Spark plasma sintering of (U,Ce)O2 as a MOx nuclear fuel surrogate

Harrison, R. W.; Morgan, J.G.; Buckley, James J.; Abram, T.J.; Goddard, D. T.; Barron, Nicholas J.

doi:10.1016/j.jnucmat.2021.153302

Cited by 5 publications

(2 citation statements)

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“…Cerium dioxide (CeO 2 or ceria) is a lanthanide oxide that has been studied for decades due to its use in a wide range of industrial applications. CeO 2 is employed as an oxygen storage material in catalysis [1,2], a nanozyme in biomedical applications [3], a solid electrolyte in solid oxide fuel cells [4][5][6][7], and as a surrogate material for actinide oxide nuclear fuels [8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Structural dynamics of Schottky and Frenkel defects in CeO₂: a density-functional theory study

et al. 2023

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Cerium dioxide CeO2 (ceria) is an important material in catalysis and energy applications. The intrinsic Frenkel and Schottky defects can impact a wide range of material properties including the oxygen storage capacity, the redox cycle, and the ionic and thermal transport. Here, we study the impact of Frenkel and Schottky defects on the structural dynamics and thermal properties of ceria using density functional theory. The phonon contributions to the free energy are found to reduce the defect formation free energies at elevated temperature. The phonon dispersions of defective CeO2 show significant broadening of the main branches compared to stoichiometric ceria. Phonon modes associated with the defects are identifiable in the infrared spectra through characteristic shoulders on the main features of the stoichiometric fluorite structure. Finally, the presence of Frenkel and Schottky defects are also found to reduce the thermal conductivity by up to 88% compared to stoichiometric CeO2.

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Section: Introductionmentioning

confidence: 99%

Structural dynamics of Schottky and Frenkel defects in CeO₂: a density-functional theory study

et al. 2023

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“…The similarities between the crystallographic (Supplementary Table 1) and the thermodynamic properties of the U-Ce-O and U-Pu-O systems makes their oxidation and phase behavior quite comparable 35 . However, if the analogy between the two systems has been validated for MOX fuel fabrication, thermal and sintering behavior [36][37][38][39] , there is little evidence in the literature for similar alteration mechanism in aqueous solutions (at the noticeable exception of dissolution in concentrated nitric acid solutions [40][41][42] ). It is noteworthy that the Ce(IV) and Pu(IV) standard hydrolysis constants are close and the solubility of the two MO 2 oxides very low (Supplementary Table 1).…”

Section: Introductionmentioning

confidence: 99%

Oxidative dissolution of (U,Ce)O2 materials in aqueous solutions containing H2O2

et al. 2023

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Homogeneous and heterogeneous U1-xCexO2 (with 0≤ x≤ 0.25) materials were prepared via wet and dry chemistry routes, respectively before being submitted to dynamic leaching experiments. The feeding solution containing 0.20 mmol.L−1 H2O2 was kept under air and renewed to guarantee the stability of H2O2 during the experiment. Normalized alteration rates were determined from U concentration in the leachates. For homogeneous (U,Ce)O2 materials, the dissolution rate was divided by a factor of 3 when increasing the Ce content from 0.08 to 0.25. Surface characterizations revealed that studtite precipitated all over UO2 pellet surface and only on the UO2 grains of heterogeneous U0.92Ce0.08O2 samples. The behaviour of this heterogeneous material was similar to that observed for (U,Pu)O2 in the same conditions, which revealed the reliability of cerium as a plutonium analogue.

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Development and comparison of field assisted sintering techniques to densify CeO2 ceramics

Harrison

Morgan²,

Buckley³

et al. 2022

Journal of the European Ceramic Society

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Spark plasma sintering of (U,Ce)O2 as a MOx nuclear fuel surrogate

Cited by 5 publications

References 42 publications

Structural dynamics of Schottky and Frenkel defects in CeO₂: a density-functional theory study

Structural dynamics of Schottky and Frenkel defects in CeO₂: a density-functional theory study

Oxidative dissolution of (U,Ce)O2 materials in aqueous solutions containing H2O2

Development and comparison of field assisted sintering techniques to densify CeO2 ceramics

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Spark plasma sintering of (U,Ce)O2 as a MOx nuclear fuel surrogate

Cited by 5 publications

References 42 publications

Structural dynamics of Schottky and Frenkel defects in CeO2: a density-functional theory study

Structural dynamics of Schottky and Frenkel defects in CeO2: a density-functional theory study

Oxidative dissolution of (U,Ce)O2 materials in aqueous solutions containing H2O2

Development and comparison of field assisted sintering techniques to densify CeO2 ceramics

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Product

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Structural dynamics of Schottky and Frenkel defects in CeO₂: a density-functional theory study

Structural dynamics of Schottky and Frenkel defects in CeO₂: a density-functional theory study