Effect of oxidation conditions on chlorination reaction of Zircaloy-4 hulls

Abstract

The effect of oxidation conditions on the chlorination reaction behavior was investigated by using Zircaloy-4 (Zry-4) hulls oxidized at various conditions. When the hulls were oxidized at 500, 600, and 700°C for 5h, decrease of reactant mass after the chlorination reaction at 380°C for 3h was 41.6, 26.0, and 0.0wt.%, respectively, while that of fresh Zry-4 hulls was 54.1wt.%. Surface analysis results revealed that the oxidation state of Zr is significantly dependent on the oxidation temperature. The effect of oxidation time was also investigated for the Zry-4 hulls oxidized at 500 and 700°C up to 24h. Based on the experimental results, it was concluded that the chlorination method is applicable to the Zry-4 hulls oxidized at 500°C without removal of the surface oxide layers, while a pretreatment is required to recover Zr from the hulls oxidized at 700°C.