Hydrolysis and radiation stability of the ALINA solvent for actinide(III)/lanthanide(III) separation during the partitioning of minor actinides

In the present study, the hydrolytic and radiolytic degradation of chlorine-substituted aromatic dithiophosphinic acids, which are used in the ALINA process for actinide(III)/lanthanide(III) separation was investigated. With the aid of GC-MS, the most important degradation products in the organic phase after hydrolysis with HNO3 and gamma-irradiation were identified. A quantitative determination of the course of the degradation in long-term hydrolysis experiments with 0.5-3.0 mol/L HNO3, HCl, H2SO4 was performed using GC/FID. Irradiation experiments were carried out up to an absorbed total dose of 2.0 MGy, also in the presence of 0.5 mol/L HNO3. The extraction behaviour for An(III)/Ln(III) separation was studied after hydrolysis and radiolysis. The results show that the degradation products formed by oxidation have no significant influence on extraction.