The Evaluation of the Primary Circuit Passivation Layer Formed After Hot Functional Tests at the EMO3
Abstract The presented article outlines and describes the processes involved in the creation and testing of the passivation layer that was created during hot functional tests at the third unit of NPP Mochovce. The article is divided into several sections. In the first section is the description of the hot tests on the third block, in particular the chemical regime, i.e the formation of hydrogen or the necessary adjustment of the pH value. The second section of the article describes the evaluation of the passivation layer using instrumental techniques, i.e. Raman microscopy, Scanning electron microscopy, X-Ray Photoelectron Spectroscopy and others. The results obtained by using these techniques provided a comprehensive view of the resulting layer and clearly defined it's structure. The measurement revealed that a passivation layer was formed, the inner layer of which is enriched with a chrome element. The upper part of the passivation layer was composed of iron oxides, mainly magnetite.