Density-functional study of bcc U–Mo, Np–Mo, Pu–Mo, and Am–Mo alloys

Landa, A.; Söderlind, Per; Turchi, P. E. A.

doi:10.1016/j.jnucmat.2012.11.033

Cited by 11 publications

(7 citation statements)

References 52 publications

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“…When treating compositional disorder, the EMTO method is combined with the coherent potential approximation (CPA) [24]. For instance, the EMTO-CPA formalism has been successfully used to describe thermodynamic properties of the metallic nuclear fuels, including: U-Zr, U-Mo, Pu-Zr, Pu-Mo, Pu-U, Pu-Np, Pu-Am, U-Ti, U-Nb, Np-Mo, Pu-Mo, for fast breeder reactors [29][30][31][32][33][34][35][36].…”

Section: Electronic Structure Calculationsmentioning

confidence: 99%

Development of a CALPHAD Thermodynamic Database for Pu-U-Fe-Ga Alloys

et al. 2019

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The interaction of actinides and actinide alloys such as the δ-stabilized Pu-Ga alloy with iron is of interest to understand the impurity effects on phase stability. A newly developed and self-consistent CALPHAD thermodynamic database is presented which covers the elements: Pu, U, Fe, Ga across their whole composition and temperature ranges. The phase diagram and thermodynamic properties of plutonium-iron (Pu-Fe) and uranium-iron (U-Fe) systems are successfully reassessed, with emphasis on the actinide rich side. Density functional theory (DFT) calculations are performed to validate the stability of the stoichiometric (Pu,U)6Fe and (Pu,U)Fe2 compounds by computing their formation enthalpies. These data are combined to construct the Pu-U-Fe ternary phase diagram. The thermodynamic assessment of Fe-Ga is presented for the first time and application to the quaternary Pu-U-Fe-Ga system is discussed.

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Section: Electronic Structure Calculationsmentioning

confidence: 99%

Development of a CALPHAD Thermodynamic Database for Pu-U-Fe-Ga Alloys

et al. 2019

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“…Both above mentioned systems are known to have only one stable compound at room temperature, which are the U 2 Mo in the I4/mmm space group [3] and the δ-UZr 2 phase with P 6/mmm space group [4][5][6] . These phases gradually transforms into a bcc solid solution with increasing temperature [7] .…”

Section: Introductionmentioning

confidence: 99%

On the ground state of the U-Mo system

Losada

Garcés

2019

Journal of Nuclear Materials

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The ground state of the U-Mo system is studied in this work using an evolutionary algorithm coupled with ab initio calculations. This methodology is applied to several compositions, with a more detailed examination at the U-rich side. A new ground state is identified within an approach that considers structures for up to 3 formula units per cell. A supercell scheme based on the pure phase structure of each element is used for dilute compositions. The ground state at a pressure of 1 atm. is characterized by only two stable compounds: Ω-phase and a new phase, named α-U 15 Mo in this work, with a structure determined by adding a substitutional Mo impurity to a 1 × 2 × 2 supercell of α-U. A range of immiscibility of U in bcc-Mo based structures is extended from 0 to nearby 50 at. % of U. The new α-U 15 Mo phase comprising the ground state has similar features to those of the α -phase formed in quenched samples at room temperature. The internal relaxation of U atoms in this phase resembles the movements due to charge density waves observed in orthorhombic α 1 -U. The ground state of the U 15 Mo compound at T=0 K can not be fully identified due to the charge density wave associated with α-U. That structure could be a supercell based on the structurally undefined α 3 -U phase.

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“…Until to now, lots of different uranium alloys have been tested and the U-Mo alloy has been identified as a high performance fuel due to the high uranium density and the low neutron capture cross-section of Mo [2][3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

“…The presence of Xe bubbles in U-Mo alloy fuel can drastically change its mechanical properties and thermophysical properties, especially lead to an important swelling, which can have dramatic consequences for the safety of nuclear devices. This is the reason why lots of theoretical and experimental studies [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] have been undertaken to understand the behavior of this U-Mo alloy fuel under irradiation, especially the effect of fission gas bubbles on the fuel properties. However, the behavior of small Xe bubbles, especially the basic processes governing its migration, coalescence and the release of Xe atoms from the U-Mo alloy fuel, has not been understood clearly.…”

Section: Introductionmentioning

confidence: 99%