Mechanisms of Zr surface corrosion determined via molecular dynamics simulations with charge-optimized many-body (COMB) potentials

• An interatomic potential for zirconium–zirconium oxide–zirconium hydride is presented.
• Diffusion of oxygen and hydrogen into Zr (0 0 0 1).
• Deposition of O2 and H2O on low-index Zr surfaces.
• Surface structure affects resulting corrosion behavior.

A charge-optimized many-body (COMB) potential is proposed for the zirconium–zirconium oxide–zirconium hydride system. This potential is developed to describe the energetics of the interactions of oxygen and hydrogen with zirconium metal. We perform classical molecular dynamics simulations showing the initial corrosion behavior of three low-index zirconium surfaces via the deposition of O2 and H2O molecules. The basal (0 0 0 1) surface shows greater resistance to oxygen diffusion than the prism (101¯0) and (112¯0) surfaces. We suggest ways in which the surface structure has a unique role in the experimentally observed enhanced corrosion of the prism surfaces.