Modelling of zirconium growth under irradiation and annealing conditions

•An Object Kinetic Monte Carlo model for Zr growth under irradiation is proposed.•Original microstructural features are reproduced by the model.•A large parametric study is performed to understand these microstructural features.• loop alignments are very sensitive to the flux.•During annealing, the defects can evolve in a non-monotonous way.