Development Of High Density Uranium Compounds And Alloys As Dispersion Fuel For Research And Test Reactors

Most of the research and test reactors worldwide have undergone core conversion from high enriched uranium base fuel to low enriched uranium base fuel under the Reduced Enrichment for Research and Test Reactor (RERTR) programme, which was launched in the late 70's to reduce the threat of nuclear proliferation. Various compounds of uranium were considered and studied for the purpose but the best fuel compound identified for the development of low enriched uranium base fuel was uranium silicide (U(3)Si(2)). The fabrication method qualified for making U(3)Si(2)-Al dispersion fuel was giving a maximum heavy atom density in the range of 4.8 g/cm(3) to 6.0 g/cm(3). Under the RERTR programme an ambitious goal of achieving heavy metal density of 8.0 to 9.0 g/cm(3) in aluminium based dispersion fuel was set and to realize this high density gamma - stabilized uranium alloy (e.g. U-Mo, U-Zr etc.) powder in conjunction with advanced fabrication techniques. At Metallic Fuels Division of BARC, R&D efforts are on to develop these high density uranium alloys/compounds. The paper describes the dispersion fuel development break through, which has been made towards the development of U(3)S(i)2-Al dispersion fuel for the modified core of APSARA reactor. The paper also includes the development of Uranium molybdenum alloys for getting higher heavy metal density for dispersion fuels. The synthesized product was then characterized by XRD for phase determination. The photomicrographs of different alloys/compounds prepared are also included in the paper.