Cerium as a Surrogate in the Plutonium Immobilized Form

Marra, James C.; Cozzi, A. D.; Pierce, Robert A.; Pareizs, J. M.; Jurgensen, A.; Missimer, David M.

doi:10.1002/9781118371435.ch36

Cited by 21 publications

(15 citation statements)

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“…The objective is to study the hydration of ceria surface with independent methods (IGC, Raman spectroscopy, ESEM and AFM) helping to validate these techniques for implementing on radioactive materials. Ceria is furthermore a classic surrogate for plutonium dioxide [39]. Oxides were prepared using the same procedure used for plutonium oxide in the PUREX process, that is to say oxalate calcination.…”

Section: Introductionmentioning

confidence: 99%

Effect of hydration and thermal treatment on ceria surface using non-intrusive techniques

Gaillard¹,

Venault²,

Calvet³

et al. 2014

Journal of Nuclear Materials

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International audienceThe evolution of plutonium dioxide surface due to water adsorption seems to influence H-2 generation through the radiolysis of adsorbed water. Surface evolution of ceria, a non-radioactive surrogate for plutonium dioxide, was investigated using Inverse Gas Chromatography (IGC), Raman spectroscopy, Environmental Scanning Electronic Microscopy (ESEM) and Atomic Force Microscopy (AFM). IGC highlights the complexity of ceria surface revealing three different adsorption sites on surface and indicate a surface evolution upon hydration. Thermal treatment appears to regenerate at least partially the initial surface state before hydration. IGC points out the influence of calcination temperature of ceria precursor on surface reactivity. The nature of surface modification was investigated by Raman spectroscopy which suggests formation of superficial hydroxide layer. ESEM and AFM were used to study potential surface topology modification upon superficial layer formation. Cerium hydroxide forms as a superficial layer with a nanostructure differing from the one of the oxide. (C) 2013 Elsevier B.V. All rights reserved

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Section: Introductionmentioning

confidence: 99%

Effect of hydration and thermal treatment on ceria surface using non-intrusive techniques

Gaillard¹,

Venault²,

Calvet³

et al. 2014

Journal of Nuclear Materials

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“…1,2,[21][22][23][24][25][26][27]11,[14][15][16][17][18][19][20] However, the thermophysical and thermochemical understanding of the low temperature polymorph of cerium disilicate (A-Ce 2 Si 2 O 7 ; space group P4 1 ) and the cation-vacant cerium oxyapatite (Ce 4.67 (SiO 4 ) 3 O; space group P6 3 /m) are still largely absent (Figure 1). Additionally, as Ce is the most abundant rare earth element 28 and an effective surrogate for Pu in the solid state system, [29][30][31][32][33] the thermodynamic properties of A-Ce 2 Si 2 O 7 and Ce 4.67 (SiO 4 ) 3 O are fundamentally needed for geochemical modeling and desirable for helping evaluate the thermodynamics of Pu in silicate solid systems.…”

Section: Introductionmentioning

confidence: 99%

High-Temperature Thermodynamics of Cerium Silicates, A-Ce₂Si₂O₇, and Ce_4.67(SiO₄)₃O

Strzelecki

Kriegsman

Estevenon

et al. 2020

ACS Earth Space Chem.

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Lanthanide disilicates and oxyapatites have potential roles in high temperature applications as thermal (TBC) and environmental barrier coatings (EBC), or possible alteration phases in geological nuclear waste respositories. However, those Ce 3+-bearing silicates have only been limitedly studied. In this work we performed detailed structural and thermodynamic investigations on ACe 2 Si 2 O 7 (tetragonal, P4 1) and Ce 4.67 (SiO 4) 3 O (hexagonal, P6 3 /m). The high temperature structural behaviors and coefficients of thermal expansion were determined by in situ high temperature synchrotron X-ray diffraction (HT-XRD) implemented with Rietveld analysis and thermogravimetric analysis coupled with differential scanning calorimetry (TGA-DSC). ACe 2 Si 2 O 7 was found to be stable in N 2 and air up to ~1483 K with an isotropic thermal expansion (α a = 12.3 × 10-6 K-1 and α c = 12.4 × 10-6 K-1). Ce 4.67 (SiO 4) 3 O had a slow partial oxidation between 533 K and 873 K to a new nonstoichemitric phase Ce 3+ 1.67-x Ce 4+ x Ce 3+ 3 (SiO 4) 3 O 1+0.5x , followed by a thermal decomposition to CeO 2 and SiO 2 at ~1000 K. By using high temperature oxide melt solution calorimetry at 973 K with lead borate as solvent, we determined, for the first time, the standard enthalpy of formation of ACe 2 Si 2 O 7 (-3825.1 ± 6.0 kJ/mol) and Ce 4.67 (SiO 4) 3 O (-7391.3 ± 9.5 kJ/mol). These thermodynamic paramters were compared with those of CeO 2 , CeSiO 4 , and other silicate oxyapatites for examining their chemical stability in high temperature environments relevent for aeronautical applications, mineral formation, and nuclear fuel cycle.

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“…Cerium, a lanthanide series metal, is a common chemical surrogate for plutonium. Cerium metal has similar physical and chemical properties to plutonium [14], and previous studies have used cerium as a nonradioactive substitute for plutonium to gain insights into plutonium behavior [15][16][17][18]. This use of cerium makes it a substance of interest to the nuclear forensics community.…”

Section: Introductionmentioning

confidence: 99%

“…In order to circumvent this problem, a stabilizer, such as gallium, is added in small amounts to the plutonium and alloyed through an annealing process. This stabilizes the δ phase at room temperature, allowing the metal to be machined [14]. Cerium can also be alloyed with gallium; Ce-Ga alloys have similar properties to Pu-Ga alloys, and studying them can provide useful insights into the behavior of Pu-Ga metals [15,17].…”

Section: Introductionmentioning

confidence: 99%

Quantitative Analysis of Cerium-Gallium Alloys Using a Hand-Held Laser Induced Breakdown Spectroscopy Device

Rao

Cook

Hall

et al. 2019

Atoms

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A hand-held laser-induced breakdown spectroscopy device was used to acquire spectral emission data from laser-induced plasmas created on the surface of cerium-gallium alloy samples with Ga concentrations ranging from 0–3 weight percent. Ionic and neutral emission lines of the two constituent elements were then extracted and used to generate calibration curves relating the emission line intensity ratios to the gallium concentration of the alloy. The Ga I 287.4-nm emission line was determined to be superior for the purposes of Ga detection and concentration determination. A limit of detection below 0.25% was achieved using a multivariate regression model of the Ga I 287.4-nm line ratio versus two separate Ce II emission lines. This LOD is considered a conservative estimation of the technique’s capability given the type of the calibration samples available and the low power (5 mJ per 1-ns pulse) and resolving power ( λ / Δ λ = 4000) of this hand-held device. Nonetheless, the utility of the technique is demonstrated via a detailed mapping analysis of the surface Ga distribution of a Ce-Ga sample, which reveals significant heterogeneity resulting from the sample production process.

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Cerium as a Surrogate in the Plutonium Immobilized Form

Cited by 21 publications

References 1 publication

Effect of hydration and thermal treatment on ceria surface using non-intrusive techniques

Effect of hydration and thermal treatment on ceria surface using non-intrusive techniques

High-Temperature Thermodynamics of Cerium Silicates, A-Ce₂Si₂O₇, and Ce_4.67(SiO₄)₃O

Quantitative Analysis of Cerium-Gallium Alloys Using a Hand-Held Laser Induced Breakdown Spectroscopy Device

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Cerium as a Surrogate in the Plutonium Immobilized Form

Cited by 21 publications

References 1 publication

Effect of hydration and thermal treatment on ceria surface using non-intrusive techniques

Effect of hydration and thermal treatment on ceria surface using non-intrusive techniques

High-Temperature Thermodynamics of Cerium Silicates, A-Ce2Si2O7, and Ce4.67(SiO4)3O

Quantitative Analysis of Cerium-Gallium Alloys Using a Hand-Held Laser Induced Breakdown Spectroscopy Device

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High-Temperature Thermodynamics of Cerium Silicates, A-Ce₂Si₂O₇, and Ce_4.67(SiO₄)₃O