// Site Investigation and Assessment

MODERN

Monitoring developments for safe repository operation and staged closure

Within the project, a structured approach – the “Monitoring Workflow” – was elaborated to provide a generic methodology for the development and implementation of a monitoring programme that considers specific national boundary conditions. The workflow allows the linking of high-level monitoring objectives to the detailed selection of monitoring technologies and sensor placements. The specific objective was to propose and evaluate a parameter evaluation and feasibility screening scheme that allows the design of a (practical) monitoring plan that links monitoring objectives with the specific features and needs of a particular disposal concept and the corresponding safety case. For generic repository concepts in salt (Germany), clay, and granite host rock, monitoring plans were therefore developed. The idea behind this was to describe how a monitoring system could look like based on current technology and to identify possibilities and limitations of repository monitoring. Additionally, a case study was performed to provide an analytical and practical evaluation of the feasibility detecting possible alternative repository evolutions by means of a monitoring system in facilities for the deep geological disposal of radioactive waste. An assessment of the technical feasibility was performed to get an idea of how monitoring systems should be designed in practice, how to evaluate the possibility to detect failures of sensors in case access to the sensors is no longer possible, and how to discuss the possibility to detect whether the repository evolution is as predicted, i.e. is in line with the “reference evolution scenario”. Or whether a different route is followed, i.e. an “alternative evolution scenario”.