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ThermoChimie is a thermodynamic database created and developed by Andra (French National Radioactive Waste Management Agency) for more than 25 years (1995). In October 2014, Nuclear Waste Services (formerly Radioactive Waste Management Limited, UK) joined the project and the “ThermoChimie consortium” was formed. In March 2018, Ondraf/Niras (National Agency for Radioactive Waste Management, Belgium) also joined the “ThermoChimie consortium”. Data acquisition is supported by an experimental program, in addition to active literature survey and the development of predictive models.


ThermoChimie addresses geochemical modelling and performance assessment tasks for French geological repositories for radioactive waste. The key criteria determining data included in the ThermoChimie database are self-consistency, exhaustiveness and traceability. Its domain of application is mainly within a pH range of 6 to 13, Eh of -0.5V to +0.5V and for temperatures below 80°C.

The database contains source references for each selected equilibrium constant. However, there is no detailed documentation concerning the selection process of individual equilibrium constants.


There is online access to the latest version of the database and to some general documentation.