A kinetic study of the dissolution of uraninite

Grandstaff, David E.

doi:10.2113/gsecongeo.71.8.1493

Cited by 175 publications

(93 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The reaction order with respect to O 2 is 1 in the kinetic treatment while the proposed mechanism implies a reaction order of 0.5. It should be noted that there are experimental studies showing a reaction order of 1 as well as 0.5 with respect to O 2 [38,[48][49][50]. In general, the reaction order decreases with increasing O 2 concentration [50].…”

Section: Oxidation Of Uo 2 (S)mentioning

confidence: 99%

“…Oxidative UO 2 dissolution rates under various conditions have been reported in numerous publications [4,5,7,9,10,13,14,[21][22][23][30][31][32][33][34][35]44,48,50,53,54]. The studies considered here were all performed at room [7,10,34,44].…”

Section: Dissolution Of Oxidized Uo 2 (S)mentioning

confidence: 99%

“…The UO 2 materials used were powders, with particle size ranging from ~1 μm to ~1 mm, UO 2 discs or pellets. For comparison, one study in which natural pegmatic uraninite (UO 2 content 75.5 wt-%) was used [48], has been included.…”

Section: Dissolution Of Oxidized Uo 2 (S)mentioning

confidence: 99%

See 2 more Smart Citations

Oxidation of UO2(s) in aqueous solution

Roth

Jönsson

2008

Open Chemistry

View full text Add to dashboard Cite

Abstract:In this review the kinetics and mechanism of oxidative dissolution of UO 2 (s), mainly under conditions of relevance for the safety assessment of a deep geological repository for spent nuclear fuel, are discussed. Rate constants for the elementary processes involved (oxidation of UO 2 and dissolution of oxidized UO 2 ) are used to calculate the rates of oxidative UO 2 (s) dissolution under various conditions (type of oxidant, oxidant concentration and HCO 3 -/CO 3 2-concentration) for which experimental data are also available. The calculated rates are compared to the corresponding experimental values under the assumption that the experimental numbers reflect the steady-state conditions of the system. The agreement between the calculated rates and the corresponding experimental ones is very good, in particular for the higher rates. In general, the calculated rates are somewhat higher than the experimental numbers. This can be due partly to the use of initial concentrations rather than steady-state concentrations in the calculations. The kinetic data are also used to quantitatively discuss the dynamics of spent nuclear fuel dissolution under deep geological repository conditions. © Versita Warsaw and Springer-Verlag Berlin Heidelberg.

show abstract

Section: Oxidation Of Uo 2 (S)mentioning

confidence: 99%

Section: Dissolution Of Oxidized Uo 2 (S)mentioning

confidence: 99%

See 1 more Smart Citation

Oxidation of UO2(s) in aqueous solution

Roth

Jönsson

2008

Open Chemistry

View full text Add to dashboard Cite

show abstract

“…Much information has recentiy come to light pertaining to the nature of mechanisms and rate laws (See for example Aagaard and Helgeson, 1982;Bemer, 1978Bemer, ,1980Bemer, ,1981Bemer and Holdren, 1979;Blum and Lasaga, 1991;CarrollWebb and Walther, 1988;WoUast, 1984,1985;Holdren and Bemer, 1979; Fun-er and Grandstaff, 1976Grandstaff, ,1977Grandstaff, , 1978; Helgeson, Murphy, and Aagaard., 1984;Wolery, 1986,1988;Lasaga, 1981ab;Murphy andHelgeson, 1987,1989;PeO:ovich, 1976; Petrovich, Bemer, and Goldhaber., 1976;Rimstidt and Barnes, 1980;Schott, Bemer, and Sjoberg, 1981;Tahnan and Nesbitt, 1988;WoUast and Chou, 1985;Wood and Walther, 1983;Zinder, Furrer, and Stumm, 1986). Kinetic reaction path modeling has only become a possibility due to the recent availability of quantitative descriptions of the rates of some geochemically important reactions.…”

Section: Reaction Pathsmentioning

confidence: 99%

EQ6, a computer program for reaction path modeling of aqueous geochemical systems: Theoretical manual, user`s guide, and related documentation (Version 7.0); Part 4

Wolery¹,

Daveler²

1992

224

179

View full text Add to dashboard Cite

“…An increase in the release was quantified as a function of increasing bicarbonate concentration. Bicarbonate-promoted dissolution has been observed with numerous uranium minerals including uranophane (Casas et al 1997b;Perez et al 2000), soddyite (Perez et al 1997;Casas et al 1997b), uraninite (Casas et al 1998;Casas et al 1994;Pierce et al 2005;Grandstaff 1976;de Pablo et al 1999), becquerelite (Casas et al 1997a;Sowder et al 2000b;Hering and Schnoor 2000), and autunite-group minerals (Sowder et al 2000b). Casas et al (Perez et al 2000;Casas et al 1997b) quantified the solubility of uranophane through a series of static tests and provide a solubility constant of log K o so = 11.7 ± 0.6.…”

Section: Dissolution Kinetics Of Uranophanementioning

confidence: 99%

DNA Profile Analysis and Interpretation

2014

DNA Analysis for Missing Person Identification in Mass Fatalities

View full text Add to dashboard Cite

SummaryThe Hanford Site is a former nuclear defense production facility. A groundwater plume containing uranium, originating from a combination of purposeful discharges of wastewater to cribs, trenches, and ponds, along with some accidental leaks and spills related to nuclear fuel fabrication activities, has persisted beneath the Hanford Site 300 Area for many years. Despite the cessation of uranium releases and the removal of shallow vadose zone source materials, the remedial action objective to lower the concentration of groundwater uranium to the U. S. Environmental Protection Agency maximum contaminant level concentration of 30 µg/L has not been achieved within the anticipated 10-year time period. Some unknown amount of contamination remains in the vadose zone beneath the lower extent of the excavation activities. Additional contamination also may remain beneath buildings and facilities in the southern portion of the 300 Area, which has not been decontaminated and decommissioned. The use of polyphosphate technology for source treatment in the vadose zone and capillary fringe is expected to accelerate the natural attenuation of uranium to thermodynamically stable uranium-phosphate minerals. This effort will complement the current 300 Area treatability test being conducted within the saturated zone (e.g., 300 Area aquifer) for in situ treatment of uranium-contaminated groundwater.Polyphosphate technology has been demonstrated for in situ precipitation of phosphate phases to control the long-term fate of uranium. A critical component of the development and testing is detailed evaluation to determine if polyphosphate technology could be modified for infiltration from ground surface or some depth of excavation to stabilize source uranium phases. This report presents results from bench-scale treatability studies conducted under site-specific conditions to optimize the polyphosphate amendment for implementation of a field-scale technology demonstration to stabilize uranium within the 300 Area vadose zone and capillary fringe of the Hanford Site. Documented in this report are data related to 1) the retardation of polyphosphate as a function of water content and pore water velocity, 2) the reaction between uranium-bearing solid phases and aqueous polyphosphate remediation technology as a function of polyphosphate composition and concentration, 3) the mechanism of autunite formation via the reaction of solid-phase calcite-bound uranium and aqueous polyphosphate remediation technology, 4) the transformation mechanism and reaction kinetics between uranyl-carbonate and -silicate minerals with the polyphosphate remedy under advective conditions, and 5) the extent and rate of uranium released and immobilized as a function of polyphosphate composition and the infiltration rate of the polyphosphate remedy. Kinetic rate law parameters were determined from single-pass flow-through experiments. Pressurized unsaturated flow tests were used to determine the effect of polyphosphate composition, concentration, and infiltration rate...

show abstract

A kinetic study of the dissolution of uraninite

Cited by 175 publications

References 0 publications

Oxidation of UO2(s) in aqueous solution

Oxidation of UO2(s) in aqueous solution

EQ6, a computer program for reaction path modeling of aqueous geochemical systems: Theoretical manual, user`s guide, and related documentation (Version 7.0); Part 4

DNA Profile Analysis and Interpretation

Contact Info

Product

Resources

About