A Model for Effective Thermal Conductivity of Unrestructured Sphere-Pac Fuel

A two-dimensional finite difference method is presented to calculate the effective thermal conductivity of sphere-pac fuel in its initial configuration. This method employs an approach using progressive unit cells for the various size fractions of the fuel The effects of temperature and fill gas pressure are also incorporated into the calculation. Comparison between computed and experimental values indicates that the model agrees with measured data to within 20%.