Isotopic Water Handling and Hydrogen Isotope Recovery for Fusion Application by Using the Zr(V_0.5Fe_0.5)₂ Alloy—I: Sorption and Role of Hydrogen and Oxygen in the Batch Conversion Method

Experimental investigation of the reaction of light and heavy water vapors with a metallic alloy and the release of hydrogen by batch-mode conversion with a Zr(V_0.5Fe_0.5)₂ getter is presented. The dependence of cracking of water vapor on the alloy temperature and water vapor pressure is studied. The roles of initial as well as increasing concentrations of hydrogen and oxygen in the alloy are delineated. The conversion rate constant is observed to shift from being surface dissociation process-dependent to bulk diffusion process-dominated during the conversion process. Hydrogen sorption in the alloy and its release during the batch conversion of water vapor, which assumes considerable significance from the perspective of recovering tritium as fuel gas from tritiated water waste, are discussed based on the studies performed that maintained the getter at various temperatures in the range of 100 to 400°C and over a water vapor pressure range of 50 to 500 Pa, with various hydrogen and oxygen concentrations in the getter alloy.