Guanze He¹, Junliang Liu¹, Anne Callow¹, Jing Hu², Mir Anamul Haq³, Sergio Lozano-Perez¹, Chris Grovenor¹; ¹Department of Materials. University of Oxford, ²Argonne National Laboratory , ³University of Huddersfield

Zirconium alloys have been widely used as cladding materials in Water Cooled Reactors and one of the major degradation mechanisms is the water facing corrosion enhanced by neutron radiation. Among various types of zirconium alloys, β-phase containing Zr-Nb alloys have shown a relative good resistance to this radiation-enhanced corrosion, which is relative to the damage behaviour of β-Zr and β-Nb phases embedded in the metal Zr matrix under radiation. We have conducted a series experiments to study the damage of the β phases under radiation. These include using TEM in-situ heavy ion irradiation and Energy Dispersive X-Ray Spectroscopy (EDX) to study the damage mechanisms of β-Nb particles, and using Electron Energy Loss Spectroscopy (EELS) and Atom Probe Tomography (APT) to study the damage of β-Zr phase under neutron irradiation. We have shown the micro-chemical and micro-structural changes can be a beneficial factor to the in-core corrosion of the Zr-Nb alloys.