Microstructure studies of interdiffusion behavior of U3Si2/Zircaloy-4 at 800 and 1000 °C

Abstract

Fuel swelling during normal reactor operations could lead to unfavorable chemical interactions when in contact with its cladding. As new fuel types are developed, it is crucial to understand the interaction behavior between fuel and its cladding. Diffusion experiments between U 3 Si 2 and Zricaloy-4 (Zry-4) were conducted at 800 and 1000C up to 100 hours. The microstructure of pristine U 3 Si 2 and U 3 Si 2 /Zry-4 interdiffusion products were examined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) equipped with an energy dispersive X-ray spectroscopy (EDS) system. The primary interdiffusion product observed at 800C

Effect of High Si Content on U3Si2 Fuel Microstructure

“…The fuel matrix was confirmed to be U3Si2 by both XRD and SAD. The phases found in this analysis are in agreement with the TEM results reported in [15]. In the TEM and SAD examinations, not all the secondary phases were found due to the small volume of the TEM specimen.…”

CHARACTERIZATION OF DIRECT ADDITIVE MANUFACTURED U3Si2 SURROGATE TO PREDICT U3Si2 MICROSTRUCTURES

“…The fuel matrix was confirmed to be U3Si2 by both XRD and SAD. The phases found in this analysis are in agreement with the TEM results reported in[75]. In the TEM and SAD examinations not all the secondary phases were found, due to the smaller volume of the TEM specimen.…”

“…The presence of oxygen is attributed to surface oxide of the sample powders as well as potential O2 impurities found in the argon filled glovebox where the fabrication took place. Oxidation of metallic uranium aids in the formation of silicon-rich USi phases while employing uranium and silicon powders in a stoichiometric ratio to form U3Si2.The phases found in the TEM analyses performed in this research project were in close agreement with other literature evaluating silicide (U3Si2) fuel[17][19][75]. Future work will evaluate the interphase of USi and UO2 grains found in the fuel matrix.X-Ray DiffractionX-ray diffraction (XRD) spectroscopy was performed on the U3Si2 fuel samples in order to evaluate the different phases present.…”

Caracterização e quantificação de fases em ligas de urânio-silício para aplicação como combustível nuclear

“…Cabe também salientar que o alumínio usado na dispersão do siliceto melhora a resistência à oxidação do combustível93 e o U 3 Si 2 é compatível com os revestimentos de Zircalloy-4, comumente usado em reatores de potência112 , e com novos revestimentos estudados, como o FeCrAl113 . Por sua vez, óxidos acima de 1000 ºC, o crescimento se torna anisotrópico e um novo pico de difração é observado, por conta de mudança de posições atômicas, concentração de defeitos ou mudança de grupo espacial.…”