Actual Problems of VVER SG Tubing Service Life Management

Reliable operation of steam generator heat exchanging tubes is the major problem for NPPs of different types. The paper deals with current approaches to horizontal steam generator tubes inspection and plugging and the actual problems of service life management. The causes and laws of tubing corrosion degradation are considered using the information - analytical system. The results of SG prototype corrosion tests are presented. A possibility of corrosion degradation process management is demonstrated. The experimental verification was made to prove the possibility of flaws initiation under standby modes. The methodology of the plugging criteria choosing and the proposals on their optimization are given. The studies are provided for pressure loading of the tubes with real flaws. The recommendations are given for improving of SG operation.