THEREDA: Thermodynamic reference database
In order to be able to make predictions about the safety of repositories, scientists and researchers carry out complex calculations. For example, they are interested in how a host rock evolves or how a future ice age might influence the repository. Eventually, the main concern here is the possible release of radionuclides from the waste packages in a repository and their transport into the biosphere.
Various data help the researchers to try and attempt estimating the mobility of contaminants. One difficulty in this respect lies in the acquisition of these data. Often, they are taken from various different sources (e.g. literature, commercial modelling codes) without any prior verification. This can lead to a lacking comparability of the results.
Objectives of the project
In order to generate results that are more easily comparable, the joint THEREDA – Thermodynamic Reference Database – project was initiated in 2006. The main objective of THEREDA is the creation of a comprehensive, internally consistent thermodynamic reference database for geochemical modelling, with the work focusing on the special conditions in the near-field of a repository for radioactive waste in Germany.
The thermodynamic data allow estimates regarding the solubility of contaminants and thus conclusions with regard to their mobilisation potential.
GRS is conducting this project together with the most important research institutions active in the field of radioactive and hazardous chemical waste disposal. The parties involved next to GRS are:
- KIT Institute for Nuclear Waste Disposal (KIT-INE) at the Karlsruhe Research Centre
- Helmholtz-Zentrum Dresden-Rossendorf Institute of Resource Ecology (HZDR-IRE)
- Technische Universität Bergakademie Freiberg Faculty Institute of Inorganic Chemistry (TU-BAF)
- Laboratory for Waste Management of the Nuclear Energy and Safety Research Division of Paul-Scherrer-Institut (PSI-LES)
The project is currently sponsored by BGE, the German federal company for radioactive waste disposal. It is now already in its fourth phase, which ends in 2025.
Provision, utilisation and character of the data
The thermodynamic data are provided and maintained by the joint project partners via the Internet. The users can also retrieve the data from the Internet. The intended circle of users includes above all government ministries, repository operators, universities and research institutes as well as communes where repositories are planned or under construction.
The THEREDA group provides ready-to-use parameter files online on their website; these can be used with four different widely-used calculation codes. Here, the responsibilities for the different data are shared out amongst the competences of the different institutions taking part in the joint project.
THEREDA has established itself in the international professional public in recent years. Exchanges exist among others with the Sandia National Laboratories (SNL) and the Los Alamos National Laboratories (LANL).
Quality and origin of the data
Apart from the promotion of the application of the data and the contact between users and experts, one particular goal of the integrated project partners is to document the origin of the data. Furthermore, the data are assessed as to their quality and subjected to an internally agreed control system.