BMH Technology delivers a tunnel back-fill installation system to Posiva’s ONKALO® repository in Eurajoki, Finland

The underground final disposal tunnels in Olkiluoto bedrock will be filled with clay components to protect the final disposal canisters. The tunnels will be filled from the floor to the ceiling with a granule mixture that consists of bentonite pellets crushed to different sizes. The filling is executed with a tunnel back-fill installation system, which transfers and installs the granular material into the deposition tunnel (Posiva).

The system consists of a material transfer container, an above-ground receiving station with a screw pocket, material transfer equipment and an installation machine. BMH delivers the main equipment used for receiving and transferring the clay components from the ground level up until the installation machine.

"Co-operation with BMH has been fluent and open since the offer phase. BMH has taken a very proactive and innovative approach as a supplier, which has been extremely important in this pilot project that was based on only a partly defined concept", says Tero Hanhisalo, the project's initial project manager from Posiva.

At the above-ground receiving station, the granular material is released from a transfer container into a screw pocket from which it's conveyed into the transfer equipment. The transfer equipment, installed on an automatic guided vehicle (AGV) on wheels, conveys the granule mixture into the deposition tunnel and passes it onto the installation machine, which installs the material inside the tunnel.

In this project, the customer's quality requirements for both steel works and corrosion protection were extremely precise. Last week, Posiva's project team visited BMH Production to supervise a factory acceptance test (FAT) on the equipment. In the next phase, the system will undergo a site acceptance test (SAT).