Abstract
Neutron prompt gamma-ray analysis has been used to measure the changes in wall thickness of iron pipes due to corrosion, as well as to determine the type and amount of scale that may accumulate inside pipes at desalination plants. The intensities of the 7.632 and 7.646 MeV gamma rays of iron were linear within the iron wall thickness of interest. Elements of interest in scale were Ca, S and Si and were found in different compounds. The intensities of emitted photons from CaSO
4, for example, were found to increase with scale thickness. The technique can provide information on the corrosion of pipes and the amount and type of scale simultaneously while the plant is in operation.