Hydrogen trapping properties of Zr-based intermetallic compounds in the presence of CO contaminant gas

Abstract

Intermetallic compounds, as hydrogen getters, are considered to control the quantity of hydrogen generated in radioactive waste packaging. The compounds ZrCo, Zr 2Fe and a Zr-rich Zr–Ti–V alloy have been chosen as they form very stable hydrides at ambient temperature. However, other gases are produced in the packaging such as carbon monoxide, a gas known to poison the surface of intermetallic compounds and to hinder the hydrogen sorption reaction. The three Zr-based compounds have been first characterized regarding their metallurgical state and their gas sorption properties toward pure hydrogen. Then, the sorption properties of the activated materials have been studied using a mixture of 5 vol.% CO + 95 vol.% H 2. We demonstrated that though the presence of CO sharply slows down the reaction rate the activated compounds still show significant sorption properties. Therefore, the presence of contaminant gases is not detrimental for the target application.