The prediction of nuclear fuel (UO2) dissolution rates under waste disposal conditions

Shoesmith, D.W.; Sunder, S.

doi:10.1016/0022-3115(92)90072-s

Cited by 117 publications

(69 citation statements)

References 26 publications

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“…6 Hence, the degree of nonstoichiometry in spent nuclear fuel has an important effect on its solubility and corrosion rate 7 which governs the release rate of the majority of radionuclides. 8 This work considers the explicit effect of radiation damage by fission fragments on nonstoichiometry in spent nuclear fuel and outlines a methodology developed for determining the degree of non-stoichiometry in UO 2+x . For this purpose, thin films of UO 2 on LSAT (lanthanum strontium aluminum tantalum oxide) and YSZ (yttria-stabilised zirconia) substrates were produced and irradiated with Xe and U ions, respectively.…”

Section: Introductionmentioning

confidence: 99%

XPS Study of Ion Irradiated and Unirradiated UO₂ Thin Films

et al. 2016

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XPS determination of the oxygen coefficient k O =2+x and ionic (U 4+ , U 5+ and U 6+ ) composition of oxides UO 2+x formed on the surfaces of differently oriented (hkl) planes of thin UO 2 films on LSAT (Al 10 La 3 O 51 Sr 14 Ta 7 ) and YSZ (yttria-stabilized zirconia) substrates was performed. The U 4f and O 1s core-electron peak intensities as well as the U 5f relative intensity before and after the 129 Xe 23+ and 238 U 31+ irradiations were employed. It was found that the presence of uranium dioxide film in air results in formation of oxide UO 2+x on the surface with mean oxygen coefficients k O in the range 2.07-2.11 on LSAT and 2.17-2.23 on YSZ substrates. These oxygen coefficients depend on the substrate and weakly on the crystallographic orientation.On the basis of the spectral parameters it was established that uranium dioxide films AP2,3 on the LSAT substrates have the smallest k O values, and from the XRD and EBSD results it follows that these samples have a regular monocrystalline structure. The XRD and EBSD results indicate that samples AP5-7 on the YSZ substrates have monocrystalline structure, however, they have the highest k O values. The observed difference in the k O values, probably, caused by the different nature of the substrates: the YSZ substrates provide 6.4% compressive strain, whereas (001) LSAT substrates result only in 0.03% tensile strain in the UO 2 films.129 Xe 23+ irradiation (92 MeV, 4.8 × 10 15 ions/cm 2 ) of uranium dioxide films on the LSAT substrates was shown to destroy both long range ordering and uranium close environment, which results in increase of uranium oxidation state and regrouping of oxygen ions in uranium close environment. 238 U 31+ (110 MeV, 5 × 10 10 , 5 × 10 11 , 5 × 10 12 ions/cm 2 ) irradiations of uranium dioxide films on the YSZ substrates were shown to form the lattice damage only with partial destruction of the long range ordering.3

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Section: Introductionmentioning

confidence: 99%

XPS Study of Ion Irradiated and Unirradiated UO₂ Thin Films

et al. 2016

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“…Moreover, Table 1 presents also UO 2 solubility values obtained from literature in order to compare it to our data. 6,24,39,43 . However, we believe that in our work the thermodynamic equilibrium of the UO 2 dissolution was not achieved due to their composition of grains and grain boundaries.…”

Section: Uranium Solubility and Dissolution Ratementioning

confidence: 99%

“…The majority of these radionuclides is trapped in the UO 2 matrix and the only credible mechanism of their migration into the environment is dissolution and transport by water in contact with the spent fuel. In this case, the releasing rate of these radionuclides is governed by the dissolution rate of the UO 2 matrix 6 .…”

Section: Introductionmentioning

confidence: 99%

Radiolytic Corrosion of Uranium Dioxide: Role of Molecular Species

et al. 2014

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“…In Synroc-C, for example, zirconolite is designed to be the primary host phase for actinides, perovskite is the host phase for Sr and hollandite is the host phase for Cs. Synroc in its various forms is perhaps the most studied ceramic waste form to date, with numerous reports and publications on the processing conditions, crystal chemistry, element partitioning, aqueous durability and radiation damage effects (Ringwood et al, 1988;Smith et al, 1992;Vance, 1994;Lumpkin, 2001Lumpkin, , 2006Begg, 2003).…”

Section: Waste Forms Drive Natural Analogue Studiesmentioning

confidence: 99%

“…To gain a perspective on the state of play~20 years ago, readers interested in spent fuel and natural analogues thereof are referred to the collection of articles published in the Journal of Nuclear Materials, 190, 1À348 and the December 1994 issue of the MRS Bulletin, XIX (e.g. Forsyth and Werme, 1992;Shoesmith and Sunder, 1992;Janeszec and Ewing, 1992;Isobe et al, 1992;Johnson and Werme, 1994). These special issues also contain several interesting articles on nuclear waste glasses (e.g.…”

Section: Introductionmentioning

confidence: 99%

The role of Th-U minerals in assessing the performance of nuclear waste forms

et al. 2014

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Materials designed for nuclear waste disposal include a range of ceramics, glass ceramics and glass waste forms. Those with crystalline phases have provided the momentum for studies of minerals as a means to understand aspects of waste-form crystal chemistry, behaviour in aqueous systems and radiation damage over geological periods of time. Although the utility of natural analogue studies varies, depending upon the degree of analogy to the proposed geological repository and other factors such as chemical composition, the available data suggest that Th-U host phases such as brannerite, monazite, pyrochlore, zircon and zirconolite are resistant generally to dissolution in aqueous fluids at low temperatures. Geochemical durability may or may not extend to hydrothermal systems depending on the specifics of fluid composition, temperature and pressure. At elevated temperatures, for example, davidite may break down to new phase assemblages including titanite, ilmenite and rutile. Perovskite is generally less resistant to dissolution at low temperatures and breaks down to TiO2, releasing A-site cations to the aqueous fluid. Studies of radiation damage indicate that the oxide and silicate phases become amorphous as a result of the gradual accumulation of alpha-recoil collision cascades. Monazite tends to remain crystalline on geological time scales, a very attractive property that potentially eliminates major changes in physical properties such as density and volume, thereby reducing the potential for cracking, which is a major concern for zircon. In spite of recent success in describing the behaviour of Th-U minerals in geological systems, considerable work remains in order to understand the P-T-X conditions during alteration and T-t history of the host rocks. ABSTRACTMaterials designed for nuclear waste disposal include a range of ceramics, glass ceramics and glass waste forms. Those with crystalline phases have provided the momentum for studies of minerals as a means to understand aspects of waste-form crystal chemistry, behaviour in aqueous systems and radiation damage over geological periods of time. Although the utility of natural analogue studies varies, depending upon the degree of analogy to the proposed geological repository and other factors such as chemical composition, the available data suggest that Th-U host phases such as brannerite, monazite, pyrochlore, zircon and zirconolite are resistant generally to dissolution in aqueous fluids at low temperatures. Geochemical durability may or may not extend to hydrothermal systems depending on the specifics of fluid composition, temperature and pressure. At elevated temperatures, for example, davidite may break down to new phase assemblages including titanite, ilmenite and rutile. Perovskite is generally less resistant to dissolution at low temperatures and breaks down to TiO 2 , releasing A-site cations to the aqueous fluid. Studies of radiation damage indicate that the oxide and silicate phases become amorphous as a result of the gradual accumulation of...

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The prediction of nuclear fuel (UO2) dissolution rates under waste disposal conditions

Cited by 117 publications

References 26 publications

XPS Study of Ion Irradiated and Unirradiated UO₂ Thin Films

XPS Study of Ion Irradiated and Unirradiated UO₂ Thin Films

Radiolytic Corrosion of Uranium Dioxide: Role of Molecular Species

The role of Th-U minerals in assessing the performance of nuclear waste forms

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The prediction of nuclear fuel (UO2) dissolution rates under waste disposal conditions

Cited by 117 publications

References 26 publications

XPS Study of Ion Irradiated and Unirradiated UO2 Thin Films

XPS Study of Ion Irradiated and Unirradiated UO2 Thin Films

Radiolytic Corrosion of Uranium Dioxide: Role of Molecular Species

The role of Th-U minerals in assessing the performance of nuclear waste forms

Contact Info

Product

Resources

About

XPS Study of Ion Irradiated and Unirradiated UO₂ Thin Films

XPS Study of Ion Irradiated and Unirradiated UO₂ Thin Films