For a number of reasons, over the past ten years, much interest has been shown in developing the concept of advanced fuel in liquid-metal fast breeder reactors alongside the classical oxide fuel rod. To describe those concepts theoretically, the integral fuel rod code URANUS was extended to include a carbide fuel version. All the relevant material properties— thermal, mechanical, and irradiation-induced—for UC and (U,Pu)C were taken into account. Material data were extracted from published literature and after careful comparison were assessed and correlated. The models for solid body and gas bubble swelling and for fission gas release are newly developed and calibrated to accessible data. Together with the standard routines of URANUS for calculating temperatures, geometry in hot state, stresses, strains, crack mechanics, plasticity, gap conductance and burnup, and with the axial coupling of individual sections, a detailed description is available for precalculation and interpretation of carbide rod experiments.