Recovery and Purification of Uranium from Rejected-Prototype Fuel Plates with Use Innovative Method

Abstract

In nuclear research reactor fuel producing factories, in order to recover uranium from aluminum plate scraps of oxide fuel, the dissolving process in the caustic soda and nitric acid and, ultimately, the solvent extraction process for the purification of uranium from the UNH are used. In this research, the results of separation and purification of uranium from scraps of aluminum oxide fuel plates are reported in a new and different method and without the solvent extraction process. In this method, the virtual plate fuel fragments containing U3O8 were dissolved in caustic soda solution. Then, the suspension obtained from dissolution of the aluminum sheath, together with particles of U3O8 was reacted with 40% HF solution. The product obtained was subjected to heat treatment to oxidize its U+4 by air oxygen. Next, the uranium in the product oxidized by the leaching process was leached and separated from the impurities and was precipitated in the form of the very pure compounds of AUC and ADU. These intermediaries were converted into pure U3O8 by calcination. The results of the analyzes show that U3O8 produced in this way have higher purity compared to U3O8 produced from pure UF6 as well as from U3O8 from defective actual oxide fuel plates which in scientific sources have been purified by the solvent extraction process from the UNH. At the same time, in this method two samples of pure U3O8 powder with grain size of 86% and 94% (above 45 microns) are also produced directly from ammonium bicarbonate leached solutions through formation of AUC sedimentation, the characteristics of which recommend the applicability of this method in terms of chemical purity and grain size of U3O8 produced for enriched uranium in a fuel plate manufacturing line.

Keywords

• aluminum plate scrap
• fuel plate
• thermal treatment
• leaching
• precipitation
• uranium