Excavation of the first five final disposal tunnels at Finland’s Onkalo used nuclear fuel disposal facility has been completed, Finnish waste management company of Posiva has said. The total length of the tunnels is about 1700 metres. Mining started at the beginning of May 2021.

According to programme manager Kimmo Kemppainen, the completion of the excavation is an important milestone in the progress of the work on the final disposal facility. “Now the construction of the final disposal tunnels continues with the strengthening of the tunnels and levelling of the tunnel floor,” he said.

The last section of the now excavated disposal tunnels was detonated on 18 June, and the end of the tunnel was completed for the start of the next work phases on 21 June. The excavation contractor was YIT Suomi Oy, which has been excavating tunnels for Posiva for several years. Holes for approximately 180 disposal capsules will be drilled in the first five disposal tunnels.

Image: Excavation of the first tunnel at Finland's Onkalo nuclear fuel disposal facility is now complete (photo courtesy of Posiva)