Rock characterization ahead and around tunnels, with focus on safety assessment, is instrumental for rock engineering and mining operations.
Posiva Oy is constructing a deep rock storage for final disposal of spent nuclear fuel at Olkiluoto, Finland. As the excavation progresses, R&D activities are conducted in the ONKALO facility, focusing on predictions of the bedrock and groundwater conditions of the site, during construction and after completion.
In Sweden, SKB carries out R&D work for detailed rock characterization at the Äspö Hard Rock Laboratory (HRL), the final repository for spent nuclear fuel being actually planned to be built at Forsmark.
Knowledge about existing network of fractures is important for the safety and feasibility of a final spent nuclear fuel repository.
Methodological advances and procedures developed in this environment can be of interest for other tunneling and mining applications.
With detailed 3D tunnel investigations novel acquisition tools, measuring routines, processing techniques and interpretation approaches needed to be developed and put to test:
The studies at ONKALO and the Äspö Hard Rock Laboratory (HRL) were primarily meant to: