In-service defects in the heat-exchange tubes of steam generators at nuclear power plants

We consider specific features of the in-service defects in the heat-exchange tubes of steam generators at nuclear power plants with VVÉR (water-moderated water-cooled power reactor) power-generating units. The existence of correlation between the character of defects and the mechanism of their formation under the operating conditions is established. It is shown that the process of formation of defects is connected both with the intercrystalline and intracrystalline mechanisms of cracking detected in different sections of the tubes.