ZHAO Xingyu, MA Jingtao, HAO Shaochang, DENG Changsheng
(State Key Laboratory of New Ceramics & Fine Processing, Collaborative Innovation Center of Advanced Nuclear Energy
Technology, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China)

Abstract: In this paper, external gelation process line established by INET (Institute of Nuclear and New Energy Technology，Tsinghua University) was introduced, which was used for the preparation of ammonium diuranate gel microspheres with 3 kg U each batch. The innovative integrated dissolving, cooking and dispersing equipment, AWD (aging, washing and drying) device and vibrating separator were introduced. And based on the key equipment, acid-deficient dissolution, precipitation problems in the boiling process, effects of nozzle diameter and AWD process on balling performance were studied. Finally, ammonium diuranate gel microspheres with qualified diameters were successfully produced using the newly developed scale-up equipment and process, and prepared for the rest of the dry process and the resulting qualified UO₂ kernels.

Key words: ammonium diuranate gel microspheres; large scale preparation; external gelation process