Use of Ultrasound in Obtaining Uranium Oxides

BOERO, NORMA; SASSONE, ARIEL; MÉNDEZ DE LEO, LUCILA P.; NOVARA, OSCAR

Orlando, Florida, USA

Congreso; Meeting of the American Nuclear Society; 1997

American Nuclear Society

U3O8 is used in the manufacturing of material test reactor plate nuclear fuel. UF6(g) is hydrolyzed to obtain uranyl fluoride, which is then precipitated with ammonium hydroxide to obtain ammonium diuranate (ADU). ADU is afterwards calcinated at 800 ºC to U3O8 and then mechanically and thermally treated to obtain a powder that meets the needed specifications. Ultrasound has been applied in the precipitation stage of ADU in order to improve the characteristics of this precipitate. Considerable changes in the characteristics of the ADU agglomerates were found when ultrasound was applied during precipitation and for at least 30 minutes afterwards. The filtration rate of the powder turned faster and it was easier to dry.  X-rays showed that U3O8 obtained from treated ADU, by calcination at 800 ºC, matched better the reference structure than untreated powders. For these powders, hard mechanical treatment could be avoided in the preparation of final U3O8. The resulting powder showed adequate characteristics.