Thermodynamic properties of uranium were studied in (U + Ga), (U + Sn) and (U + Ga + Sn) systems. Activity and activity coefficients of uranium were determined in alloys with tin and (gallium + tin) eutectic (0.135 Sn mass fraction) between T = (573 and 1073) K. Solubility of uranium in (Ga + Sn) eutectic and in pure Ga was measured between T = (298 and 1073)K. Activity coefficients, partial and excess thermodynamic functions of uranium in alloys with Ga, Sn and (Ga + Sn) eutectic were calculated. (C) 2015 Elsevier Ltd. All rights reserved.