Oxidation studies of un-irradiated and irradiated Uranium Carbide targets for ISOL@MYRRHA

The growing interest in the production of nuclear radioisotopes for medical and industrial applications has led to the development of systems that exploit the interaction of nuclei with accelerated particles: ISOL (Isotope Separation On-Line) systems. It is within this framework that research is conducted at SCK CEN with the MYRRHA/MINERVA project. This project involves a 100 MeV proton linear accelerator (LINAC). The materials used for the targets will be UCx and ThCx Following irradiation, the targets will be considered nuclear waste; however, to meet safety criteria, due to their pyrophoric nature, they must be oxidized.
A safe and controlled oxidation process has been studied for six different samples (irradiated and non-irradiated) of UCx using XRD techniques, gamma spectrometry, and TGA-DTA-MS. Promising results have been obtained for the first time on irradiated samples, analyzing the differences and similarities of parameters characterizing the oxidation process: temperature, mass change, CO2 release, and heat production. It has been possible to demonstrate that studying non-irradiated targets is promising for obtaining results regarding irradiated materials as well. Furthermore, the potential release of gamma-emitting radioisotopes during the oxidation process has been analyzed: the spectra analyzed pre- and post-oxidation show no release.