Characterization of uranium neodymium oxide microspheres synthesized by internal gelation

In the context of advanced nuclear fuel cycles including partitioning and transmutation (P&T), actinideco-conversion processes play an important role to close the loop. Therefore, actinides are embedded inceramics to be used as precursors for the fabrication of fuels. The solegel route by internal gelation is asuitable and dust-free conversion method. Furthermore, the required spherical particles are alreadyformed at the gel stage.Pure UO2 microspheres and U/Nd oxide particles with a variable content of Nd (5e40%) were fabricatedby internal gelation. Acid deficient uranyl nitrate and Nd nitrate solutions were used as precursorfor the microsphere fabrication. Neodymium is used as a surrogate for trivalent actinides, such asamericium. Mass- and diameter-distributions were studied and particle densities were calculated.Finally, the microspheres were thermally treated in a reducing H2:Ar gas atmosphere at 1573 K.The solid solutions of UO2 and Nd2O3 were investigated by scanning electron microscopy and X-raypowder diffraction. The obtained reflexes are indicating one cubic phase. Lattice parameter calculationswere performed, the results depend linear on the Nd content up to z 30%. Particle compositions containingmore Nd are showing an unexpected behavior