Advanced external gelation for infiltrated uranium dioxide transmutation target fabrication

Nuclear energy is a low CO2 emission strategy for energy security and sustainable development. As such, spent nuclear fuel management in the framework of advance concepts of nuclear fuels is necessary. The long-term radiotoxicity and decay heat generation of spent fuel is dominated by minor actinides (Am, Np, Cm), for which partitioning and transmutation schemes are being investigated. A sol-gel route for the fabrication of uranium dioxides microspheres via internal gelation, followed by aqueous solution infiltration was recently reported for transmutation target applications [1]. In this study, we are revisiting the feasibility of fabricating hydrated gel microspheres using external gelation of uranium aqueous feeds. The experimental results indicate that the use of ammonia gas as a pre-hardener can be circumvented by
changing the feed conditions, which is beneficial in the further application of the external gelation process at laboratory scale.
Thermogravimetric analysis is applied to investigate the effect of drying and calcination of the hydrated gel microspheres.