Non-destructive examination of welds in small diameter pipes in the nuclear industry

Publisher Summary In the nuclear industry, there are many components that require stringent and reliable non-destructive examination. Traditionally, inspection of welds for the detection of body defects has been done either by ultrasonics or radiography and there has been much debate over the years as to the relative merits of each technique. Some defects are more readily detectable by ultrasonics and others by radiography. Techniques in both these areas are continually improving and making inspection more reliable. Within the author's company, both these approaches are extensively used to examine large numbers of tubular butt welds in steam generator plant. Ultrasonic inspection has been carried out using assisted hand scanning as well as, more recently, automatic inspection equipment, which has the benefits of producing permanent records of the inspection as well as improved repeatability. Ultrasonic inspection of austenitic materials previously caused many problems, but these have now largely been overcome using modern techniques, and austenitic welds are now routinely inspected.