Uranium and plutonium equilibriums in aqueous solutions to 200.degree.C

Lemire, Robert J.; Tremaine, Peter R.

doi:10.1021/je60087a026

Cited by 145 publications

(68 citation statements)

References 27 publications

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“…Site studies indicate that coprecipitation of trace metals in secondary minerals controls the concentrations of these dissolved constituents (Linklater et al 1994). Lemire and Tremaine (1980) Pu(.HP04), Lemire and Tremaine (1980) P-%o3 Lemire and Tremaine (1980) PuO,(OH) (a) Lemire andTremaine (1980) PuF3 Lemire andTremaine (1980) PuO,(OH), Lemire and Tremaine (1 980) Pu(OH)4 Lemire and Tremaine (1980) . Pu0,HP04 Lemire and Tremaine (1 980) PUo2 Lemire and Tremaine (1980) where a is the capacity factor or ratio of the moles per unit volume of water-saturated solid, C,, to the moles per unit volume of liquid, C,.…”

Section: C432 Maqarin Area In Northern Jordanmentioning

confidence: 99%

“…Lemire and Tremaine (1980) Pu(.HP04), Lemire and Tremaine (1980) P-%o3 Lemire and Tremaine (1980) PuO,(OH) (a) Lemire andTremaine (1980) PuF3 Lemire andTremaine (1980) PuO,(OH), Lemire and Tremaine (1 980) Pu(OH)4 Lemire and Tremaine (1980) . Pu0,HP04 Lemire and Tremaine (1 980) PUo2 Lemire and Tremaine (1980) where a is the capacity factor or ratio of the moles per unit volume of water-saturated solid, C,, to the moles per unit volume of liquid, C,. The capacity factor is related to the K, by the equation where p is the dry bulk density of the porous media and K, is the amount of contaminant adsorbed per unit mass of porous = solid divided by the amount of contaminant per unit volume of liquid.…”

Section: C432 Maqarin Area In Northern Jordanmentioning

confidence: 99%

See 1 more Smart Citation

Effects on radionuclide concentrations by cement/ground-water interactions in support of performance assessment of low-level radioactive waste disposal facilities

Krupka¹,

Serne²

1998

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C o p k r o f h b r t r y~m d r t n d v d r u n d h 8~m m r h t h . N R C~~r AbstractThe U.S. Nuclear Regulatory Commission (NRC) is developing a technical position document that provides guidance regarding the performance assessment of low-level radioactive waste (LLW) disposal facilities. This guidance includes considerations associated with the chemical environment of the vault disposal system and the effects this system may have on the release and mobility of radionuclides. Because the disposal system will contain cementitious materials as structural, waste form, andor bacld'ill materials, the geochemical properties of pore waters buffered by reactions with cement will be very different from those waters associated with the local soil and geology. This environment therefore needs to be considered within the source term calculations if credit is taken for solubility limits andor distribution coefficients for -dissolved radionuclide concentrqtions within disposal units. Geochemical modeling may be used to assess potential chemical conditions in concrete vault disposal units and associated effects on aqueous speciation, solubilities, and sorption of radionuclides that are released from the waste form.In support of NRC7s development of this technical position, two literature reviews were done on information related to the chemical environments associated with the interaction of water with cementitious materials. One review was conducted on methods and associated solid-phase assemblages used to model the composition of pore water resulting from reaction with cementitious materials used in a disposal vault. This literature review also included related information on experimental studies of cemendwater systems, natural analogue studies of cement and concrete, and radionuclide solubilities experimentally determined in cement pore fluids.Based on the results of .this review, geochemical modeling was used to demonstrate the calculation of conservative maximum concentrations for dissolved americium, neptunium, nickel, plutonium, radium, strontium, thorium, and uranium with respect to key geochemical input parameters for two ground-water environments associated with the disposal system. These environments include 1) a cement buffered system, wherein the leachate pH is controlled at values above 10 by the effective buffering capacity of the concrete; and 2) a ground-water buffered system, wherein the leachate pH and related solution parameters are dominated by the local ground-water system.Another literature review was completed on the available data for the sorption potential of selected LLW radionuclides onto "fresh" cement/concretewhere the expected pH of the cement pore waters will equal or exceed 10. The review included data for the radionuclides americium, inorganic carbon, chlorine, iodine, lanthanide elements, niobium, nickel, neptunium, plutonium, radium, strontium, technetium, thorium, and uranium. Based on information gleaned from the literature, a database was developed of preferred minimum distribution coeff...

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Section: C432 Maqarin Area In Northern Jordanmentioning

confidence: 99%

Section: C432 Maqarin Area In Northern Jordanmentioning

confidence: 99%

Effects on radionuclide concentrations by cement/ground-water interactions in support of performance assessment of low-level radioactive waste disposal facilities

Krupka¹,

Serne²

1998

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“…Several databases of thermodynamic properties of the actinides have been developed over the last three decades. Of historical importance are the compilations and reviews of Lemire and Tremaine (1980), Phillips et al (1988), andFuger et al (1990). The most recent comprehensive and consistent databases have been based on compilations produced by the Nuclear Energy Agency (NEA) for plutonium and neptunium (Lemire et al, 2001), americium , uranium (Grenthe et al, 1992) and technetium (Rard et al, 1999).…”

Section: Aqueous Speciation and Solubilitymentioning

confidence: 99%

Environmental Geochemistry of Radioactive Contamination

Siegel

Bryan

2003

Treatise on Geochemistry

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This report attempts to describe the geochemical foundations of the behavior of radionuclides in the environment. The information is obtained and applied in three interacting spheres of inquiry and analysis: 1) experimental studies and theoretical calculations, 2) field studies of contaminated and natural analog sites and 3) model predictions of radionuclide behavior in remediation and waste disposal. Analyses of the risks from radioactive contamination require estimation of the rates of release and dispersion of the radionuclides through potential exposure pathways. These processes are controlled by solubility, speciation, sorption, and colloidal transport, which are strong functions of the compositions of the groundwater and geomedia as well as the atomic structure of the radionuclides.The chemistry of the fission products is relatively simple compared to the actinides. Because of their relatively short half-lives, fission products account for a large fraction of the radioactivity in nuclear waste for the first several hundred years but do not represent a long-term hazard in the environment. The chemistry of the longer-lived actinides is complex; however, some trends in their behavior can be described. Actinide elements of a given oxidation state have either similar or systematically varying chemical properties due to similarities in ionic size, coordination number, valence, and electron structure. In dilute aqueous systems at neutral to basic pH, the dominant actinide species are hydroxy-and carbonato-complexes, and the solubility-limiting solid phases are commonly oxides, hydroxides or carbonates. In general, actinide sorption will decrease in the presence of ligands that complex with the radionuclide; sorption of the (IV) species of actinides (Np, Pu, U) is generally greater than of the (V) species.The geochemistry of key radionuclides in three different environments is described in this report. These include: 1) low ionic strength reducing waters from crystalline rocks at nuclear waste research 4 sites in Sweden; 2) oxic water from the J-13 well at Yucca Mountain, Nevada, the site of a proposed repository for high level nuclear waste (HLW) in tuffaceous rocks; and 3) reference brines associated with the Waste Isolation Pilot Plant (WIPP). The transport behaviors of radionuclides associated with the Chernobyl reactor accident and the Oklo Natural Reactor are described. These examples span wide temporal and spatial scales and include the rapid geochemical and physical processes important to nuclear reactor accidents or industrial discharges as well as the slower processes important to the geologic disposal of nuclear waste.Application of geochemical information to remediating or assessing the risk posed by radioactive contamination is the final subject of this report. After radioactive source terms have been removed, large volumes of soil and water with low but potentially hazardous levels of contamination may remain. For poorly-sorbing radionuclides, capture of contaminated water and removal of radi...

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“…Literature review identified only one source of higher temperature complex stability data for plutonium species (Lemire and Tremaine 1980). The data used in this report was derived from their work using theoretical calculations instead of actual measurements.…”

Section: Temperature Effectsmentioning

confidence: 99%

“…Sparse empirical data is found on the tank environment and only theoretical estimates are found of the thermodynamic data needed to calculate the effects of temperature, using known chemical constructs that rely on enthalpy and heat-capacity measurements. Using the estimation technique presented by Lemire and Tremaine (1980), the solubility for amorphous Pu(IV) oxidehydroxide would not be significantly affected by temperatures up to 100°C. Required thermodynamic data for even the simple system, Pu-OH-H,O, is not precisely known and is essentially nonexistent for complex systems, such as Pu-OH-C0,-H,O.…”

Section: Effects Of Other Parameters On Plutonium Solubilitymentioning

confidence: 99%