Thermophysical and thermochemical evaluation of prospective Th-fuels for advanced reactors

In this talk we first summarize the developments completed in the context of AHWR fuels. We then discuss the rationale towards the timely development of innovative metallic fuel systems and present our recent results on thorium-uranium alloys (Th-10 wt.% U, Th-20 wt.% U). Basic R and D studies, required in the future for developing these thorium-based metallic fuel systems, will also be highlighted. Performance evaluation of nuclear fuels needs their reliable data on thermophysical and thermochemical properties in virgin states as well as in high burn up states wherein the fission products largely accumulate. Thermal and chemical transport properties of the fuel markedly differ in different type of fuel matrices that are being considered on the merits of achieving high burn up, ease of fuel handling, fabrication, reprocessing, and waste management. In our effort of harnessing nuclear power through thorium utilization, the prospective Th-fuels for the future reactors will be as oxide and metallic matrices and also as molten salt in the successive generations. With the past experience of working with uranium based fuels, the essential properties that help simulating the performance of the new fuels are under the purview of our present investigations. Results obtained thus far in the cases of thoria based fuels, metallic fuels and molten salt compositions will be summarized in this presentation