The effect of the point defects on the behavior of a crack inside of a pressure tube

The effect of the vacancies and interstitials created by irradiation on the macroscopic behavior of a crack in an in-service pressure tube is analyzed in the present work. The isolated crack is considered as a sink of point defects. The vacancy and interstitial total flows to the crack tip and crack surfaces are calculated from the corresponding values of the so-called fictitious sink strengths of the crack tip (k2fT) and crack surfaces (k2fS) and from the average defect diffusivity values and the average defect concentrations. From the interatomic potential which were used to describe the material, it is predicted that the crack length and the opening of the crack surfaces will be increased by the irradiation.