Understanding the mechanisms of helium-induced damage in zirconium alloys used in nuclear reactors is essential for ensuring both reactor safety and the longevity of materials. However, atomistic simulation of helium (He) in $\alpha$ -zirconium ( $\alpha$ -Zr) has proven to be challenging due to the limitations of conventional empirical potentials. In this study, we developed a deep-potential (DP) model to explore the diffusion and nucleation behavior of He in $\alpha$ -Zr through molecular dynamics simulations. The DP model demonstrates strong consistency with density functional theory (DFT) results in predicting elastic constants, phonon spectra, and thermodynamic properties, significantly outperforming traditional empirical potentials. We found that helium atoms preferentially occupy the basal octahedral (BO) and tetrahedral (T) interstitial sites in $\alpha$ -Zr, with a diffusion activation energy of 0.34 eV. Increased concentrations of He in $\alpha$ -Zr lead to lattice distortions, which degrade the material's mechanical properties. The process of He bubble aggregation shows characteristics of dynamic equilibrium, and the size of the He clusters in $\alpha$ -Zr is positively correlated with temperature.

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• Interatomic & molecular potentials
• Intercalation
• Deep learning
• Molecular dynamics