In this extensive, 2 days, masterclass the different forms of CUI (atmospheric corrosion) and the parameters affecting these corrosion phenomena are explained and elaborated by means of numerous case histories. The measures to mitigate CUI are outlined in the several phases of plant life: design, construction, and operation/maintenance phase.  It is emphasized that inspection on CUI based on an RBI philosophy is required to set up a predictive maintenance program to ensure continuous safe plant operation.