First blast for Onkalo fired just over 20 years ago
There are still several people working at Posiva who remember the start of the construction of ONKALO® 20 years ago, almost to the date. The first blast for an open cut excavation at the mouth of the present day ONKALO tunnel was fired on 22 September 2004.
Posiva’s Construction Manager Kimmo Kemppainen was in attendance when the first round of the tunnel was blasted.
First, holes were bored and charged and then covered with rubber mats before the blast was fired. We started with fairly small blasts. At first, we we advanced only in three-meter intervals in a phased manner, Kemppainen recalls.
In addition to Kemppainen, at least four other people still employed by Posiva worked for the company at the time. They are Johanna Hansen, who now works as an expert in clay performance and characterisation, Director of Development Petteri Vuorio, Senior Advisor Kimmo Lehto, Field Manager Janne Laihonen, Operation Construction Manager Kimmo Lehtola and Equipment Technician Aimo Hiironen.
The usual consensus in Olkiluoto is that the first blast was fired on the site by the then Minister of Industry Sinikka Mönkäre (SDP). However, Kemppainen can tell a more detailed version of the story.
The official launch event of ONKALO construction took place much earlier in the summer, complete with festivities and the Minister. And at this event, Minister Mönkäre only exploded a bag of cement. This created an impressively dusty launch blast, Kemppainen reveals.
Since that first blast, Posiva has excavated its historically significant way down to the bedrock towards the actual start of the final disposal of spent fuel. The encapsulation plant has been completed above ground, as well. In late August, Posiva started the Trial Run of Final Disposal at the facility.
In the Trial Run, the operation of the final disposal facility is tested comprehensively, albeit still without the spent fuel. The facility features many unique systems and equipment produced as a result of decades of research and now used together for the first time. The Trial Run of Final Disposal can be described as a joint functional test of all the systems and equipment. The Trial Run will take several months.
Text: Pasi Tuohimaa
Photos: Kimmo Kemppainen