Diffusion of helium in the perfect and non perfect uranium dioxide crystals and their local structures

First-principles study of helium clustering at initial stage in ThO 2

“…We calculated the migration energy of He by the nudged elastic band (NEB) method. [38] The migration energy of He between two OISs is 3.80 eV, which is in agreement with the results reported by Da ¸rowski et al [39] Considering the environment with a high temperature in nuclear fuels, we suggest that He tends to be mobile in ThO 2 . In this work, we considered the clustering behavior of He atoms around an OIS with increasing concentration of He atoms.…”

“…[10][11][12][13] In recent years, a number of computational works concerned with the bulk and defect properties of nuclear fuels have been performed. [14][15][16][17][18][19][20][21] Zhang et al [14,15] investigated the mechanical and thermal properties of ThO 2 by first-principles calculations. Thompson et al [16] reported that the stability of noble gas atoms is related to the strain they caused in trap sites.…”

“…Yun et al [19] in-vestigated the clustering behavior of He in UO 2 , and found that He clusters affect the local mechanical properties of UO 2 . Dabrowski et al [20] reported that diffusion of helium between two octahedral sites in UO 2 is along a polyline rather than a straight line.…”