Evaluation of uncertainty associated with parameters for long-term safety assessments of geological disposal

Yamaguchi, Tetsuji; Minase, Naofumi; Iida, Yoshihisa; Tanaka, Tadao; Nakayama, Shinichi

JAERI-Conf 2005-007, p.150 - 155, 2005/08

http://jolissrch-inter.tokai-sc.jaea.go.jp/pdfdata/JAERI-Conf-2005-007.pdf

no abstracts in English

Models of Cement-Water Interaction of Associated Thermodynamic Datand North America

D.Savag*; K.Lemke*; Sasamoto, Hiroshi; Shibata, Masahiro; Randolp*; Yui, Mikazu

JNC-TN8400 2000-004, 30 Pages, 2000/01

JNC-TN8400-2000-004.pdf:1.26MB

Modeling approaches that have been proposed for cement-water system are reviewed in this report, and relevant supporting thsrmodynamic data are compiled. The thermodynamic data include standard molal thermodynamic properties of minerals and related compounds comprising cements, and equilibrium constants for associated hydrolysis reactions. Similar data for minerals that are stable in hyperalkaline geologic environments (e.g., zeolites) are also included because these minerals could be formed as hyperalkaline fluids emanating from cementitious matelials in a repository for radioactive wastes interact with the surrounding host rock. Standard molal properties (i.e., standard molal Gibbs free energies and enthalpies of formation and standard molal entropies), and/or equilibrium constants for associated hydrolysis reactions, are included for. (1)cement minerals and related compounds (Reardon, 1992; Glasser et al., 1999) (2)calcium-silicate hydrate minerals (Sarkar et al., 1982), and (3)zeolites (calorimetric and estimated values from various sources) All these data are accepted at face value, and it is therefore cautioned that the data, considered as a whole, may not be internally consistent. It is also important to note that the accuracy of these data have not been evaluated in the present study. Several models appropriate for cement-water systems have been proposed in recent years. Most are similar in the sense that they represent empirical fits to laboratory data for the CSH gel-water system, and therefore not thermodynamically defensible. An alternative modeling approach based on thermodynamic principles of solid-solution behavior appropriate for CSH gel has recently been proposed, however. It is reviewed in the present study, and evaluated in relation to experimental results obtained by JNC on cement-water interactions. The solid-solution model is based upon a thermodynamically- and structually-justifiable description of CSH gel in terms of a non-ideal ...

Development of Thermodynamic Databases for Geochemial Calculations

Oda, Chie; Arthur, R. C.*; Sasamoto, Hiroshi; Shibata, Masahiro; Yui, Mikazu; Neyama, Atsushi*

JNC-TN8400 99-079, 287 Pages, 1999/09

JNC-TN8400-99-079.pdf:9.78MB

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, SPRONS.JNC, 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 1000C. 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 (25C) 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. SPRONS.JNC extends similar databases described elsewhere by incorporating new and revised data published in the peer-reviewed literature since 1991. The other database, PHREEQE.JNC, is compatible with the PHREEQE series of geochemical modeling codes. It includes equilibrium constants at 25C 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 100C at 1 bar. All equilibrium constants, reaction enthalpies, and logK(T) coefficients in PHREEQE.JNC are calculated usig SUPCRT and SPRONS.JNC, 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 ...

Thermodynamic Date for Predicting Concentrations of AnO and AnO Species in Geologic Environments

Choppin, G. R.*; Bronikowski, M.*; Chen, J.*; Byegard, J.*; Rai, D.*; Yui, Mikazu

JNC-TN8400 99-012, 155 Pages, 1999/01

JNC-TN8400-99-012.pdf:5.53MB

This report provides thermodynamic data for predicting concentrations of pentavalent and hexavalent actinide species (AnO and AnO) in geologic environments, and contributes to an integration of the JNC chemical thermodynamic database, JNC-TDB (previously PNC-TDB), for the performance analysis of geological isolation system for high-level radioactive wastes. Thermodynamic data for the formation of complexes or compounds with hydroxide, chloride, fluoride, carbonate, nitrate, sulfate and phosphate are discussed in this report. The estimation of the stability constants by use of the Born equation is included. The Pitzer parameters for AnO and AnO, redox potentials and equilibrium constants of redox reactions for actinides are also included.

Thermodynamic Date for Predicting Concentrations of Pu(III), Am(III), and Cm(III) in Geologic Environments

Rai, D.*; Rao, L.*; Weger, H. T.*; GREGORY R.CHOPPI*; Yui, Mikazu

JNC-TN8400 99-010, 95 Pages, 1999/01

JNC-TN8400-99-010.pdf:3.88MB

This report provides thermodynamic data for predicting concentrations of Pu(III), Am(III), and Cm(III) in geologic environments, and contributes to an integration of the JNC chemical thermodynamic database, JNC-TDB (previously PNC-TDB), for the performance analysis of geological isolation system for high-level radioactive wastes. Thermodynamic data for the formation of complexes or compounds with hydroxide, chloride, fluoride, carbonate, nitrate, sulfate and phosphate are discussed in this report. Where data for specific actinide(III) species are lacking, the data were selected based on chemical analogy to other trivalent actinides. In this study, the Pitzer ion-interaction model is mainly used to extrapolate thermodynamic constants to zero ionic strength at 25C.

Consideration on thermodynamic data for predicting solubility and chemical species of elements in groundwater, 1; Tc, U, Am

Yamaguchi, Tetsuji; Takeda, Seiji

JAERI-Data/Code 99-001, 74 Pages, 1999/01

JAERI-Data-Code-99-001.pdf:2.65MB

no abstracts in English

Progress in TRU chemistry; TRU chemistry for geologic disposal

Nakayama, Shinichi

KURRI-KR-17, p.1 - 14, 1997/00

no abstracts in English

None

Shibutani, Sanae; Yui, Mikazu

PNC-TN8100 96-008, 376 Pages, 1996/07

PNC-TN8100-96-008.pdf:25.96MB

no abstracts in English

None

Mihara, Morihiro; Yoshikawa, Hideki; Yui, Mikazu

PNC-TN8410 94-241, 53 Pages, 1994/07

PNC-TN8410-94-241.pdf:1.34MB

None

Cesium chemisorption behavior onto structural material under severe accident conditions, 4; Synthesis of cesium silicates

Takai, Toshihide; Takada, Juntaro; Nakajima, Kunihisa; Furukawa, Tomohiro; Osaka, Masahiko

no journal, , 

Fundamental knowledge of the characteristics of the Cs-chemisorbed deposits was important for decommissioning of the Fukushima-Daiichi Nuclear Power Plant (1F). Some important information was obtained from foregoing experiments results. Nevertheless, it was not enough for covering 1F accident conditions. Purpose of this study was to confirm the Cs-chemisorption mechanism in a wider range of temperature and atmosphere. Synthesis results of Cesium silicates, which was expected to form under a severe accident, was described in this presentation.