Novel insights in the study of water penetration into polycrystalline UO2 by secondary ion mass spectrometry

Marchetti, Ilaria; Belloni, F.; Himbert, Jérôme; Carbol, Paul; Fanghänel, Thomas

doi:10.1016/j.jnucmat.2010.10.065

Cited by 7 publications

(8 citation statements)

References 17 publications

(34 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Depth profiles acquired on polycrystalline UO 2 and reported in previous works showed the presence of two different diffusion regimes. This is highlighted in Fig.…”

Section: Resultssupporting

confidence: 56%

“…The samples investigated are single‐crystal UO 2 (cut orientation [420]), a commercial nat. UO 2 pellet from Siemens A.G . and SIMFUEL 8% from AECL, Canada …”

Section: Methodsmentioning

confidence: 99%

“…Average depth profiles were calculated typically from 4–6 profiles acquired in identical conditions on each sample: the uncertainty of each experimental point was then calculated as the standard deviation of the individual measurements. The sputter rate was determined by profilometry and was used to convert every profile from time to depth scale.…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Room‐temperature diffusion coefficients for oxygen and water in UO₂ matrices: a SIMS study

Marchetti

Carbol

Himbert

et al. 2012

Surface & Interface Analysis

View full text Add to dashboard Cite

To understand the mechanism of fuel oxidation, in the event of exposure of spent nuclear fuel to groundwater in a final repository, the key parameters are the diffusion coefficients for oxygen and water in UO 2 . In the temperature range relevant for geological disposal (20-100 C), we conducted static corrosion experiments, for 3-6 months, with 18 O-labelled water on different UO 2 matrices (single-crystal, polycrystalline UO 2 , SIMFUEL) so that we could evaluate the penetration of the 18 O-tracer by means of secondary ion mass spectrometry depth profiling, measuring the 18 O/ 16 O ratio. Fick's second law was applied to fit the diffusion profiles in the single crystal and to determine the chemical diffusion coefficient of oxygen, which was found to be in good agreement with the Arrhenius plot extrapolation from high-temperature literature data. Profiles of polycrystalline UO 2 could be fitted with the Levine-MacCallum model, showing that grain boundaries behave like high-diffusivity paths. The presence of secondary phases precipitated along the grain boundaries, as in the case of SIMFUEL, showed a hindering effect for this grain-boundary diffusion, reducing the measured penetration depth.

show abstract

“…Depth profiles acquired on polycrystalline UO 2 and reported in previous works showed the presence of two different diffusion regimes. This is highlighted in Fig.…”

Section: Resultssupporting

confidence: 56%

“…The samples investigated are single‐crystal UO 2 (cut orientation [420]), a commercial nat. UO 2 pellet from Siemens A.G . and SIMFUEL 8% from AECL, Canada …”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Room‐temperature diffusion coefficients for oxygen and water in UO₂ matrices: a SIMS study

Marchetti

Carbol

Himbert

et al. 2012

Surface & Interface Analysis

View full text Add to dashboard Cite

show abstract

“…4 Depth profiling beneath the UO 2 pellet surface at room temperature indicates oxygen diffusion into the UO 2 lattice, while water species diffusion occurs along grain boundaries, behaving as high-diffusivity paths. 5 The use of the oxygen isotopic composition ( 18 O/ 16 O� expressed in δ notation as δ 18 O vs VSMOW) as a signature for geolocation 6−8,11−13 and the process history 9,10,15−18 of uranium oxides for nuclear forensics applications 14 have gained much interest in recent years. The δ 18 O variation of naturally occurring uranium ore minerals is in the range of −32 to +11‰.…”

Section: Introductionmentioning

confidence: 99%

“…Volume diffusion was also considered the primary process controlling oxygen diffusion in polycrystalline and single-crystalline UO 2 in the temperature range of 605–750 °C . Depth profiling beneath the UO 2 pellet surface at room temperature indicates oxygen diffusion into the UO 2 lattice, while water species diffusion occurs along grain boundaries, behaving as high-diffusivity paths …”

Section: Introductionmentioning

confidence: 99%

Oxygen Isotope Alterations during the Reduction of U₃O₈ to UO₂ for Nuclear Forensics Applications

Assulin,

Yam,

Grego-Shnaiderman

et al. 2023

ACS Omega

View full text Add to dashboard Cite

The fabrication of UO 2 from U 3 O 8 is an essential reaction in the nuclear fuel cycle. The oxygen isotope fractionation associated with this reaction has significant implications in the general field of nuclear forensics. Hence, the oxygen isotope fractionation during the reduction of U 3 O 8 to UO 2 was determined in the temperature range of 500−700 °C and for a duration of 2 to 6 h under a high-purity H 2 atmosphere. Three U 3 O 8 samples, possessing a different oxygen isotopic composition, were used to investigate key parameters involved with the fractionation during the reduction process. All UO 2 products did not maintain the original isotope composition of the starting U 3 O 8 under all conditions. The results show that the system UO 2 −H 2 O attains isotope equilibrium at 600 °C, provided the reduction process lasts at least 4 h or more. At 600 °C, UO 2 was isotopically depleted by 2.89 ± 0.82‰ compared to the U 3 O 8 from which it was produced. We find that the H 2 O formed during the reduction plays a major role in determining the final δ 18 O of UO 2 prepared from U 3 O 8. The isotope equilibrium of the system UO 2 −H 2 O at 600 °C was calculated, indicating that δ 18 O of the H 2 O was enriched by about 11‰ relative to the UO 2 due to the uranium mass effect. These findings could potentially have important implications for nuclear forensics, as they provide a new method for determining the history of UO 2 samples and tracing back their production process.

show abstract

Spent Nuclear Fuel as Waste Material

Carbol¹,

Detlef²,

Thierry³

et al. 2020

Comprehensive Nuclear Materials

View full text Add to dashboard Cite

Novel insights in the study of water penetration into polycrystalline UO2 by secondary ion mass spectrometry

Cited by 7 publications

References 17 publications

Room‐temperature diffusion coefficients for oxygen and water in UO₂ matrices: a SIMS study

Room‐temperature diffusion coefficients for oxygen and water in UO₂ matrices: a SIMS study

Oxygen Isotope Alterations during the Reduction of U₃O₈ to UO₂ for Nuclear Forensics Applications

Spent Nuclear Fuel as Waste Material

Contact Info

Product

Resources

About

Novel insights in the study of water penetration into polycrystalline UO2 by secondary ion mass spectrometry

Cited by 7 publications

References 17 publications

Room‐temperature diffusion coefficients for oxygen and water in UO2 matrices: a SIMS study

Room‐temperature diffusion coefficients for oxygen and water in UO2 matrices: a SIMS study

Oxygen Isotope Alterations during the Reduction of U3O8 to UO2 for Nuclear Forensics Applications

Spent Nuclear Fuel as Waste Material

Contact Info

Product

Resources

About

Room‐temperature diffusion coefficients for oxygen and water in UO₂ matrices: a SIMS study

Room‐temperature diffusion coefficients for oxygen and water in UO₂ matrices: a SIMS study

Oxygen Isotope Alterations during the Reduction of U₃O₈ to UO₂ for Nuclear Forensics Applications