The comparable structural, elastic anisotropic and thermophysical properties of advanced U–Si fuel to baseline UO2: a DTF method

Based on a few assumptions regarding crystal construction, the structural, elastic anisotropic and thermophysical properties of advanced U–Si system and baseline UO2 have been investigated through a first-principles density functional theory (DFT) method. The calculated lattice constants are in good agreement with the previous experimental and theoretical values. The elastic properties, including bulk modulus, shear modulus, Young’s modulus, Pugh’s B/G ratio, Poisson’s ratio and elastic anisotropy are derived from the elastic data $${C}_{ij}$$ C ij . The calculation results show that the U3Si2 and β-U3Si materials are brittle, while single-crystal UO2 is ductile. Based on Poisson’s ratio, the advanced U–Si compounds and the baseline UO2 compound will have the different elastic deformations. Moreover, the U3Si2 and β-U3Si have elastic anisotropy behavior, while the UO2 with an elastic isotropic characteristic mainly. Finally, Debye temperature, melting point, Voight harness and the hoop stress are predicted through different empirical formulas. The hoop stress of UO2 is larger than that for U3Si2 and β-U3Si. There will be highlight implications of these calculated data for future U–Si fuel pellets’ design and preparation. Graphical abstract