PREPARATION OF DENSE UO_2 FUEL KERNELS BY EXTERNAL GELATION PROCESS (Ⅰ)

A technological process is proposed for the production of dense kernels forthe high-temperature reactor A concentrated uranyl nitrate aqueous solution withurea, ammonium nitrate, poly-vinylalchohol, ethylene glycol, tetrahydrofurfurylalcohol as additives is dispersed into uniform droplets which are hardened byexternal gelation. The process is very simple and consists of only a few steps.Since organic polymer is used as sticker, the wet microspheres is very stable.Four parameters: geometrical factor, phisical factor, critical flow and vibrationfrequency must be controlled.