Effect of irradiation on some actinide and fission product ions' extraction using several tetraalkyl diglycolamides

Abstract

The radiolytic stability of different substituted diglycolamides such as N,N,N′,N′-tetrapentyl diglycolamides(TPDGA), N,N,N′,N′-tetrahexyl diglycolamide (THDGA), N,N,N′,N′-tetraoctyl diglycolamide (TODGA), N,N,N′,N′-tetradecyl diglycolamide (TDDGA) and N,N,N′,N′-tetra-2-ethyl hexyl diglycolamide (T2EHDGA) was investigated in solvent systems containing 30% iso-decanol as a phase modifier in n-dodecane kept in contact with a 3 M HNO₃ aqueous solution while irradiating in a gamma ray chamber up to 1000 kGy. The degradation of the solvent systems was qualitatively ascertained from measuring the distribution ratio values at 3 M and 0.2 M HNO₃ which gave a direct indication of the reusability of the solvent for long term reuse in separation processes such as `actinide partitioning'. The effect of irradiation on distribution values of Sr, Pu, U was also investigated with diglycolamide extractants both under extraction and stripping conditions. Stoichiometry of the extracted species was determined for Am(III) extraction using the fresh as well as the irradiated solvent systems involving all the five substituted diglycolamides at 3 M HNO₃ and the results indicated only marginal changes. GC-MS analysis was done for fresh and irradiated solvent systems of all the diglycolamides and attempts were made to identify the degradation products.