HYDRIDE REORIENTATION IN ZIRCONIUM ALLOY NUCLEAR FUEL CLADDING STUDIED USING SYNCHROTRON RADIATION
Open Access
Author:
Jarvis, Jennifer Anne
Area of Honors:
Nuclear Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
Arthur Thompson Motta, Thesis Supervisor Arthur Thompson Motta, Thesis Supervisor Kimberly Colas, Thesis Supervisor Dr. Jack Brenizer Jr., Faculty Reader Arthur Thompson Motta, Thesis Honors Advisor
Keywords:
hydride zirconium zircaloy nuclear materials
Abstract:
During reactor operation, waterside corrosion of Zirconium alloy fuel cladding leads to hydrogen pickup. Hydrides platelets will normally precipitate circumferentially in the cladding. However, under temperature and load, the hydrides can reorient in the radial direction. These brittle radial hydrides can drastically reduce the ductility and the fracture toughness of the cladding.
This work contains an in-situ study of hydride reorientation. Using synchrotron radiation from the Advanced Photon Source (APS) at Argonne National Laboratory, x-ray diffraction in transmission geometry was used to study a hydrogen-charged sample under mechanical and thermal load. The sample was rolled Zircaloy-2 with a hydrogen content of 96 wt.ppm. It was studied under a loading cycle with temperature cycling from 25 to 400°C and with an applied tensile stress of 100 MPa. Under two cycles of loading, partial reorientation was achieved.
This diffraction data was used to perform an evaluation of the intensity, peak broadening, and peak shift of hydride peaks, in order to characterize the kinetics of reorientation. Additionally, the dissolution and precipitation temperatures were studied. Optical microscopy was used to compare the microstructure and hydride orientation before and after the experiment.
