Partitioning processes for minor actinides: influence of gamma radiation on extraction systems based on diglycolamides

For advance nuclear fuel cycles, different approaches based on extraction processes are being developed for minor actinides recycling contained in high level radioactive waste. To predict the behaviour along the extraction process is one of the most important challenges in defining the process development and safety. Solvents used for the partitioning will be in contact with highly radioactive aqueous solutions containing elevated nitric acid concentrations, therefore, it must be identify any unexpected behaviour as well as maximize the regeneration of the spent solvent. Malonamides and diglycolamides are considered as the extractants with higher possibilities to be used at large-scale in Europe. This work describe the physic-chemical effects of gamma radiation on solvent systems based on TODGA (N,N,N´,N´-tetraoctyl diglycolamide) such us the DIAMEX, i-SANEX and GANEX processes. The behaviour of the extraction systems under radiation, by using a homogeneous gamma flux of external 60Co sources, has been explored depending on the structural stability of ligand, the nature of the diluents or the presence of different ions, etc,. A systematic characterization of degraded samples (composition and extraction properties) and the study of their interferences with other phases are being carried out.