Effect of gamma irradiation on MnO₂/Ag₂O hydrogen getter

Highlights: • MnO₂/Ag₂O hydrogen has been irradiated under gamma radiation until 4 MGy. • Phase quantification with PDF analysis shows that ramsdellite and pyrolusite are unchanged under gamma irradiation at 4 MGy With organic technological wastes, the efficiency of H₂ getter trapping was over 80% at 1.5 MGy • After gamma irradiation at 4 MGy, MnO₂/Ag₂O getter keeps its reactivity under hydrogen. • In presence of various organic technological wastes, the efficiency of hydrogen getter trapping under a close environment was over 80% under a total absorbed dose at 1.5 MGy. - Abstract: This study aims to show the stability of γ-MnO₂/Ag₂O hydrogen getter under gamma irradiation in order to be suitable for decreasing the hydrogen risk during the nuclear waste transportation. The chemical and the structural properties of the getter were barely unchanged for irradiated doses up to 4 MGy. The pair distribution function (PDF) analysis showed that the γ-MnO₂, which can be describe as an intergrowth of the ramsdellite phase (R-MnO₂) and the pyrolusite phase (β-MnO₂), had the same intergrowth rate (around 60% for β-MnO₂ and 40% for R-MnO₂) after irradiation and the silver containing promoter was also unchanged. The getter remains therefore efficient for hydrogen trapping. Furthermore, γ-MnO₂/Ag₂O was tested in a closed environment in the presence of hydrogen released by organic technological waste radiolysis, such as polyvinyl chloride, ion exchange resins, polyethylene and silicone. Over 80% of the hydrogen, generated by organic radiolysis, was trapped under a 1.5 MGy gamma irradiation