Non-destructive testing of a NPP's metallic equipment during operation

Some nondestructive testing methods and facilities currently used in the USSR and overseas to remotely control the quality of a NPPs metallic equipment during operation are reviewed. The ultrasonic and γ scanning devices designed to verify the integrity of nuclear reactor pressure vessels and piping weldments are considered. The acoustic emission techniques, ultrasonic holography and routine ultrasonic fault detection are acknowledged the most promising and safe when applied to reactor vessels. On the other hand, the radiographic methods are pointed out not to quarantee the identification of a flaw. There is also a description of a container designed to maintain and repair a nuclear reactor in the highly radioactive environment. The increased interest of foreign firms towards acoustic emission techniques is stressed