Investigation of the microstructure influence in the thermo-physical properties of U-Mo alloys through the laser flash method

The U-Mo alloys are the most investigated and promising nuclear fuel material to be used in research and test reactors, according to the premises of the RERTR program, whose objective is to minimize the threats of nuclear weapons proliferation through the conversion of the nuclear fuels of research and test reactors form a high enrichment grade, HEU (235U>90%, to a low enrichment grade, LEU (235U<20%). The high density of the U-Mo alloys associated with its ability to keep the gamma phase metastable at room temperature are the main advantages of these alloys, with Mo contents of 5, 7 and 10 wt% were induction melted and ageing heat treated at 300 and 500 deg C for 72, 120 and 240 h. Microstructural characterization was carried out in the as-cast and aged conditions through XRD and OM techniques. The laser Flash Method at environmental temperature was employed to investigate the variation of the thermal diffusivity as a function of the microstructure obtained in the as-cast and aged conditions. (author)