Preparation and dissolution of uranium dibutyl phosphate (U-DBP)

A sticky coating of Uranium Dibutyl Phosphate (U-DBP) was found to be formed on the surfaces of nuclear fuel reprocessing facilities and on the surfaces of reprocessed waste storage tanks. This poses both radiation exposure and criticality hazard. Hence, it is required to periodically dissolve U-DBP deposits. In this connection, an attempt was made to synthesis U-DBP from U₃O₈ and to evolve a suitable chemical formulation for its dissolution. The U-DBP complex synthesised was yellow coloured sticky deposit. For the dissolution studies, various formulations such as EDTA, disodium-EDTA and sodium carbonate were considered. From the literature it was seen that uranium deposits dissolve effectively in oxidising medium. Hence, dissolution studies were carried out in above formulations in the presence and absence of hydrogen peroxide, which is a well known oxidising agent. From the experimental results it was seen that of all the formulations used, sodium carbonate was found to be very efficient. In the presence of peroxide, the rate of dissolution was found to increase. Investigations were carried out to optimise the concentration of sodium carbonate, peroxide and also the temperature of dissolution. (author)