A set of calculations has been carried out with the EUGES-ARIES code system to study the swelling performance limits of a sodium-bonded mixed-carbide pin design, which was recently proposed for the introduction of advanced fuels into liquid-metal fast breeder reactors. The results indicate that a useful peak burnup of 150000 MWd/ton can be attained with pin diametral plastic deformations up to 2%, under optimal irradiation conditions. However, probable thermal disturbances in the fuel and cladding mechanical deterioration due to steel carburization still represent a risk source for pin failure. A further improvement of the swelling performance of mixed carbides is therefore needed to refine the examined pin design for future full-scale reactor applications.