Uranium solubility

The 2003 ACGIH threshold limit value-time-weighted average (TLV-TWA) for uranium (soluble and insoluble compounds, as U) is 0.2 mg/m with a short-term excursion limit (STEL) of 0.6mg/mk... 

Goodwin, B. W. "Maximum Total Uranium Solubility Under Conditions Expected in a Nuclear Waste Vault, TR-29, Atomic Energy of Canada Limited, Pinawa, Manitoba, Canada, 1980. 

Uranium solubility is increased even more in the nitrate microcosms, and one possible explanation is the conversion of acetate to CO2, coupled with nitrate reduction, which would give higher dissolved carbonate concentrations in the nitrate microcosms. However, PHREEQE modelling showed that the higher CO concentration would not greatly affect uranium speciation in solution and is therefore unlikely to account for the enhanced solubility. Alternatively, as nitrate is reduced to ammonium (NH/), which promotes cation exchange, this could lead to displacement of U02 from surface complexes, which are the predominant uranyl species on mineral surfaces. " ... 

The results of the test showed that the uranium dioxide produced a vigorous reaction with the nitrate melt, beginning at approximately 400°C. At this time the melt was open to the atmosphere, and no nitric acid was being added. Nitrogen dioxide was evolved as a gaseous product of the reaction, but there was no visual indication of any uranium solubility in the molten nitrate eutectic. Complete reaction, indicated by the cessation of gas evolution, required approximately 2.5 hours at 500°C. 

Finneran, K. T., Housewright, M. E., and Lovley, D. R. (2002b). Multiple influences of nitrate on uranium solubility during bioremediation of uranium-contaminated subsurface sediments. Environ. Microbiol. 4, 510-516. 

URANIUM, SOLUBLE and INSOLUBLE COMPOUNDS (as Uranium) (Soluble and insoluble uranium compounds have variable molecular formulas and variable formula weights. The molecular formula for uranium is U. The formula weight for uranium is 238.00). 

Factors that may influence the solubility of uranium in a hydro-thermal system are temperature, pressure, oxidation state, pH, activity of complexing anions and partial pressure of such volatile components as carbon dioxide. The solubility of uranium decreases with increase in temperature, so cooling cannot be a possible mechanism of deposition. The effect of pressure on uranium solubility is difficult to evaluate, but at the relatively, low pressures of formation for many hydrothermal deposits the role of pressure is to affect the partial pressure of volatile components only. As pressure decreases, the partial pressure of CO2 decreases, which will decrease the activity of... 

URANIUM. SOLUBLE COMPOUNDS (ASU) u Synonyms vary depending upon specific compound Uranyl nitrates combustibles. Uranium hexa-nuoride water Properties vary depending upon specific compound ... 

The fuel described in the previous paragraph is the clean fuel which would be charged initially. During reactor operation, however, fission products will build up in the fuel and would be maintained at a level dictated by the economics of the chemical reprocessing system used. It has been found that the fission products and other additives to the bismuth have an important effect on the solubility of uranium in bismuth. These have lieen carefully investigated in order to permit selection of reactor temperatures that will ensure that all the uranium remains in solution during reactor operation. Likewise, the solubility of steel corrosion products has been investigated to determine their effect on uranium solubility in bismuth. 

Solubilities of combination of elements in bismuth. The effect of Zr on the U solubility. The mutual solubilities of uranium and zirconium in bismuth have been measured over the temperature range 325 to 700 C. The data are plotted in Fig. 20-5. When bismuth is saturated with zirconium, the uranium solubility is appreciably decreased. On the other... 

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