Formation of multicomponent alloy particles in doped ceria under I2+ ion irradiation and thermal annealing

JOURNAL OF NUCLEAR MATERIALS

卷:545

Article

Kruska, Karen¹  Jiang, Weilin¹  Wang, Xuemei²  Shao, Lin²  Riley, Brian J.¹  Devanathan, Ram¹ 

[1] Pacific Northwest Natl Lab, Energy & Environm Directorate, POB 999, Richland, WA 99352 USA

[2] Texas A&M Univ, Dept Nucl Engn, College Stn, TX 77843 USA

关键词: Multicomponent Alloy;    epsilon-phase;    STEM-EDS;    surrogate fuel;    Tc waste form;    ion irradiation;    I fission gas;    heat treatment;   

DOI  :  10.1016/j.jnucmat.2020.152638

来源: Elsevier

【 摘 要 】

Multicomponent alloys resembling the epsilon-phase particles in nuclear fuel have the potential to immobilize Tc-99 in a stable waste form. Formation of such multicomponent alloys under extreme conditions is studied in a non-activated model system: CeO2 doped with 2 wt.% Mo, 1.5 wt.% Ru, 0.75 wt.% Pd, 0.5 wt.% Re and 0.25 wt.% Rh. The doped CeO2 films were irradiated with I2+ ions (610 degrees C, 10(16) and 5x10(16) I2+/cm(2)). For selected samples post-irradiation heat treatment was conducted (900 degrees C, 1100 degrees C). Analytical transmission electron microscopy revealed the formation of 5-20 nm precipitates containing Pd, Mo, and Re sometimes associated with cavities. Iodine was found to segregate to grain boundaries and cracks. After heat treatment at 1100 degrees C, the CeO2 matrix had recrystallized. Precipitates containing Pd, Mo, Re, and Ru were observed near the interface with the polycrystalline yttria-stabilized zirconia substrate. It follows that Pd is the most mobile element, followed by Mo and Re. While irradiation promotes precipitation, high-temperature effects are more significant. (C) 2020 Elsevier B.V. All rights reserved.

【 授权许可】

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