Results of process equipment imaging by tomographic gamma scan

Abstract

Gamma scanning is a nuclear inspection technique widely used for troubleshooting industrial process equipments in refineries and petrochemicals. A radiation source and detector move vertically along the height of the vessel and the radiation readings are used to plot the graph of density profile. In recent years, many improvements have been added to this technique, but essentially the result of gamma scanning still consists of a 1-D density plot. Developed in 2012, the tomographic gamma scan uses image reconstruction techniques to show the result of gamma scan as a 2-D density distribution image. In this work, we present the current status of the technology and the results obtained by applying the technique to real operating process equipment. The results present images that match well with the 1-D density plots obtained by the conventional gamma scan and reveal process and operational problems that has never been visualized before with the traditional technique. The tomographic gamma scan can be immediately applied in practice with low financial investment.