Characterization of oxide films formed on alloy 182 in simulated PWR primary water

The oxide film, formed on the alloy 182 due to the exposure to simulated Pressurized Water Reactor primary water conditions, is characterized using X-ray Photoelectron Spectroscopy, Scanning Electron Microscopy and Raman spectroscopy. As a consequence of the low redox potential for nickel, loosely bound oxide film consisting mainly of chromium oxide, is formed on the surface of the alloy. The oxide film is found to have a double-layer structure, with an inner layer rich in Cr2O3, outer layer rich in FeCr2O4. Thin Ni(OH)2 and Fe3O4 clusters were observed on top of the oxide film. The morphology and thickness of the layers critically depend on the exposure times and surface treatments prior to the exposure.