HSE has investigated a number of instances where the NDT has been falsified, mainly at the fabrication stage. Welds have not been thoroughly tested and/or the results have been misrepresented.
Metallic structures fabricated by welding are prone to defects, such as inclusions, porosities and cracking. The absence of significant defects is often achieved by radiography – the weld can be examined for internal defects using an S-ray or radioactive source and a suitable medium (plate of film).
During a large-scale steam boiler construction which required hundreds of internal tube welds and thousands of radiograph images, instances of film duplication were noticed by an inspector. Further investigation revealed large-scale falsification of weld images and shortcuts taken to reduce the time spent on site.