Welcome to THEREDA
The Thermodynamic Reference Database (THEREDA) is designed for geo-chemical models in the context of a radioactive waste repository. The primary focus is on the correct calculation of the solubilities of radionuclides, fission products and matrix elements (construction materials and mineral phases of the surrounding host rock).
THEREDA especially addresses high-salinity aqueous solutions (brines) and therefore supports the Pitzer ion-interaction approach. Great effort has been made to ensure the internal consistency of the data.
For the oceanic salt system, THEREDA is applicable in the temperature range from 0 to 110 °C, for some subsystems even beyond. As such, THEREDA is the only database in the world that polythermally covers the entire system of oceanic salts. The current radionuclide selection includes actinides (Th, U, Np, Pu, Am, Cm) and fission products (Se, Sr, Tc, Cs). The majority of the data for these radionuclides is valid for 25 °C.
THEREDA can export ready-to-use parameter files in the formats of commonly used geochemical codes: ChemApp, Geochemist's Workbench, PHREEQC, and ToughReact.
THEREDA's data set is regularly benchmarked by recalculating experimental measured values, with all results documented in the "Application examples" section.
Application examples
An extensive survey of all tested systems can be accessed using the menu item Application Examples.
Data release 2021
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
- PHREEQC
- TOUGHREACT
- CHEMAPP
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.
Key References
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.

Project Funding
THEREDA is funded by BGE – the federal company for radio-active waste disposal, with the contract number 45181017.