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To establish the use of TEHDGA/isodecylalcohol/n-dodecane solvent system for actinide partitioning from HLW, the hydrolytic and radiolytic stability of the solvent was investigated. Hydrolysis of TEHDGA with nitric acid at room temperature was not observed. Radiolytic degradation was observed and found to increase with increase in absorbed dose. It was found that the presence of n-dodecane enhances the degradation of TEHDGA whereas isodecyl alcohol, the phase modifier, has no such effect. At gamma-radiation dose as high as 0.2 MGy, no significant loss of TEHDGA was observed. The degradation products were identified by GC-MS, the main products were formed by cleavage of ether and amide bonds of TEHDGA molecule. The extraction behavior of Am(III) at 4.0 M HNO3 does not vary much with increase in absorbed dose, however stripping behavior is affected by the presence of acidic degradation products formed during radiolysis. The findings indicate that the solvent retains its expected extraction and stripping properties up to a high gamma-radiation dose of 0.2 MGy. Irradiated solvent was purified and made suitable for reuse by treating it with 5% w/v Na2CO3 solution, basic alumina and finally by distillation at reduced pressure.

A novel synthetic method for the preparation of different sorbent-polymer composite beads has been developed under simple laboratory conditions. Copper hexacyanoferrate was synthesized, and its composite beads of required size were synthesized by phase-inversion technique, using polyethersulfone as the polymer matrix. Suitable size and mechanical stability, along with their spherical shape, make these composite beads most appropriate for column operation. The efficiency of these composite beads was tested for the removal of cesium, using radioanalytical techniques, in batch conditions. The effect of pH, the initial metal ion concentration, and contact time was also investigated. The synthesized beads perform best in the pH range 5-9. Different sorption isotherm models were applied to the experimental data. Equilibrium data are represented well by the Langmuir isotherm equation, with a monolayer sorption capacity of 1.56 mg g À1 for the swollen beads. Kinetic modeling analysis, by fitting the data in the pseudo firstorder, pseudo second-order, and intraparticle diffusion equations, shows that the pseudo second-order equation is the most appropriate model for the description of sorption of cesium ions onto the composite beads. The process mechanism is found to be complex, consisting of both intraparticle diffusion and film diffusion.

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High cesium (Cs)‐bearing sodium borosilicate glasses incorporated with varying concentrations of TiO2 up to 10 mol% at the expense of B2O3 were prepared by the conventional melt quenching method. Physicochemical properties of the glasses studied include Cs volatilization losses, leaching, and glass transition temperatures. Structural aspects of the glasses were investigated using Fourier transform infrared, 11B MAS NMR, and UV‐visible optical absorption techniques. From the detailed investigations on these glasses, optimum concentration of TiO2 for minimum volatilization losses of Cs has been established. Structural studies revealed the role of TiO2 in the Cs volatilization as well as leaching characteristics of the glass. Based on our studies, it can be inferred that the glass sample with 5 mol% TiO2 content gives the optimum formulation with regard to the leaching and Cs volatilization losses. Results of the study are useful in the development of high Cs‐bearing glasses for their use as a gamma source for radiation technology application.