Identification and quantification of hydride phases in Zircaloy-4 cladding using synchrotron x-ray diffraction.

Journal Article · Sat Aug 01 04:00:00 EDT 2009 · J. Nucl. Mater.

DOI:https://doi.org/10.1016/j.jnucmat.2009.04.004· OSTI ID:985625

Daum, R S; Chu, Y S; Motta, A T

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 {delta}-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 {delta}-hydride is still the majority phase, a significant amount of {gamma}-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 {epsilon}-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 {alpha}-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.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: SC; NRC
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 985625
• Report Number(s): ANL/NE/JA-62450
• Journal Information: J. Nucl. Mater., Journal Name: J. Nucl. Mater. Journal Issue: 3 ; Aug. 1, 2009 Vol. 392; ISSN 0022-3115
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

08 HYDROGEN
36 MATERIALS SCIENCE
43 PARTICLE ACCELERATORS
ALLOYS
CORROSION
DIFFRACTION
HYDRIDES
HYDROGEN
PRECIPITATION
SYNCHROTRONS
WATER
X-RAY DIFFRACTION
ZIRCALOY 4
ZIRCONIUM HYDRIDES