Development of a High Density Uranium Nitride-Uranium Silicide Composite Accident Tolerant Fuel

摘要

Uranium dioxide (UO_2) has been used for nuclear power generation primarily due to its high melting point. Other beneficial properties include thermal stability, and low swelling under irradiation. This comes at the expense of a relatively low thermal conductivity of 7-8 W/m·K, which becomes lower with increased temperature and burn-up. A fuel with a higher thermal conductivity will increase the efficiency of heat removal, thus lowering centerline temperatures and reducing hot spots. In an accident scenario these qualities become more important. Higher thermal conducitivity can significantly improve safety margins by reducing the amount of stored energy in the fuel while lowering temperatures overall.