Integration of Human Factors in Offshore Risk Assessment

Gamma scanning is one of the most widely used nuclear inspection techniques worldwide to troubleshoot industrial equipment in refineries and petrochemical plants. The technique simply involves a sealed radiation source (Nal(TI)) paired with a radiation detector positioned on opposite sides of the equipment to be tested.  The pair moves simultaneously alongside the lenght of the equipment generating a one-dimensional density profile. Despite a few incremental improvements proposed over the years (including automated and remote scanning, wireless detectors and new field and data output programs), the technique remains essentially unchanged since first proposed decades ago and its usage still results in a one-dimensional median density profile of the target. The present work (developed as part of the requirement for a Master of Science degree) describes a new approach for gamma scanning that generates a two-dimensional density distribution plot using industrial tomography tools. This two-dimensional image reveals far more information on the equipment under analysis, information not previously available under conventional testing, and represents a significant advance in non destructive testing of this type of equipment. The inventors of this innovative technology (patent pending) were awarded Petrobras' 2013 Technology Prize in the category of Master Degree - Refining and Petrochemicals.