Hydride precipitation kinetics in Zircaloy-4 studied using synchrotron X-ray diffraction

Journal Article · Thu Jan 01 00:00:00 EST 2015 · Journal of Nuclear Materials

DOI:https://doi.org/10.1016/j.jnucmat.2015.02.035· OSTI ID:1239572

Courty, Olivier Fabrice; Motta, Arthur T.; Piotrowski, Christopher J.; Almer, Jonathan D.

As a result of in-reactor corrosion during operation in nuclear reactors, hydrogen can enter the zirconium fuel cladding and precipitate as brittle hydride particles, which may reduce cladding ductility. Dissolved hydrogen responds to temperature gradients, resulting in transport and precipitation into cold spots so that the distribution of hydrides in the cladding is inhomogeneous. The hydrogen precipitation kinetics plays a strong role in the spatial distribution of the hydrides in the cladding. The precipitation rate is normally described as proportional to the supersaturation of hydrogen in solid solution. The proportionality constant, α2, for hydride precipitation in Zircaloy-4 is measured directly using in situ synchrotron X-Ray diffraction, at different temperatures and with three different initial hydrogen concentrations. The results validate the linear approximation of the phenomenological model and a near constant value of α2 = 4.5 × 10^-4 s^-1 was determined for the temperature range studied.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy - Nuclear Energy University Programs (NEUP); USDOE Office of Science (SC), Basic Energy Sciences (BES)
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1239572
• Journal Information: Journal of Nuclear Materials, Vol. 461; ISSN 0022-3115
• Publisher: Elsevier
• Country of Publication: United States
• Language: English