THEREDA (Thermodynamic Reference Data Base) is a collaborative project whose goal is to establish a comprehensive and internally consistent thermodynamic reference data base for geochemical model calculations of aqueous electrolyte solutions up to high concentrations. This is essential for near- and far-field processes in different rock formations, which are discussed as potential repositories for radioactive and chemo-toxic waste in Germany and other countries.
THEREDA provides thermodynamic data and Pitzer interaction coefficients for aqueous solutions. Coupled to appropriate codes, this allows the calculation of solubilities of radiotoxic and chemo-toxic elements. Here we follow the approach of the OECD-NEA thermochemical database. Currently, for the host rock salt, THEREDA represents the only database in the world that polythermally covers the entire system of oceanic salts, including acids and bases.
Our work focuses on critically evaluating and providing data that support the calculation of solubilities in highly concentrated saline solutions, such as those that may occur in rock salt or various clay formations. Data from the NEA database will be adjusted or supplemented as needed. In particular, Pitzer interaction coefficients consistent with standard thermodynamic data provided in THEREDA will be added.
In contrast to the very restrictive quality requirements of the OECD NEA database, we also provide lower quality data when needed to calculate experimentally confirmed solubility data. A classification by the source, quality, and type of primary experimental data from which the input thermodynamic data were derived has been developed to guide THEREDA users.
The internal data structure of THEREDA is kept decidedly flexible, paving the way for future extensions of the database, e.g., for other potential host rocks or contaminants. All work on THEREDA is performed decentrally via a web interface to the database. Compliance with quality requirements and internal data consistency is ensured by control mechanisms embedded in the database. Comprehensive documentation of the data accompanies the web interface.
THEREDA was and is planned, implemented and further developed jointly by established research institutions conducting research in the field of radioactive waste disposal and potential host rocks. THEREDA partners are open to cooperation with other institutions from Germany and abroad that are active in a similar field. Questions about the possibilities of an associated partnership with THEREDA can be addressed to the project coordinator Helge Moog or to all other project partners.
The THEREDA website was migrated to a new content management system. Unfortunately, the user's passwords could not be transferred in this process. Therefore, all registered users have to use the Forgot your password function to select a password.
The Application examples section has been completely revised. You are invited to inspect the application examples. The number of systems for which application examples are provided is continuously being extended.
With the new THEREDA Journal we are going to establish a new kind of documentation more visible to our users. It is intended primarly for the documentation of data selections in THEREDA.
The THEREDA management board announces a new data release. The main difference to the last release is the addition of a thermodynamic model for plumbous lead. Complexes of lead with chloride, sulphate, and hydroxide are explicitly accounted for in this model. The presented data set for plumbous lead is valid for 298.15K only.
The complete release has been extensively tested in 296 test cases including more than 1400 numerical results for the following codes:
- Geochemist's Workbench
As in the former release we also offer a JSON-formatted version.
Due to the increasing complexity of the database it is possible to run calculations for systems for which THEREDA isn't qualified. Therefore, users are advised, to have a look on our continously growing list of application examples.
If you want to read more on THEREDA or cite the THEREDA database in your publications, you can use these references:
- Moog, H.C.; Bok, F.; Marquardt, C.M.; Brendler, V. (2015) "Disposal of nuclear waste in host rock formations featuring high-saline solutions – Implementation of a thermodynamic reference database (THEREDA)", Appl. Geochem., 55, 72–84.
- Altmaier, M., Kienzler, B.; Marquardt, C.M.; Neck, V.; Brendler, V.; Richter, A.; Hagemann, S.; Herbert, H.-J.; Moog, H.C.; Voigt, W.; Wilhelm, S. (2008) "THEREDA: Ein Beitrag zur Langzeitsicherheit von Endlagem nuklearer und nichtnuklearer Abfälle" (transl.: "THEREDA: A Contribution to Long-term Safety of Repositories of Nuclear and Non-nuclear Wastes") Atw. Internationale Zeitschrift für Kernenergie 53(4), 249–253.
THEREDA is funded by BGE – the federal company for radio-active waste disposal, with the contract number 45181017.