Recovery of uranium from primary radioactive liquid waste generated in uranium purification process

Uranyl nitrate raffinate (UNR) is generated in the purification step of UO2 production process which is a liquid effluent. Since this effluent contains residual uranium, its direct disposal is not permissible and hence it is first fixed in solid form as uranyl nitrate raffinate cake (UNRC) by suitable treatment method. Later this 'U' recovered at the Uranium mill. The filtrate from effluent treatment process contains sodium nitrate and other salts. This 'U' free filtrate is analysed for uranium and disposed off, for recovery of the valuable salts. The present process is manpower intensive, requires large storage space, and involves material handling work, transportation etc. In order to overcome these problems, the need for avoiding the generation of UNRC was felt. A new process resulting in avoidance of UNRC generation was studied in detail and demonstrated successfully at plant scale. The superiority of this process compared to the other options lies in the fact that no new reagents are required. The same solvents at the same concentrations are used, thus making the process more amenable for using on-line by dove-tailing into the existing set-up. The details of the process developed are presented in this paper. (author)