Stress factor human activities
Authors: Eckhardt Anne 
Published: November 2021

Abstract. Activities of future humans can influence the safety of a closed repository. The German safety requirements for a final repository for high-level radioactive waste (EndlSiAnfV, 2020) therefore stipulate that developments induced by future human activities which may become relevant for the safety of the repository system must be taken into account when optimising the repository system and verifying its robustness. The focus here is on inadvertent human intrusion into the repository. Developments that can be induced by present human activities serve as reference developments. Dealing with future human activities is challenging. The uncertainties about anthropogenic developments taking place in the 1 million-year assessment period are overwhelming and can hardly be reduced. Moreover, knowledge about human activities in the future cannot be empirically verified, so that it becomes difficult to differentiate between knowledge and mere opinion (Grunwald, 2007, p. 57). Developments in future human activities are the subject of futures research. In the interdisciplinary experiment “Stress factor human activities”, it was therefore investigated whether findings can be derived from futurology sources that might be useful for optimising the repository system and verifying its robustness. Based on potential impacts on the sealed repository, drivers and trends, future narratives, findings and ideas from technical literature and science fiction as well as experiences in the field of radioactive waste management, 25 scenarios of future human activities that may influence the safety of a repository were derived. The spectrum of scenarios ranges from “drift into failure” in uses of the geological subsurface to attacks targeting the repository. It includes biological, chemical and physical impacts on the repository. In addition to direct impacts, those that occur slowly and possibly unnoticed are also addressed. From today's point of view, climate change and the endeavour to open up new reserves of raw materials and energy are important drivers. The distinction between intended and unintended activities is often not clear-cut. The experiment confirms that scenario development is ridden with prerequisites and is necessarily interdisciplinary. Different methodological approaches have to be combined, prerequisites and assumptions have to be clearly identified. Due to the limited time horizon of futures research, it is necessary to continually adapt and update scenarios of future human activities in the sense of a “learning process” with new findings and developments. Although many details remain speculative, scenarios provide a differentiated picture of human activities that may influence the safety of the final repository from the current perspective. Patterns are emerging that indicate how human activities could be incorporated into the optimisation of a repository and the verification of its robustness. The results of the interdisciplinary study “Stress factor human activities” therefore lead to the conclusion that futures research can contribute to optimising the long-term safety of a final repository (Eckhardt, 2021).