An integrated modeling and experimental approach to study hydrogen pickup mechanism in zirconium alloys

摘要

Hydrogen pick-up during corrosion of nuclear fuel cladding is a critical life-limiting degradation mechanism in Light Water Reactors. In this study, the oxidation kinetics and hydrogen pickup of a Zr-0.5Nb and an annealed Zr-1.0Nb alloys are being measured during corrosion in pure water autoclave (360 C, 18 MPa). Both the oxidation and hydriding kinetics are successfully reproduced by the Coupled Current Charge Compensation (C4) corrosion model, which now includes proton transport. The nanoscale porosity in the oxides are measured quantitatively by TEM. It is shown that a higher oxide porosity corresponds to a higher proton diffusivity predicted by the C4 model.