Raman spectroscopy coupled to principal component analysis for studying UO2 nuclear fuels with different grain sizes due to the chromia addition

Milena-Pérez, A.; Bonales, Laura J.; Rodríguez-Villagra, N.; Fernández, S.; Baonza, Valentı́n G.; Cobos, J.

doi:10.1016/j.jnucmat.2020.152581

Cited by 25 publications

(23 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The change in lattice parameters of UO 2 was less pronounced at lower oxygen potential (−510 kJ/mol O 2 ) compared to the samples sintered at higher oxygen potential (−420 kJ/mol O 2 ). That general lattice contraction, as observed with increasing initial Cr content, is consistent with previous experimental studies of and Cr doping of UO 2 [ 9 , 21 , 22 , 41 ]. In these references, the lattice contraction was attributed to U(V) formation due to charge balancing of the dopant cations.…”

Section: Resultssupporting

confidence: 92%

“…This was also true for sintering at −420 kJ/mol O 2 , but not as significantly. The values of Milena-Perez et al (2021) [ 22 ] followed a very similar trend as the new data presented here, whereas Bourgeois et al (2001) [ 23 ] produced larger grains in general, which may partly be explained by the advanced spray coating doping method used. Still, the trend of their data was also similar with increasing doping level.…”

Section: Discussionsupporting

confidence: 87%

“…Cr-doping was found to increase the sintered density in all cases when compared with the respective UO 2 reference. For the Cr-doped materials sintered at −510 kJ/mol O 2 , as usually done in other studies [ 21 , 22 ], the relationship between the processing parameters and the final density was more similar to pure UO 2 in the case of the CPM approach than with the WCM approach. At optimized conditions, the highest densities were reached with the WCM method, independent from the compaction pressure, whereas the CPM method yielded lower sintered densities.…”

Section: Discussionsupporting

confidence: 60%

“…The Cr-doped pellets of Silva et al (2021) [ 21 ] reached about 96% of the theoretical density at comparable conditions, close to the pellets prepared via CPM at −510 kJ/mol O 2 . In contrast, the samples prepared by Milena-Perez et al (2021) [ 22 ], which were sintered at an oxygen potential of about −510 kJ/mol O 2 , showed increasing porosity with increasing doping, as observed via SEM.…”

Section: Discussionmentioning

confidence: 85%

“…These are well established for traditional UO 2 fuels, but less so for modern fuels such as Cr doped UO 2 . Recent studies [ 9 , 21 , 22 ] on Cr doped UO 2 have typically utilized powder-milling methods involving UO 2 and Cr 2 O 3 powders. Although these are more time-efficient in execution than methods such as sol-gel or co-precipitation, they often result in less homogeneous samples.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Chromium Doped UO2-Based Ceramics: Synthesis and Characterization of Model Materials for Modern Nuclear Fuels

et al. 2021

View full text Add to dashboard Cite

Cr-doped UO2 as a modern nuclear fuel type has been demonstrated to increase the in-reactor fuel performance compared to conventional nuclear fuels. Little is known about the long-term stability of spent Cr-doped UO2 nuclear fuels in a deep geological disposal facility. The investigation of suitable model materials in a step wise bottom-up approach can provide insights into the corrosion behavior of spent Cr-doped nuclear fuels. Here, we present new wet chemical approaches providing the basis for such model systems, namely co-precipitation and wet coating. Both were successfully tested and optimized, based on detailed analyses of all synthesis steps and parameters: Cr-doping method, thermal treatment, reduction of U3O8 to UO2, green body production, and pellet sintering. Both methods enable the production of suitable model systems with a similar microstructure and density as a reference sample from AREVA. In comparison with results from the classical powder route, similar trends upon grain size and lattice parameter were determined. The results of this investigation highlight the significance of subtly different synthesis routes on the properties of Cr-doped UO2 ceramics. They enable a reproducible tailor-made well-defined microstructure, a homogeneous doping, for example, with lanthanides or alpha sources, the introduction of metallic particles, and a dust-free preparation.

show abstract

Section: Resultssupporting

confidence: 92%

Section: Discussionsupporting

confidence: 87%

Section: Discussionsupporting

confidence: 60%

Section: Discussionmentioning

confidence: 85%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Chromium Doped UO2-Based Ceramics: Synthesis and Characterization of Model Materials for Modern Nuclear Fuels

et al. 2021

View full text Add to dashboard Cite

show abstract

Characterisation of 3000 ppm Cr₂O₃ doped UO₂ and its precipitates

Devillaire

Desgranges

Tarisien

et al. 2023

J Raman Spectroscopy

View full text Add to dashboard Cite

The thermochemical state of UO 2 -based nuclear fuel is a key parameter for which experimental data are difficult to obtain. A new experimental procedure using in situ oxido-reduction indicators was applied to irradiated fuel, and we aim to use it with chromium-doped unirradiated UO 2 . Nevertheless, we had first to characterise the chemical state of the chromium precipitates in our sample before. Here, we present the method we used for statistical characterisation of these precipitates using several methods, amongst which Raman spectroscopy plays a major role. Moreover, the Raman spectra of the precipitates were interpreted as evidence of a uranium stabilised Cr 3 O 4 phase.

show abstract

Isotopic effect of oxygen on the Raman mapping of a polycrystalline uranium dioxide UO₂

Gaillard,

Sarrasin,

Panetier

et al. 2024

J Raman Spectroscopy

View full text Add to dashboard Cite

Uranium dioxide (UO2) is a widely studied material due to its use as fuel in pressurised water reactors (PWR), and Raman spectroscopy is a technique of choice to characterise the evolution of its microstructure. UO2 crystallises in a fluorite CaF2 (space group Fm‐3m) structure that gives rise to a unique Raman signature, the T2g band. However, several other bands are often detected whose attribution remains unclear. The present study gives new insights on the Raman spectrum of UO2 thanks to the combination of isotopic labelling with 18O and Raman imaging. In addition to the expected T2g, U2 (LO), 2LO and U3 bands, we have detected a doublet at 885 and 925 cm−1, a U* band at 555 cm−1 in some specific areas and two bands located at 367 and 1196 cm−1. All Raman bands shift under the effect of the replacement of 16O by 18O, excepting for the U* band that could not be detected anymore. The isotopic shift ratio could be determined for 20% and 30% 18O labelling. No discrepancy in band position is observed between grains and grain boundaries, except for the U2(LO) band. We also evidence a difference between the U defect bands and the 885 and 925 cm−1 doublet bands evolution under labelling, although the latter also seems to be connected to the presence of defects in the material.

show abstract

Raman spectroscopy coupled to principal component analysis for studying UO2 nuclear fuels with different grain sizes due to the chromia addition

Cited by 25 publications

References 52 publications

Chromium Doped UO2-Based Ceramics: Synthesis and Characterization of Model Materials for Modern Nuclear Fuels

Chromium Doped UO2-Based Ceramics: Synthesis and Characterization of Model Materials for Modern Nuclear Fuels

Characterisation of 3000 ppm Cr₂O₃ doped UO₂ and its precipitates

Isotopic effect of oxygen on the Raman mapping of a polycrystalline uranium dioxide UO₂

Contact Info

Product

Resources

About

Raman spectroscopy coupled to principal component analysis for studying UO2 nuclear fuels with different grain sizes due to the chromia addition

Cited by 25 publications

References 52 publications

Chromium Doped UO2-Based Ceramics: Synthesis and Characterization of Model Materials for Modern Nuclear Fuels

Chromium Doped UO2-Based Ceramics: Synthesis and Characterization of Model Materials for Modern Nuclear Fuels

Characterisation of 3000 ppm Cr2O3 doped UO2 and its precipitates

Isotopic effect of oxygen on the Raman mapping of a polycrystalline uranium dioxide UO2

Contact Info

Product

Resources

About

Characterisation of 3000 ppm Cr₂O₃ doped UO₂ and its precipitates

Isotopic effect of oxygen on the Raman mapping of a polycrystalline uranium dioxide UO₂