First-Principles Computational Research Of The Thermal Conductivity For ThC

For the community’s demand of energy, some countries have planned to improve and rebuild the nuclear engineering construction and fuel. Since the first generation of nuclear power plants was built in World War II, it has been four generations of nuclear power plants. Now Chinese governments vigorously develops fourth-generation nuclear power plant. Because of molten salt reactor’s good cycle reaction, people pay more and more attention on it. Thorium-based molten salt reactor (TMSR) has many advantages, such as high conversion efficiency, less radioactive nuclides, preventing nuclear proliferation. And the advantage of abundant thorium reserves, China has listed thorium-based molten salt reactor as a key projects in nuclear engineering. And it is also one of the advanced nuclear fission energy strategic leading science and technology projects in the future.Recent years, scientists focus on the nuclear material. Development of thorium-based fuels is the trend. The number of Th in the periodic table is90. Pure thorium’ melting and boiling point is very high. Its alpha phase is face center cubic structure (fcc). When its temperature reaches1400℃, The material happened phase transition and the phase is bcc. It is silver metal and it will be grey in the air. The structure of Thorium is fee at normal temperature and pressure (NPT). Its thermal conductivity is also very good. Nowadays people use of thorium-based fuel of ThO2as well ThO2-based oxides, but there are some difficulties, such as their high melting point, hardness to dissolve in liquid. These increase the difficult of follow-up work。 So scientists try to find better nuclear materials. the melting point of the metal ThC is high, the thermal conductivity is better, the thermal stability is also good. But people hasn’t do research on the thermal conductivity of thorium monocarbide, while the performance of the thermal conductivity is the extremely important nature in nuclear engineering. We study and calculate the thermal conductivity of insulator and conductor from the first principle. We calculate the thermal conductivity of ThC. For conductor, it includes the lattice thermal conductivity and electric thermal conductivity. The thermal conductivity of ThC is increasing with the increasing temperature. With the temperature increasing, lattice thermal conductivity is reducing, the electric thermal conductivity is increasing. And the percent of electric thermal conductivity is growing.