Development of advanced research reactor fuels using centrifugal atomization technology

Abstract

Rotating disk centrifugal atomization technology has been utilized to fabricate uranium silicide (U3Si, U3Si2) and U-Mo nuclear fuel powders having high uranium content per unit volume for high performance research reactor fuels. Atomized nuclear fuel powders have characteristics of a spherical shape with narrow size distribution, small specific surface area and high purity. The heat treatment time for the formation of U3Si by a peritectoid reaction was reduced from about 72 hours for comminuted powders to about 6 hours for atomized powders due to more rapid solidification of atomized powder with a finer microstructure. The homogeneity of fuel particles in fuel meats was improved by mixing atomized fuel powders with A1 powders using a V-shaped tumbler mixer. The atomized powders with a spherical shape and smooth surface were extruded under lower force than the comminuted powders with angular rough surfaces. The dispersed fuel meat with atomized powders resulted in an increased fuel powder loading density and higher thermal conductivity in the heat flow direction. The thermal swelling of dispersed fuel meat decreased due to the reduced specific surface area of spherical atomized nuclear powder. The atomized U-10wt.%Mo dispersion fuel showed less bubble formation than the comminuted fuel after an irradiation test with 40% bumup.

Effect of processing factors on the characteristics of centrifugal casting

“…The nano-wire is formed inside anodic aluminium oxide (AAO) templates. The method is also adopted for the development of reactor fuels [29][30][31], production of steel lined composite tubes [32,33], centrifugal slip casting of zirconia [34], etc. The list is unending and covers a vast range of products establishing the importance and versatility of the process in manufacturing technology.…”