Methodical derivation of expected and deviating evolutions (scenario development) for a potential repository site

A safety case is a formal compilation of evidence, analyses and arguments that quantify and substantiate a claim that a repository will be safe. The description of the future evolution of a final repository system is a fundamental requirement for assessing its long-term safety and therewith part of the safety case. The deviation of future evolutions includes the analysis of relevant influencing factors and the uncertainties regarding the actual evolution of the final repository system.

The systematic determination of evolutions for a potential disposal site bases on a climatic and geological long-term forecast and a FEP catalogue (features, events and processes) for the respective site. For this purpose, the FEPs have to be classified according to their probability, their significance regarding their impact on safety functions, and based on regulatory requirements (FEP screening).

The objective of this project is the development of a comparable workflow for all host rocks and a rationale as to where this workflow must branch into different paths for various host rocks and emplacement concepts. Therefore, the project will focus on specific characteristics in the scenario development regarding the different host rocks and emplacement concepts. Subsequently, we plan to compile options for host rock specific standardizations for the methodology and to compare existing national and international workflows for the derivation of evolutions. The project therefore serves to harmonize scenario development in the course of the site selection process in Germany, pursuant to the Repository Site Selection Act (StandAG).