Characterization of ThO2 and (Th,U)O2 pellets consolidated from NSD-sol gel derived nanoparticles

Sinterable ThO2 and mixed 70%ThO2-30%UO2 nanopowders were synthesized and calcined at a low temperature by surfactant assisted sol-gel process using three different nonionic structure directing (NSD) agents: TritonX100, Polysorbate 80 and Polysorbate 20. The produced powder samples, with high surface area and micro and meso pores, were pressed and sintered to form high density ThO2 and (Th,U)O-2 pellets. The calculated green and sintered densities of the fabricated pellets, and the results of their microstructural characteristics studies, utilizing SEM images, show that developed synthesizing method yields a satisfactory sinterability of the synthesized ThO2 and ThO2-UO2 nanopowders at low temperature. Also, the final grain size of the pellets reached less than a micrometer in size. The ThO2 and (Th,U)O-2 pellets fabricated by synthesized powder using Triton X100 had a higher density and better grain growth. The uranium presence in the mixed oxide pellets led to better sinterability and more normal grain growth.