Implementing Geological Disposal of Radioactive Waste Technology Platform

Explanation of the contents of the activity

1. Building on studies undertaken in the past decades (which have been particularly focused on the long-term safety issues) the work should include:
   • To start with checking the available information on operational safety from existing facilities in operation or under construction (e.g. in WIPP, Konrad and ONKALO, and in all underground research facilities);
   • Then to evaluate where interchange with other industries might be possible (for example the mining industry and the more recent work of the carbon capture and sequestration industries, noting that mining and tunnelling requirements might by very different);
   • And to develop common databases and/or information exchange forums (for example for initiating events, accessing standard procedures and for reporting and sharing data relating to deviations such as frequency of failure of various types of equipment).
   • Example of additional development and demonstration:
     Ventilation in an underground construction is always challenging. It becomes more challenging when “nuclear facility”-type ventilation is required. Strategies for ventilation (single or dual) and their demonstration need to be developed for all types of geological repositories.

2. Developing strategies and evaluating the impact on long-term safety, design, complexity and cost of geological repositories for specific operational issues.

   This contributes to planning the design approach. The discussion of assumptions and approaches in handling operations, ventilation and radiation controlled areas vs. non-radiation controlled areas. They are factors influencing the design, layout and costs.

   The requirement is a better understanding of the benefits and disadvantages with regard to safety, cost, logistics and technical difficulty of different design strategies such as transport underground (e.g. drift vs. shaft), vault designs( tunnels, small vaults, large vaults etc.), package emplacement strategies (e.g. remote, semi-remote, manual, by row or column), and ventilation (continuous, local, natural). These issues are all important for helping to demonstrate ALARP through the design process.

   For example, strategies to evaluate operational issues such as emergency plans, gaseous radionuclides and their impacts on workers and the environment during the operational phase. Explosive gases, air dust, ventilation and fire fighting strategies are certainly of interest to various WMOs.

   Example :

   Concrete support for disposal drifts in clay environment: besides the design of concrete supports there is a need to proceed to demonstration of digging large drifts and installing the supports. The long term behaviour of the concrete in such an environment, and especially its consequences on the long-term safety should be assessed (qualitatively)