Radiation resistance and durability against thermal regeneration cycles of Ag-ETS-10 and Ag-ZSM-5 for collecting radioxenon

Abstract

Efficient porous adsorbents are crucial for: the mitigation of radioxenon emissions from nuclear installations, the production of Xe and the detection of clandestine nuclear weapon tests. Silver-exchanged zeolites or alike, specifically Ag-ZSM-5 and Ag-ETS-10, are promising candidates for these applications. However, knowledge on their radiation resistance is lacking and further research is necessary on their durability against thermal regeneration cycles. The radiation resistance was investigated for the first time by in situ irradiation with 133Xe up to about 100 MGy on Ag-ETS-10 and Ag-ZSM-5. In parallel, the durability of non-irradiated samples against at least 43 thermal regeneration cycles was investigated on both adsorbents. Fresh, irradiated and thermally regenerated samples were analyzed using different characterization techniques. The characterizations, and more specifically Xe adsorption at 296 K, did not show particular alterations due to the irradiation and thermal regeneration cycles. This is a major step forward for more efficient radioxenon trapping as it proves that both adsorbents can be used up to these irradiation levels and withstand 43 thermal regeneration cycles without any significant loss of Xe adsorption performance. Noteworthily, peak shifting and broadening were observed in the 29Si NMR signals of irradiated Ag-ETS-10 due to the paramagnetic 133Cs decay product.