First-principles study of thermophysical properties of interaction layer products in U-Mo/Al dispersion fuel

Journal Article · Fri Nov 02 00:00:00 EDT 2018 · Journal of Nuclear Materials

DOI:https://doi.org/10.1016/j.jnucmat.2018.10.049· OSTI ID:1483640

Mei, Zhi -Gang ^[1]; Yacout, Abdellatif M. ^[1]

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1. Argonne National Lab. (ANL), Argonne, IL (United States)

Thermophysical properties of interaction layer (IL) formed in U-Mo/Al dispersion fuel are important for the evaluation of its impact on the fuel performance. Binary and ternary phases observed in the IL, however, are not well studied yet. Recently we predicted the thermophysical properties of the binary U-Al compounds in U-Al system using density functional theory (DFT) calculations. In this paper, we investigated the structural, elastic, electronic, vibrational and thermodynamic properties of the ternary U-Mo-Al compounds formed in IL, including (U_0.75,Mo_0.25)Al₃, U₆Mo₄Al₄₃ and UMo₂Al₂₀, using DFT calculations. The polycrystalline aggregate properties of these compounds were obtained from the predicted single crystal elastic constants. The calculated electronic density of states confirm that all of the compounds exhibit typical metallic behavior with the majority states at the Fermi level dominated by U 5f electrons. Using quasi-harmonic approximation, we predicted the thermodynamic properties of these compounds by including both electronic and lattice contributions. We also investigated the effect of density on the thermodynamic properties of (U_0.75,Mo_0.25)Al₃ phase. Here, the current results are expected to be helpful to the modeling of the fuel performance of U-Mo/Al dispersion fuel and the thermodynamic modeling of the ternary U-Mo-Al system.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: AC02-06CH11357; NA-23
• OSTI ID: 1483640
• Alternate ID(s): OSTI ID: 1635938
• Journal Information: Journal of Nuclear Materials, Vol. 513, Issue C; ISSN 0022-3115
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

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