Progress in development of MOSART concept with Th support

A study is under progress to examine the feasibility of Molten Salt Actinide Recycler and Transmuter system with U-Th support (MOSART+Th) fuelled with different compositions of actinide tri-fluorides (AnF{sub 3}) from used LWR fuel. New fast-spectrum design options with homogeneous core and fuel salt with high enough solubility for AnF{sub 3} are being examined because of new goals. Experimental data base created was used for further development of MOSART+Th technology as applied to consumption of AnF{sub 3} while extracting their energy. The flexibility of single fluid MOSART+Th concept fuel cycle is underlined, particularly, possibility of its operation in self-sustainable mode (CR=1) using different loadings and make up. The paper summarizes the current status of the design data for the MOSART+Th concept received within ISTC 3749 Task. (authors)