900 degree centigrade inner core temperature, effectively doubling the heat flux without a graphite layer