Investigation of Corrosion of Zirconium alloy with Synchrotron X-ray Surface Analysis

Abstract

Evaluation of integrity and corrosion mechanism of primary circuit materials is one of the main factors to secure the safety of the nuclear power plants. Especially, zirconium alloys were widely used for fuel cladding materials for pressurized water reactors, and the research on the corrosion mechanism of zirconium alloys has been under active discussion after Fukushima accident. In this study, the dissolved hydrogen concentration, one of the conditions of primary water chemistry, was changed for investigating its effect on zirconium alloy corrosion. The corrosion experiment was conducted for 100 d, and the electronic structure of zirconium oxide was analyzed with using soft X-ray, and its characteristic differs from the distance from the oxide/metal interface. Also, with using X-ray reflectivity measurement method, the sub-Angstrom atomistic structure of single crystal yttria-stabilized zirconia/liquid interface was predicted, which is influenced by the temperature of hydration.