JNC TN840G 99-079 JP005525? Development of Thermodynamic Databases for Geochemical Calculations September , 1999 Tokai Works 33003064 Japan Nuclear Cycle Development Institute tz£l>a T31U-1194 ^^f-BKWfPil&ft^fttiU - 3 3 Inquiries about copyright and reproduction should be addrev,ed to Technical Information Section, Administration Division, Tokai Works, Japan Nuclear Cycle Development Institute 4-113 Muramatsu, Tahai-mura, Naha-gun, Ibaraki-fcen, 319-11114, Japan FT'R*14-H--t ^ 't^^P;^ i Japan Nuclear Cycle Development Institute' 19HH PLEASE BE AWARE THAT ALL OF THE MISSING PAGES IN THIS DOCUMENT WERE ORIGINALLY BLANK JNCTN8 400 99-079 September,1999 Development ofThermodynamic Databases for Geochemical Calculations Randolph C Arthur", Hiroshi Sasamoto2', Masahiro Shibata21 Mikazu Yui2>, Atsushi Neyama31 Abstract Two thermodynamic databases for geochemical calculations supporting research and development on geological disposal concepts for high level radioactive waste are described in this report. One, SPRONSJNC, is compatible with thermodynamic relations comprising the SUPCRT model and software, which permits calculation of the standard molal and partial molal thermodynamic properties of minerals, gases, aqueous species and reactions from 1 to 5000 bars and 0 to lOOO'C. This database includes standard molal Gibbs free energies and enthalpies of formation, standard molal entropies and volumes, and Maier-Kelly heat capacity coefficients at the reference pressure (1 bar) and temperature (25^) for 195 minerals and 16 gases. It also includes standard partial molal Gibbs free energies and enthalpies of formation, standard partial molal entropies, and Helgeson, Kirkham and Flowers (HKF) equation-of-state coefficients at the reference pressure and temperature for 1147 inorganic and organic aqueous ions and complexes. SPRONSJNC extends similar databases described elsewhere by incorporating new and revised data published in the peer-reviewed literature since 1991. The other database, PHREEQEJNC, is compatible with the PHREEQE series of geochemical modeling codes. It includes equilibrium constants at 25^ and 1 bar for mineral-dissolution, gas- solubility, aqueous-association and oxidation-reduction reactions. Reaction enthalpies, or coefficients in an empirical log K(T) function, are also included in this database, which permits calculation of equilibrium constants between 0 and 100*0 at 1 bar. All equilibrium constants, reaction enthalpies, and log K(T) coefficients in PHREEQEJNC are calculated using SUPCRT and SPRONSJNC, which ensures that these two databases are mutually consistent. They are also internally consistent insofar as all the data are compatible with basic thermodynamic definitions and functional relations in the SUPCRT model, and because primary experimental and field observations that constrain these data are consistently evaluated JNCTN8400 99-079 within this modeling framework. The accuracy of the data in SPRONS.JNC is evaluated in the present study and elsewhere by comparison of calculated equilibrium constants with their experimental counterparts at pressures and temperatures that span much of the subcritical and supercritical regions of H2O stability. Additional experimental investigation of mineral solubilities and aqueous reactions, particularly between 0 and lOO'C, are needed to further assess, and refine if necessary, the reliability of these databases. Field studies on phase equilibria in near-surface geological environments may be useful for this purpose because associated reaction times are greater than can be accommodated experimentally. The effects on mineral-solution equilibria of metastability and solid solution, and differences in the crystallinity and state of order/disorder in minerals, must be determined, however, before reliable thermodynamic properties can be retrieved from field investigations. 1) Monitor Scientific, L.L.C*., Denver, Colorado, US A*(formerly QuantiSci Inc) 2) Japan Nuclear Cycle Development Institute, Tokai Works, Japan 3) Computer Software Development Corp., Tokyo, Japan JNC TN8400 99-079 19 9 9^9/! tz Of Randolph C Arthur", fcii H SFRONSJNC -^^-^[i, SUPCRT 7 7 CLtfct), SUPCRT V : 1-5000 bars, S£: o-ioocc) SPRONS.JNC ii, 195 16 , 2513, lbar Maier-KeUy ^^i i tz SPRONS.JNC , 25*0, lbar .> h n tf-is i tf Helgeson-Kkkham-Howers (HKF) SPRONS.JNC fi, 1991 , PHREEQE.JNC T*^> 19 , i f fPHREEQEj tffiV'Sit ^ T- ^ S ^73^r- 9 ^- 7,Xh 5 0 PHREEQE.JNC (i, bar ^^#T^<7?¥»^®:*SiiLTV^0 $^ PHREEQE.JNC T*(i, 0~ 10013, lbar^ (bgK) PHREEQE.JNC iZ$ %>&$ttni£X\±, SUPCRT V7 h -7x7*3 i ^ SPRONS.JNC PHREEQRJNC t SPRONS.JNC t±, Wl—<W& SUPCRT JNCTN8400 99-079 SPRONSJNC iz- ^"^li, #tc 0 1) Monitor Scientific, L.L.C*., Denver, Colorado USA *(formerly QuantiSci Inc) 2) JNCTN8 400 99-079 TABLE OF CONTENTS Page 1 Introduction 1 2 Objectives 4 3 Status of Thermodynamic Databases 7 3.1 Database Requirements 7 3.1.1 Internal consistency 7 3.1.2 Experimental basis 8 3.1.3 Documentation 9 3.1.4 Verification of accuracy 9 3.2 Internally Consistent Databases for Minerals, Gases and Aqueous Species 10 3.2.1 SUPCRT 10 3.3 Internally Consistent Databases for Minerals 11 3.3.1 Berman (1988) 11 3.3.2 Holland and Powell (1990) 12 3.3.3 Gottschalk (1997) . 12 3.4 Other Internally Consistent Databases, and Data Compilations 13 3.5 Comparison of Reliable Thermodynamic Data for Minerals 13 3.6 Reliable Databases for Geochemical Calculations 18 3.6.1 Recommended databases 18 3.6.2 Databases not recommended 18 3.6.3 Development strategy 19 4 Thermodynamic Framework 20 4.1 Standard-State and Other Conventions 20 4.2 Thermodynamic Relations 23 4.2.1 Minerals and gases 23 4.2.1.1 Primary thermodynamic data for minerals and gases . 26 4.2.2 Aqueous species: Summary of the revised HKF model 26 4.2.2.1 Solvation contribution to the partial molal volume ... 27 4.2.2.2 Non-solvation contribution to the partial molal volume 29 4.2.2.3 Heat capacities of aqueous solutes 29 4.2.2.4 Apparent standard partial molal thermodynamic properties of aqueous ions and neutral species 31 4.2.2.5 Primary thermodynamic data for aqueous species .... 32 4.2.3 Reactions among minerals, gases and aqueous species 32 4.3 Retrieval of Thermodynamic Properties from Experimental Data .... 33 4.3.1 Reaction data .* 33 4.3.1.1 Phase-equilibrium experiments 34 4.3.1.2 Solubility experiments 36 4.3.2 Mineral and gas data 39 4.3.2.1 Standard molal heat capacities 39 4.3.2.2 Standard molal volumes 40 4.3.3 Electrolyte data 40 4.3.3.1 Partial molal volumes and heat capacities of aqueous electrolytes 41 4.3.3.2 Equation-of-state parameters for aqueous ions 42 4.3.4 Statistical/Mathematical Analyses 45 4.3.4.1 Properties 45 JNCTN8400 99-079 4.3.4.2 Reactions 47 4.3.4.3 Simultaneous evaluation of multiple reactions 50 4.4 Estimation of Thermodynamic Properties and Equation-of-State Parameters 52 4.4.1 Minerals 52 4.4.2 Aqueous solutes 55 Description of Thermodynamic Databases 70 5.1 Overview 70 5.2 SPRONSJNC 73 5.2.1 Description 73 5.2.2 Sources of unrevised data 74 5.2.3 Sources of new and revised data 76 5.2.4 Data for minerals not considered by Helgeson et al. (1978) ... 80 5.2.5 Conventional and non-conventional aqueous species 82 5.2.6 Consistency between JNC's core thermodynamic database and SPRONS.JNC 84 5.3 PHREEQE.JNC 87 5.3.1 Description 87 5.3.2 Redox reactions 89 5.3.3 Comparison of thermodynamic data in PHREEQE.JNC and the H3 TDB 90 5.3.4 Excluded reactions 98 Evaluation of Database Reliability 100 6.1 Gas Solubilities and Acid Dissociation Constants 101 6.2 System SiO2-H2O 102 6.2.1 Quartz 102 6.2.2 Amorphous silica 104 6.2.3 Chalcedony 104 6.2.4 Moganite 105 6.2.5 Aqueous speciation 105 6.3 System AI0O3-H2O 106 6.3.1 Gibbsite 106 6.3.2 Boehmite 107 6.3.3 Diaspore 108 6.3.4 Corundum 109 6.3.5 Aqueous speciation 109 6.4 System SiO2-Al->O3-H2O 110 6.4.1 Kaolinite 110 6.4.2 Kaolinite, boehmite, diaspore, andalusite, pyrophyllite 112 6.5 System Na^-^O-SiCvA^CV^O 113 6.5.1 K-feldspar, muscovite, quartz -. 115 6.5.2 Muscovite, andalusite, quartz 116 6.5.3 Muscovite, kaolinite 116 6.5.4 Muscovite, quartz, pyrophyllite 116 6.5.5 Albite, paragonite, kaolinite, pyrophyllite, andalusite, quartz 116 6.5.6 Albite 117 6.5.7 Analcime 117 6.6 System MgO-SiO2-H2O 118 6.6.1 Aqueous speciation 119 6.7 System CaO-SiO2-Al2O3-H2O 119 6.7.1 Aqueous speciation 120 6.8 System CaO-MgO-FeO-BaO-SrO-H2O-CO2 120 6.8.1 Aragonite and calcite 121 JNCTN8400 99-079 6.8.2 Strontianite 121 6.8.3 Witherke 121 6.8.4 Siderite 122 6.8.5 Aqueous speciation 122 6.9 System CaO-BaO-SrO-SO3-H2O 123 6.9.1 Anhydrite 123 6.9.2 Barite 123 6.9.3 Celestite 124 6.10 System FeO-S(rb)-H2O-HCl 124 6.10.1 Pyrite 124 6.10.2 Pyrrhotite 125 6.10.3 Magnetite 125 6.10.4 Aqueous speciation 126 6.11 Stability Relations Among Smectites, and the Solubility of Hike ... 126 6.11.1 Smectites 127 6.11.2 Hike 128 6.12 Aqueous Dissociation Reactions 130 6.13 Comments on Database Management 133 6.13.1 Internal consistency 133 6.13.2 Experimental basis 133 6.13.3 Documentation 135 6.13.4 Verification of accuracy 135 7 Acknowledgements 136 8 References 137 Appendix A: Listing of the SPRONS.JNC Database Appendix B: Listing of the PHREEQE.JNC Database Appendix C: Calculated and Experimental Equilibrium Constants of Mineral and Gas Solubility Reactions as Functions of Pressure and Temperature Appendix D: Calculated and Experimental Equilibrium Constants of Aqueous Reactions as Functions of Pressure and Temperature Appendix E: Calculation Examples JNCTN8400 99-079 1 Introduction The Japanese repository concept for permanent disposal of high-level nuclear wastes is based on an integrated system of natural and engineered barriers to radionuclide migration.