Numerical Investagation of the Material Properties and Resistance Characteristics of Fuel Assemblies for Gas Cooled Reactor

The development of nuclear power contributes to the efficient utilization of energy, and the emergence of fourth-generation reactor is expected to further improve the efficiency and safety of nuclear energy utilization. In this work, the material properties for the fourth-generation reactor are studied. The coolant for fuel components, fuel cladding materials, and fuel pellet materials for the fourth-generation reactor considering its characteristics such as higher heat transfer capacity, better inherent safety and chemical compatibility between fuel cladding and coolant, are investigated and analyzed. Supercritical carbon dioxide is selected as the coolant, oxide dispersion strengthened(ODS)steel as the fuel cladding material, and UN as the fuel pellet material. The physical properties of selected materials are studied to confirm their feasibility with gas cooled reactors. Resistance performance of materials is also investigated. It is found that flow rate and temperature significantly affect friction coefficient, and that the friction coefficient gradually decreases as operating condition approaches criticality under the near-critical condition.