Pranay Kumar Sinha

Thermal decomposition studies of aqueous and nitric solutions of hydroxyurea

Hydroxyurea and its derivatives are important nonsalt forming reductants in partitioning of uranium and plutonium in the nuclear fuel reprocessing operations. There is no experimental data available in open literature describing pressurization due to the thermal decomposition of aqueous and nitric solutions of hydroxyurea at elevated temperatures. Authors studied thermal decomposition of hydroxyurea-nitric acid system and resultant pressurization at various concentrations of nitric acid in an adiabatic calorimeter in closed-vent conditions. During these experiments, pressurization was observed. In this paper, results of these experiments have been discussed.

Development of a urea-adduct process for recovery of n-alkane based diluent from spent PUREX/UREX solvent

Urea-adduct process is commercially used to selectively separate n-alkanes from industrial hydrocarbon mixtures. Authors have explored application of this method for recovery of n-alkane based diluents from spent PUREX/UREX solvent. Traditionally this separation is performed by vacuum distillation, an energy-intensive process. The proposed method is simple and does not involve either exotic chemicals or complex processing steps. Application of urea-adduct process for recovery of diluent from spent solvent is reported here possibly first time in literature. Physical properties such as densities, viscosities and vapour pressure for irradiated organic solutions were also measured and reported.

New data on decomposition of nitric solutions of acetohydroxamic acid

Acetohydroxamic acid (AHA) is an important complexant/reductant for Pu(IV) in the UREX process. It decomposes in the presence of nitric acid. In literature, its decomposition kinetics in nitric acid is traditionally reported as pseudo-first order reaction. In this study, new experimental data were reported for kinetics experiments under wide consecration conditions. It was found that the decomposition reaction was first order with respect to both the components hence overall second order.