Program for Steam Generator Tubing Reliability Tests in Japan

Abstract

This paper describes a 5 year Japanese program to assess the reliability of steam generator tubing. Steam generator tubing has suffered from degradation caused by intergranular attack (IGA) at the tube support plate crevice and just below the top of the tube sheet since 1981. Various counter measures dealing with environment, material, structure, etc. have been employed to cope with this problem and which have resulted in a reduction of IGA. The testing aimed at verifying the effectiveness of these countermeasures and of the tubing reliability is described.