No abstract

In 2009, ONDRAF/NIRAS, the Belgian Agency for Radioactive Waste and Enriched Fissile Materials, established a six-year research, development and demonstration (RD&D) programme to explore the feasibility of its concept for the geological disposal of Category B and C radioactive waste in Belgium. This programme, generally referred to as the ‘B&C Techno project’, aims to acquire evidence and build arguments in order to demonstrate that the proposed disposal system can be constructed, operated and progressively closed, taking into account long-term safety requirements and operational safety requirements.Galson Sciences Ltd (GSL) has been supporting the co-ordination of the activities involved in this project. This support has included synthesis of research outputs, and the development of various tools and methods to demonstrate that the Belgian geological disposal concept is feasible to implement. Two examples of studies conducted by GSL for ONDRAF/NIRAS as part of the B&C Techno project to substantiate feasibility are described in this paper: A review of other national geological disposal concepts to identify transferable experience relating to the feasibility of constructing, and assembling comparable disposal system components.Development of a storyboard illustrating the different steps involved in disposing of Category B and C waste.

When SCK CEN launched an RD&D programme on geological disposal in the 1970s, it was not certain if a deep geological repository (DGR) could be constructed in poorly indurated clay. This was tested by constructing the HADES underground research laboratory (URL) in Boom Clay, 225 m below SCK CEN's site in Mol. The construction history of the URL reflects how the understanding of the Boom Clay increased and how the excavation techniques and design of the gallery lining improved. It demonstrated that shafts, galleries and crossings between galleries can be constructed using industrial techniques. It also allowed to characterize the hydromechanical response of the clay and the clay disturbances induced by the excavation. This increased understanding is also reflected in the evolution of the geological disposal concept considered in Belgium. The current disposal concept foresees the installation of seals in the shafts and galleries. The HADES URL also offered the opportunity to test possible seal designs and develop a better understanding of the behaviour of bentonite, a possible seal material due to its swelling capacity, under in situ conditions.