Geochemical modeling (EQ3/6) plan: Office of Civilian Radioactive Waste Management Program

This plan replaces an earlier plan for the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. It includes activities for all repository projects in the Office of Geologic Repositories: NNWSI, the Basalt Waste Isolation Project, the Salt Repository Project, and the Crystalline Project. Each of these projects is part of the Office of Civilian Radioactive Waste Management (OCRWM) Program. The scope of work for fiscal years 1986 to 1992 includes the work required to upgrade the geochemical codes and supporting data bases, to permit modeling of chemical processes associated with nuclear waste repositories in four geological environments: tuff, salt, basalt, and crystalline rock. Planned tasks include theoretical studies and code development to take account of the effects of precipitation kinetics, sorption, solid solutions, glass/water interactions, variable gas fugacities, and simple mass transport. Recent progress has been made in the ability of the codes to account for precipitation kinetics, highly-saline solutions, and solid solutions. Transition state theory was re-examined resulting in new insights that will provide the foundation for further improvements necessary to model chemical kinetics. Currently there is an increased effort that is concentrated on the supporting data base. For aqueous species and solid phases, specific to nuclear waste, requisite thermodynamic values reported in the literature are being evaluated and for cases where essential data is lacking, laboratory measurements will be carried out. Significant modifications and expansions have been made to the data base. During FY86, the total number of species in the data base has almost doubled and many improvements have been made with regard to consistency, organization, user applications, and documentation. Two Ridge computers using a RISC implementation of UNIX were installed; they are completely dedicated EQ3/6 machines.

[1]  D. L. Peck,et al.  The concept of electron activity and its relation to redox potentials in aqueous geochemical systems , 1984 .

[2]  R. A. Konynenburg.  Radiation chemical effects in experiments to study the reaction of glass in an environment of gamma-irradiated air, groundwater, and tuff , 1986 .

[3]  A. Lasaga,et al.  Kinetics of geochemical processes , 1981 .

[4]  Wolery,et al.  EQ3NR: a computer program for geochemical aqueous speciation-solubility calculations. User`s guide and documentation , 1983 .

[5]  J. Hostettler.  Electrode electrons, aqueous electrons, and redox potentials in natural waters , 1984 .

[6]  Kenneth S. Pitzer,et al.  Thermodynamics of electrolytes. I. Theoretical basis and general equations , 1973 .

[7]  J. Peisl,et al.  Diffuse X-ray scattering from neutron irradiated crystalline quartz , 1982 .

[8]  R. Berman,et al.  Heat capacity of minerals in the system Na2O-K2O-CaO-MgO-FeO-Fe2O3-Al2O3-SiO2-TiO2-H2O-CO2: representation, estimation, and high temperature extrapolation , 1985 .

[9]  C. Baes,et al.  Review of information on the radiation chemistry of materials around waste canisters in salt and assessment of the need for additional experimental information , 1980 .

[10]  J. Delany.  Reaction of Topopah Spring tuff with J-13 water: a geochemical modeling approach using the EQ3/6 reaction path code , 1985 .

[11]  R. Garrels,et al.  A chemical model for sea water at 25 degrees C and one atmosphere total pressure , 1962 .

[12]  R. Robinson,et al.  Ionic hydration and activity in electrolyte solutions. , 1948, Journal of the American Chemical Society.

[13]  T. J. Wolery,et al.  Precipitation kinetics option for the EQ6 geochemical reaction path code , 1986 .

[14]  David L. Parkhurst,et al.  BALANCE : a computer program for calculating mass transfer for geochemical reactions in ground water , 1982 .

[15]  B. Wood,et al.  Rates of Hydrothermal Reactions , 1983, Science.

[16]  H. Helgeson,et al.  Summary and critique of the thermodynamic properties of rock forming minerals , 1978 .

[17]  Kenneth S. Pitzer,et al.  Thermodynamics of electrolytes. V. effects of higher-order electrostatic terms , 1975 .

[18]  H. Helgeson.  Complexing and Hydrothermal Ore Deposition. , 1964 .

[19]  R. A. Van Konynenburg.  Radiation doses in granite around emplacement holes in the Spent Fuel Test - Climax. Final report , 1984 .

[20]  K. Knauss,et al.  Dependence of albite dissolution kinetics on ph and time at 25°c and 70°c , 1986 .

[21]  T. J. Wolery,et al.  Fixed-fugacity option for the EQ6 geochemical reaction path code , 1984 .

[22]  Thomas A. Jones,et al.  Calculation of mass transfer in geochemical processes involving aqueous solutions , 1970 .

[23]  W. E. Glassley,et al.  Reference waste package environment report , 1986 .

[24]  D. A. Sverjensky.  The distribution of divalent trace elements between sulfides, oxides, silicates and hydrothermal solutions: I. Thermodynamic basis , 1985 .

[25]  W. C. Graustein,et al.  Radium, thorium and radioactive lead isotopes in groundwaters: application to the in situ determination of adsorption-desorption rate constants and retardation factors , 1982 .

[26]  Ivars Neretnieks,et al.  Diffusion in the rock matrix: An important factor in radionuclide retardation? , 1980 .

[27]  W. B. Durham,et al.  The effect of gamma irradiation on the strength and elasticity of climax stock and westerly granites , 1986 .

[28]  Thomas J. Wolery,et al.  Extension of the EQ3/6 Computer Codes to Geochemical Modeling of Brines , 1984 .

[29]  R. Garrels,et al.  Evaluation of irreversible reactions in geochemical processes involving minerals and aqueous solutions—II. Applications , 1969 .

[30]  D. Sverjensky.  Prediction of Gibbs free energies of calcite-type carbonates and the equilibrium distribution of trace elements between carbonates and aqueous solutions , 1984 .

[31]  Susan Werner Kieffer,et al.  Thermodynamics and Lattice Vibrations of Minerals, 4, Application to Chain and Sheet Silicates and Orthosilicates (Paper 80R1044) , 1980 .

[32]  R. Garrels,et al.  Solutions, Minerals and Equilibria , 1965 .

[33]  V. Oversby.  Important radionuclides in high level nuclear waste disposal: Determination using a comparison of the U.S. EPA and NRC regulations , 1987 .

[34]  H. Walther,et al.  Speciation of actinide ions in aqueous solution by laser-induced pulsed photoacoustic spectroscopy , 1984 .

[35]  Susan Werner Kieffer,et al.  Thermodynamics and Lattice Vibrations of Minerals, 2, Vibrational Characteristics of Silicates (Paper 8R1054) , 1979 .

[36]  H. Helgeson,et al.  Thermodynamics of hydrothermal systems at elevated temperatures and pressures , 1969 .

[37]  Susan Werner Kieffer,et al.  Thermodynamics and lattice vibrations of minerals: 3. Lattice dynamics and an approximation for minerals with application to simple substances and framework silicates , 1979 .

[38]  Peter C. Lichtner,et al.  Continuum model for simultaneous chemical reactions and mass transport in hydrothermal systems , 1985 .

[39]  James W. Ball,et al.  A Comparison of Computerized Chemical Models for Equilibrium Calculations in Aqueous Systems , 1979 .

[40]  K. J. Jackson,et al.  EQ3/6: status and applications , 1984 .

[41]  Susan Werner Kieffer,et al.  Thermodynamics and lattice vibrations of minerals: 1. Mineral heat capacities and their relationships to simple lattice vibrational models , 1979 .

[42]  T. J. Wolery,et al.  Calculation of chemical equilibrium between aqueous solution and minerals: the EQ3/6 software package. [In FORTRAN extended 4. 6 for CDC6600 and 7600] , 1979 .