X-Ray Photoelectron Spectroscopy Investigations on Hydrided Zy-4 Fuel Cladding

Zirconium chemical states have been assessed using X-ray photoelectron spectroscopy (XPS) measurements on Zy-4 fuel cladding tube hydrided at 96 ppm in order to explore the surface chemical modifications. In-depth chemical profiling reveals an increasing zirconium hydride content from 1.9% to 3.0% due to a decreased ubiquitous carbon surface contaminant. Additionally, the diminishing OH groups concentration was successfully associated with the decreasing ZrOx(OH)y chemical state content, from 98.1% to 76.7%, respectively, suggesting a depleted moisture amount with depth. Furthermore, by depth profiling the surface for 30s, the zirconium fully oxidized (ZrO2) was highlighted indicating the presence of the passivating oxide layer.(author)