1. The thermodynamic reference database for nuclear waste disposal in Germany
Helge C. Moog, H.-J. Herbert, V. Brendler, A. Richter, M. Altmaier, C. Marquardt, W. Voigt, S. Wilhelm

2. Precipitation / Dissolution
Context
Host Rock
Backfill
Surface Reactions
Redox Reactions
Complex Formation
Mikrobial Processes
Formation of Colloids
Radiolysis
Gas Generation
Precipitation / Dissolution
Thermodynamic
Equilibrium-
Modeling
Waste

3. What do we need to perform a thermodynamic equilibrium calculation?
Question:
How much UO2 gets
Dissolved at pH = 8?
Boundary Conditions
Code:
PHREEQC
GWB
CHEMAPP
EQ3/6 …
Parameterfile
Prone to errors
Lots of work!!!
Result
Thermodynamic Database
Modification of database
Agreement ?
Exp. Data

4. Basic idea
Thermodynamic calculations of various institutions become compareable, by creating parameter files from a common database.
Parameterfile 1
Daten.dat
Parameterfile 2
Daten.dat
Parameterfile 3
Daten.dat
Parameterfile 4
Daten.dat
Reference database

5. Thermodynamic Database
Thermodynamic equilibrium modeling for nuclear and non-nuclear waste disposal as a common task
Creation of a mutually agreed reference database
Long-term usability
Easy access via the world wide web
Easy applicability: Making available ready-to-use parameter files
Internal consistency
Comprehensiveness
Documentation
Parameter File
Exp. Data
Thermodynamic Database

6. Data structure: Phases and Phase constituents
Elements aq
Pu4+
4 Pu, -4 EA
PuO2+
1 Pu, 2 O, -1 EA
PuO2(CO3)35-
1 Pu, 11 O, 3 C, 5 EA

7. Data structure: Phase constituent types and Reactions
Primary Master
Pu4+
Secondary Master
PuO2+
PuO2(OH)(am)
PuO2(CO3)35-
Products
Reactand
Coefficient
Pu<4+> -1
H2O(l) -2
PuO2<2+> +1
H<+> +2
H2(g)
Reactand
Coefficient
PuO2<+> -1
H2O(l)
H<+> +1
PuO2(OH)(am)
Reactand
Coefficient
PuO2<+> -1
CO3<2->
PuO2(CO3)3<5-> 1

8. What do we mean by „thermodynamic database“?
Consistency of data
Cp0
DfG0
DfH0 S0
logK
logb
DrCp0
DrG0
DrH0
DrS0
DrG0(T)
„A technical framework which ensures that dependent and independent data are stored in a manner which ensures internal consistency when independent data are modified“
logK(T)

9. Internal calculations
DfG0
DfH0 S0
Gibbs-Helmholtz-relationship

10. Internal calculations
DfG0
logK
logb

11. Internal calculations
DfH0 S0
DrH0
DrS0

12. Internal calculations
logK
DrG0

13. Succession of internal calculations
DfG0
DfH0 S0
logK
DrG0
DrH0
DrS0
1/2

14. Technical Basics Datenbanksystem = PostgreSQL Relations: >79
Attributes: >854
Constraints: >120

15. Documentation Calculation Mode Category (Volker) m (Cl<->)
Class -1 F
Internally calculated R
By definition / convention fixed value 1
Value based upon experimental thermochemical data
Value based upon experimental equilibrium data in aqueous solution 2
Chemical analogue value, based upon thermochemical data
Chemical analogue value, based upon experimental equilibrium data in aqueous solution 3
Estimated value, based upon founded correlations and models for formation data
Estimated value, based upon founded correlations and models for reaction data 4 NA
Origin of value not reported; data class cannot be determined 5
Not consistent with other data in THEREDA 6
Data class not yet entered (to be done)
Quality -1
Internally calculated
By definition / convention fixed value 1
Reliable datum 2
Datum is reliable within the given range of error 3
Questionable value (uncertain model for speciation, uncertain auxiliary data) 4
Suitability for modelling or correctness not yet determined 5
Scrutinized and deemed inapplicable for modeling 6
Data quality not yet entered (to be done)
Source -1
Internally calculated
By definition / convention fixed value 1
…international review or from an internationally acknowledged review article 2
Value taken from an institutional review 3
Value is based upon a number of publicly accessible publications 4
Value is based upon a single publicly accessible publication 5
Value is based upon internal sources not available to the public 6
Data source not yet entered (to be done)
Category F
Formation data R
Reaction data FR
Based on formation- and reaction-type data NA
Not applicable
Calculation Mode
Category (Volker)
Class (Volker)
Source (Volker)
Quality (Volker)
Interaction Model (Pitzer, SIT, EDH, …)
Sets
Validities
Technical Papers (Volker) pH
m (Cl<->)

16. Technical Basics Web Server Internet Client Content Management System
Interface Modules
Content Management System
DBMS
Web Server
Client
Internet

17. How it is used THEREDA-DB Specification by the user: Elements
Interaction Model
Code
Gen. Datafile
Parameter File
GWB
PHREEQC
CHEMAPP
EQ3/6

18. Access via World Wide Web

19. Access via World Wide Web
Query is performed interactively with the user
Thermodynamic data and interaction coefficients
Presently, we are preparing the website to allow for the query of data, to be defined interactively by the user. This functionality will progressively be extended to allow for the download of groups of data and code-specific parameter files for geochemical calculation codes, such as PHREEQC, Geochemist's Workbench, or CHEMAPP.
generic format JSON: script language, simultaneous mapping of the input format for alternate calculation methods LMA (Law of Mass Action) and GEM (Gibbs Energy Minimization) ; JSON as independent output option which is independent from export filters 19

20. Access via World Wide Web
Phase constituents grouped by phases and oxidation number of central element
Thermodynamic data of pure elements
With [Show Data] display of detailed data 20

21. Access via World Wide Web
Export of data as CSV or MS-Excel©
Tool-Tips with additional information (formation reaction, classification of data, references) 21

22. Access via World Wide Web Compilation of complex datasets
Storage of md5-checksum of all downloaded parameter files
Benchmark calculations are documented, archived and made accessible to the user
Open and free-of-charge access to thermodynamic reference data

23. Additional element of quality assurance: feedback from the user
All pages in german AND ENGLISH

24. Comprehensiveness (in part)
196 Phases
312 aq. Species (incl. 34 Primary Master)
336 formation reactions
789 Standard data sets (Pitzer)
717 interactions (Pitzer and SIT)
Many Actinide data related to Volker

25. Current activities Preparation of first release of data for
System of ozeanic salts (for some subsystems up to 300°C)
Am, Cm, Nd
Completion (and test!) of export programs for
Geochemist‘s Workbench (GWB)
CHEMAPP
EQ3/6
PHREEQC
Execution and documentation of benchmark calculations

26. Planned activities in the near future
Creation for web-based user interface (primarly intended for editors)
Implementation of an internal review (to be tested with the first data to be released)
Preparation of the integration of sorption data
Release of data for Np und Pu planned ~ Sommer 2011

27. Thank you for your attention!