The influence of hydrogen on oxygen distribution inside Zry-4 fuel cladding

This study is concerned with oxygen concentration measurements inside the Zry-4 fuel cladding wall after high-temperature oxidation. The oxygen distribution has been determined using the WDS method and also by nanohardness measurement. The relationship between the nanohardness and the oxygen concentration at the α/β phase boundary in the α-Zr(O) region has been explored. The hydrogen influence on the oxygen distribution was examined. The results were compared with results of other authors, showing satisfactory agreement. It was concluded that the oxygen concentration measurement inside the cladding wall after the isothermal high-temperature oxidation could be used for constructing the Zr-alloy–Oxygen phase diagram.