Strengthening of Zircaloy-4 with Oxide Particles by Surface Treatment using Laser Beam

Accident tolerant fuel (ATF) cladding is being developed globally after the Fukushima accident with the demands for the nuclear fuel having higher safety at normal operation conditions as well as even in a severe accident conditions. Korea Atomic Energy Research Institute (KAERI) is one of the leading organizations for developing ATF claddings. One concept is to form an oxidation-resistant layer on Zr cladding surface. The other is to increase high-temperature mechanical strength of Zr tube. High-power laser beam was exposed on the zirconium surface previously coated by oxides. Various oxides such as Y₂O₃, CeO₂, Gd₂O₃, Er₂O₃ were used for the ODS treatment. In this study, the effect of strengthening by the ODS treatment was investigated. The oxide particles of Y₂O₃ were dispersed well in the Zr matrix at the surface region.