Identification and quantification of hydride phases in Zircaloy-4 cladding using synchrotron X-ray diffraction |
| |
Authors: | RS Daum YS Chu AT Motta |
| |
Affiliation: | a Nuclear Engineering Division, Argonne National Laboratory, Argonne, IL 60439, United States b X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439, United States c Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA 16802, United States |
| |
Abstract: | Zirconium hydrides precipitate in fuel cladding alloys as a result of hydrogen uptake from the high-temperature corrosion environment of light water reactors. Synchrotron X-ray diffraction was performed at room temperature on stress-relieved Zircaloy-4 cladding with two distributions of hydrides - (1) uniformly distributed hydrides across the entire cladding wall and (2) hydride rim next to the outer surface. The δ-hydride phase was found to be the predominant hydride phase to precipitate for hydrogen contents up to 1250 weight parts per million (wt ppm). At a higher content, about 3000 wt ppm, although δ-hydride is still the majority phase, a significant amount of γ-hydride is also observed. At even higher hydrogen contents, in excess of approximately 6000 wt ppm, such as can occur in a highly dense hydride layer, peaks associated with the ε-hydride phase are also observed in the diffraction pattern. The volume fraction of hydrides was estimated as a function of hydrogen content using the integrated intensities of select diffraction peaks corresponding to the α-Zr matrix and the hydride phases. These estimated values agree well with calculated values from the independently measured concentrations. The results of this study indicate that hydride precipitation in Zircaloy-4 is a complex process of evolving hydride phases with increasing local hydrogen content. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|