Models have been developed to describe secondary hydriding phenomena. Thermodynamic models for the Zr–H and Zr–O–H systems provide the terminal solubility of dissolved hydrogen and oxygen in the α-Zr phase as a function of temperature and partial pressure. A simulation of the Sawatzky and Vogt experiment, based on a finite-element kinetic model with the thermodynamic predictions as a boundary condition, is further developed to describe the redistribution of hydrogen in a Zircaloy-2 sample placed in a temperature gradient. This analysis confirms the hydrogen diffusion coefficient.