Scanning Electron Microscopy and Energy Dispersive X-ray Microanalysis of Nuclear Reactor Corrosion Particles

Abstract

The nature and origin of particulates in the heat transport system of CANDU water-cooled nuclear reactors are relevant to the operation of these stations. The analysis of corrosion particles is difficult because of their small size and low concentration. A scanning electron microscope equipped with an X-ray analyzer has been used successfully for the simultaneous characterization of the morphology, size, and elemental composition of these particles. The good resolution and the large depth of field of the scanning electron microscope are suited for the examination of micron-sized particles. Also, the solid state Si (Li) detection system is readily amenable to automated data manipulation and thus permits a rapid qualitative assay of a representative number of particles from any given sample. In this study, individual particles having masses as low as 10-15 g have been analyzed and X-rays arising from electron capture decay of 55Fe have been observed in some of the samples. The techniques discussed are potentially applicable to a variety of problems related to the quality of environmental waters.