LAUSR

Abstract We present an approach to calculate the bias factor in polycrystalline anisotropic systems such as zirconium. A method defining the interaction between point defects and cylindrical sinks is generalized to include elliptical prismatic dislocation loops. Using the correlation between the internal sink strength and boundary sink strength, and statistical information from electron backscatter diffraction (EBSD), we determine the bias factor under four scenarios: equiaxed, elongated, random and textured polycrystals. The model indicates that the average sink strength in a polycrystal is equivalent to the sink strength of a grain of average size and average crystal orientation. This method can be applied to a number of irradiation growth mean field rate theory models in unstressed polycrystals, that are based on diffusional anisotropy differences (DAD), cluster dynamics, or a combination of cluster dynamics and one dimensional fast diffusing interstitial clusters.