This study presents a molecular dynamics analysis focusing on the behavior of interstitial helium (He) clusters in nickel (Ni), examining their formation, stability, and migration energetics. We found that the binding energies of interstitial He within a He cluster are positive and increase with the cluster size, indicating a preference for He atoms to cluster together. However, our findings also reveal that while the formation energy increases monotonically with cluster size, the increase in binding energy is non-monotonic. Importantly, small He clusters were found to be thermally unstable at reactor operational temperatures (approximately 600 K), with the He2 cluster exhibiting instability even at room temperature. With a binding energy of 0.44 eV for a He4 cluster, we hypothesize that for He bubbles to form via homogeneous nucleation (i.e., through trap mutation) at reactor operating temperatures, the He concentration must be high enough to facilitate the formation of He clusters of at least size 4 or larger. At finite temperatures, He clusters of size 7 and larger trap mutate immediately. However, cluster sizes 10 and larger will trap mutate even at 0 K. As expected, interstitial He and small He clusters are highly mobile. This mobility was observed not only at room temperature, but also at temperatures as low as approximately 200 K. Furthermore, the mean squared displacement method has been utilized to determine the migration barriers and the corresponding prefactors for clusters ranging from He1 to.He6