Zirconium (Zr) alloys have been widely used as structural materials for in-core components in water-cooled nuclear reactors. During normal operation, these materials are exposed to a neutron flux in the core of the reactor, resulting in material degradation such as irradiation-induced anisotropic growth, thus affecting their performance in the long-term. Experimental and theoretical studies have shown that irradiation-induced defects in zirconium lead to the formation of defect clusters and loops. The anisotropy in the migration of defects has been suggested to play an important role in irradiation growth in pure Zr and its alloys. However, the mechanisms that govern the microstructural evolution that lead to the observed anisotropic growth of Zr is still unclear. In the present work, we perform a molecular dynamics simulation study of irradiation-induced lattice defects in Zr to investigate the formation of clusters and loops. Irradiation-induced damage is modeled by constrained stochastic formation of vacancies and self-interstitial atoms in bulk Zr. Using this approach, the formation and evolution of defect clusters and loops were determined. The dynamic properties of lattice defect structures were investigated through the evaluation of their migration and diffusivity. We found that the diffusivity of vacancy and interstitial clusters is anisotropic and slow, while the diffusivity of large loops is relatively high and confined to the $〈a〉$ plane.

锆（Zr）合金已广泛用作水冷核反应堆中堆芯组件的结构材料。在正常运行期间，这些材料在反应堆堆芯中暴露于中子通量，导致材料降解，例如辐射诱导的各向异性生长，从而长期影响其性能。实验和理论研究表明，锆中由辐照引起的缺陷会导致缺陷簇和环的形成。已提出缺陷迁移中的各向异性在纯Zr及其合金的辐照生长中起重要作用。但是，控制微观结构演变导致观察到的Zr各向异性生长的机制仍不清楚。在目前的工作中，我们对Zr中辐照引起的晶格缺陷进行了分子动力学模拟研究，以研究簇和环的形成。辐射诱导的损伤是通过大量Zr中空位和自填隙原子的随机形成来模拟的。使用这种方法，确定了缺陷簇和环的形成和演化。通过评估其迁移和扩散性，研究了晶格缺陷结构的动力学特性。我们发现空位簇和间隙簇的扩散率是各向异性且缓慢的，而大环的扩散率则相对较高并且被限制在 辐射诱导的损伤是通过大量Zr的空位和自填隙原子的随机形成来模拟的。使用这种方法，确定了缺陷簇和环的形成和演化。通过评估其迁移和扩散性，研究了晶格缺陷结构的动力学特性。我们发现空位簇和间隙簇的扩散率是各向异性且缓慢的，而大环的扩散率则相对较高，并局限于 辐射诱导的损伤是通过大量Zr中空位和自填隙原子的随机形成来模拟的。使用这种方法，确定了缺陷簇和环的形成和演化。通过评估其迁移和扩散性，研究了晶格缺陷结构的动力学特性。我们发现空位簇和间隙簇的扩散率是各向异性且缓慢的，而大环的扩散率则相对较高并且被限制在$〈\mathrm{一种}〉$ 飞机。