The effects of Xe/Cs occupation on the thermal transport properties of U3Si: A first-principles study

Feng, Shaomin; Deng, Yuhui; Zhao, Shunzheng; Li, Buda; Qi, Hangbo; Gong, Hengfeng; Ren, Qisen; Liao, Yehong; Zu, Xihong; Xiao, Haiyan

doi:10.1016/j.jnucmat.2023.154657

Cited by 2 publications

(2 citation statements)

References 63 publications

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“…Besides, similar to the case of σ, with the occupation of Xe and Cs, the κ e of U 3 Si 2 decreases under a constant temperature. Feng et al [79] also reported that the κ e of U 3 Si with FP occupation are significantly reduced. In particular, with U1 site being occupied by Xe and Cs, the κ e of U 3 Si 2 decreases from 6.42 W mK −1 to 2.79 W mK −1 and to 2.39 W mK −1 at 300 K, respectively.…”

Section: Electronic Transport Properties Of Ideal and Defective U 3 Simentioning

confidence: 95%

The effect of fission products Xe and Cs on the thermal conductivity of the U₃Si₂ lattice: a first-principles study

Qi,

Li,

et al. 2023

J. Phys.: Condens. Matter

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In the past decades, uranium silicide (U3Si2) as a promising accident tolerant fuel (ATF) has drawn considerable attention in the field of nuclear physics. In comparison with traditional nuclear fuel (UO2), the U3Si2 has higher thermal conductivity and uranium density, thereby resulting in lower centerline temperatures and better fuel economy. However, during the nuclear fission reaction, some unexpected fission products, such as Xe and Cs, are released and form the defective states. In this study, we explore the influence of Xe and Cs on the thermal conductivity of the U3Si2 lattice from 200 to 1500 K using density functional theory calculations combined with Boltzmann transport equation. Our results reveal that the lattice and electronic thermal conductivities of defective U3Si2 are reduced at a constant temperature, as compared with that of ideal system, thus resulting in a decrease of the total thermal conductivity. In the case of Cs occupation at U1 site, the total thermal conductivity (4.42 W/mK) is decreased by ~56 % at 300 K, as compared with the value of 9.99 W/mK for ideal system. With U1 and Si sites being occupied by Xe, the total thermal conductivities (4.45 and 6.52 W/mK) are decreased by ~55 % and 35 % at 300 K, respectively. The presented results suggest that the U3Si2 has potential as a promising ATF at high temperatures.

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Section: Electronic Transport Properties Of Ideal and Defective U 3 Simentioning

confidence: 95%

The effect of fission products Xe and Cs on the thermal conductivity of the U₃Si₂ lattice: a first-principles study

Qi,

Li,

et al. 2023

J. Phys.: Condens. Matter

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“…Uranium dioxide (UO 2 ) is of a fluorite structure in which the cations are located in a face-centered cubic (fcc) sublattice and the anions are in a cubic sublattice [30]. The U 3 Si crystal is of a tetragonal structure with the space group I4/mcm [50]. The UO 2 has 12 atoms in the unit cell and the U 3 Si has 16 atoms in the unit cell.…”

Section: Methodsmentioning

confidence: 99%

Ab Initio Molecular Dynamics Study of Electron Excitation Effects on UO2 and U3Si

Jin,

Zhao,

Xiao

2023

Materials

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In this study, an ab initio molecular dynamics method is employed to investigate how the microstructures of UO2 and U3Si evolve under electron excitation. It is found that the U3Si is more resistant to electron excitation than UO2 at room temperature. UO2 undergoes a crystalline-to-amorphous structural transition with an electronic excitation concentration of 3.6%, whereas U3Si maintains a crystalline structure until an electronic excitation concentration reaches up to 6%. Such discrepancy is mainly due to their different electronic structures. For insulator UO2, once valence U 5f electrons receive enough energy, they are excited to the conduction bands, which induces charge redistribution. Anion disordering is then driven by cation disordering, eventually resulting in structural amorphization. As for metallic U3Si, the U 5f electrons are relatively more difficult to excite, and the electron excitation leads to cation disordering, which eventually drives the crystalline-to-amorphous phase transition. This study reveals that U3Si is more resistant to electron excitation than UO2 under an irradiation environment, which may advance the understanding of related experimental and theoretical investigations to design radiation-resistant nuclear fuel uranium materials.

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The effects of Xe/Cs occupation on the thermal transport properties of U3Si: A first-principles study

Cited by 2 publications

References 63 publications

The effect of fission products Xe and Cs on the thermal conductivity of the U₃Si₂ lattice: a first-principles study

The effect of fission products Xe and Cs on the thermal conductivity of the U₃Si₂ lattice: a first-principles study

Ab Initio Molecular Dynamics Study of Electron Excitation Effects on UO2 and U3Si

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The effects of Xe/Cs occupation on the thermal transport properties of U3Si: A first-principles study

Cited by 2 publications

References 63 publications

The effect of fission products Xe and Cs on the thermal conductivity of the U3Si2 lattice: a first-principles study

The effect of fission products Xe and Cs on the thermal conductivity of the U3Si2 lattice: a first-principles study

Ab Initio Molecular Dynamics Study of Electron Excitation Effects on UO2 and U3Si

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Product

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The effect of fission products Xe and Cs on the thermal conductivity of the U₃Si₂ lattice: a first-principles study

The effect of fission products Xe and Cs on the thermal conductivity of the U₃Si₂ lattice: a first-principles study