Investigation of production conditions of ThO2–UO3 microspheres via the sol–gel process for pellet type fuels

Droplet Micro‐Reactor for Internal Gelation to Fabricate ZrO2 Ceramic Microspheres

“…ZrO 2 microspheres are typically fabricated by an internal gelation process to achieve the good sphericity, uniform size, and homogeneous structure . The sphericity of zirconium dioxide microspheres was typically defined as the ratio of the maximum diameter (circumscribed circle) to the minimum diameter (inscribed circle) of the microspheres and the sphericity should be controlled in the range of 1–1.2 . Meanwhile, the standard deviation of the size distribution should be controlled within 10% of the diameter of the ZrO 2 microspheres.…”

“…Meanwhile, the standard deviation of the size distribution should be controlled within 10% of the diameter of the ZrO 2 microspheres. In the application of fissile fuel particles, the UO 2 kernel product with a good sphericity can eliminate weak spots in the coated layers, which contain gaseous fission products, and certify irradiation performance during the reactor operation . To realize the internal gelation, the sol of ZrO 2 and the reagent of hexamethylenetetramine (C 6 H 12 N 4 ) are mixed, and the premixed sol solution needs to be stored at a low temperature (3°C) to prevent the gelation before it is used to generate sol .…”

Fabrication of dense (Th,U)O2 pellets through microspheres impregnation technique

“…The sol-gel microsphere pelletization (SGMP) technique, which employs free flowing and dust free microspheres as feed material for fabrication of the pellets, offers an alternative option. Several investigations have been made with the aim to develop the gel pelletization technique for the preparation of ThO 2 and (Th,U)O 2 pellets [1][2][3][4][5]. As the second option for reducing the time of fuel fabrication, a few alternatives such as the coated agglomerate pelletization (CAP) [6] and the particle/pellet impregnation [7,8] methods have been considered.…”

Sorption studies of cesium on TiO2–SiO2 mixed gel spheres

“…In the present study, a simple method using a gelation column designed in our previous work [13], containing two phases (methyl isobutyl ketone and ammonia) as sphere forming and gelling medium, allowing to direct preparation of TiO 2 -SiO 2 mixed gel spheres suitable for column operation, was developed. The adsorption behavior of mixed gel towards cesium was investigated.…”