Thermal conductivity modeling of the interaction layer of the irradiated U-Mo dispersion fuel

The fuel meat is composed of U-Mo fuel particles dispersed in an Al matrix. One of the limitations of the U-Mo dispersion type fuel is the formation of an interaction layer (IL) due to the interaction between the U-Mo fuel particles and the Al matrix. The formation of the IL results in the degradation of the properties of the U-Mo dispersion type fuel due to the consumption of the high thermal conductivity Al matrix and the amorphous nature of the IL. However, due to the small thickness of IL, the direct measurement of the IL thermal conductivity is difficult. Therefore, the objective of this study is the determination of the IL thermal conductivity from the experimentally measured fuel meat thermal conductivity using the analytical modeling and the finite element method (FEM) simulation. For the case of the high fission density fuel meat segment which was composed of U-Mo fuel particles disperse in the IL without overlapping between the dispersed particles, most of the analytical models prediction of the IL thermal conductivity values were close to the FEM prediction except the Maaxwell model because Maxwell model was developed for a low volume fraction of the dispersed particles whereas the U-Mo fuel particles volume fraction for the TK segment was around 50 %. Future work will focus about developing a correlation for the IL thermal conductivity as function of the fission density.