The final disposal of high-level radioactive nuclear waste is primarily about safety. Safety analyses are thus essential in the repository search, its operation, and decommissioning as well as after the emplacement of radioactive waste. The safety analyses are to take place three times during the site selection process. They will become more detailed, more complex, and thus more meaningful with each phase. In order to be able to make increasingly precise statements in the course of the procedure, codes for numerical models are being developed; with these calculations, various processes in a repository system can be simulated and evaluated.
In order to ensure that all analyses can be viewed and used publicly, the BGE relies on freely accessible software. Together with the Helmholtz Centre for Environmental Research (UFZ) and the Freiberg University of Mining and Technology (TUBAF), an open source code is being developed for conducting preliminary safety analyses and maintaining a safety case for a repository for high-level radioactive waste. The project will run from July 2021 to the end of December 2024. The funding volume amounts to €4.96 million.
The research project is called OpenWorkFlow
With the special software developed in this way, all processes in and around a repository are to be modelled and, if possible, quantified. Because safety must be estimated over a period of one million years, the model statements are used as one element for evaluation. This applies to all three different host rocks (clay, crystalline, and salt); the BGE must make statements about these for the preliminary safety analyses. The model calculations can also be used to check whether the requirements and criteria from the Repository Site Selection Act and the safety ordinances are met.
The aim of the research project “OpenWorkFlow” is to develop a well-documented, quality-assured, freely accessible (Open Source) synthesis platform for safety analyses as part of the site selection process. It is planned to continue to use these for the safety demonstration for the repository following the site selection procedure. The project is initially scheduled to run until 2024 but is projected to continue until 2031. The basis for the work is the already established and widely used open source software OpenGeoSys (OGS) (external link).
Transparency through accessibility
The BGE works as transparently as possible in the site selection process. The software it uses for the safety analyses thus contains freely-available source code and extensive documentation. From the perspective of the BGE, the “OpenWorkFlow” project is one of the lighthouse projects in the site selection process. Not only because it runs over a long period of time but also because it gives the interested public a glimpse into the workshop of the BGE. The project aims to develop a work flow that can map all aspects to be considered when analysing the repository system and thus lead to new basic knowledge and improved reliability of statements on the safety of a repository.
