So we have the Onkalo entrance here. Here we started the excavation in 2004.
Yes, it's a bit foggy because of the moist air outside and the cool inside.
Okay, good. So we have here this location for identification. You can see the numbers
and everyone is identified here and also the car.
So the system knows who are inside and down there, and which cars.
So it's very good for safety. If something is happening, there is online information
of who are here working or visiting inside these facilities.
Okay, and here you can see these green signs on the right wall, and they are metres from
the entrance.
So it's now like half a kilometre from the entrance and because this is dipping in 1 to
10 approximately, you have metres below the ground surface when you divide this number
by 10.
So when we have driven one kilometre along this tunnel, we are 100 metres deep inside
the bedrock.
Are you excavating by blasting?
Yes, drill and blast. But these vertical shafts, they are raise bored.
Without any kind of support for the tunnel?
You mean the raise boring?
Yeah.
Yeah, it's -- I mean, the shafts are bored as 100-metre sections. And we are driving
like in a spiral down there, and in every loop, we are driving like one kilometre and 100
metres deeper.
And for every loop, there has been raise boring for these shafts, and then excavation
of this access tunnel 100 metres deeper, and then again raise boring of the shafts.
But the waste rock from the raise boring is also loaded along this tunnel up.
So basically all the rock that you excavate will be re-used here?
Not all the rock, but a big part of it. I mean, because we will backfill the --
In the meantime, you’re just storing it somewhere?
Yeah. But the repository facilities, I mean the actual repository disposal tunnels, we
will backfill with bentonite. So not all the volume we are excavating here --
This tunnel, this part will be filled in with the original rock that you excavated?
Yeah. But it is mixed with bentonite, I guess.
Also the part that will be here?
Yeah.
In this tunnel?
Yes. And actual disposal tunnels and central tunnels and down to the repository facilities
just by backfilling with bentonite.
Where is the bentonite coming from?
Now, in the testing development phase it's coming from several locations. It is commercial
material we can buy in from several sites around the world.
So there are several options but we are still testing what would be the best.
How deep are we now?
We are now soon on the -300-metre level. And it's again a level where we have access tunnels
to the vertical shafts. So here we have these tunnel crossings now. And access tunnels to
shafts here.
We have two shafts for ventilation, and one shaft for personnel elevator. And now we don't
have elevator ready. We have only this security basket. But in the coming years, in the near
future, we will build a real elevator in the personnel shaft.
Now, when did you start digging here for this tunnel?
2004.
2004? So it's 10 years, more than 10 years digging.
Yeah, actually we reached the repository level in 2010. So it took like 6 years. But after
reaching the repository level, we have continued the excavation of other facilities.
So in the first years, it was kind of a simple task to just excavate this access ramp. But
now, in the last years, we have excavated some technical facilities, facilities for testing and
demonstration of our methods and machines down there at the repository level.
Now we are coming to the repository level, and this is one example
of specific rooms or facilities excavated for specific investigation projects.
We have a couple of these kinds of rooms, and for different kind of investigations like
rock mechanics, small scale hydrogeology. Here we are studying the retention properties
of the rock.
We have several drill holes, drilled from this room, different directions. And we can
test the retention properties of the rock by tracer elements. We can test it one single
hole and between holes and study the different nuclides, how they are moving inside the rock.
Yes, here on the left side, we have our demonstration facilities. We can visit there later, but
first visit here in the deeper part. We call these technical facilities, underground openings
for several different purposes.
Actually this is very interesting site; on the right side, we have a drilling site. And
we have drilled here a 300-metre long sub-horizontal drill hole.
And it is located in a place where we will continue the excavation of the tunnel and where
will be access tunnel to the first disposal panel. So first set of disposal panels will
be located some hundreds metres from here.
Now, it's some weeks ago, the drilling was ready and now we are doing different kind
of measurements. Measurements of hydrogeology, geophysics.
We have also the sample core from this hole on our facilities on the ground surface, and
now we are studying the samples there.
No, not here, there’s some work going on. I guess we can't visit there.
But we can go here to the largest room we have here. In the future it is for several
purposes, like parking cars and other vehicles, and some other purposes.
This is a 140-metre long hole, and 15 metres wide. It is pretty large.
And now, we will use these kinds of facilities for different purposes, but when these are
excavated, we can use them for collecting geological and other data.
For example, here this floor was carefully cleaned and all the fractures were mapped,
very detailed, and the rock types and everything. So it's a pretty unique set of geological data
we can collect here.
And it is then helping us to predict the rock properties for planning and constructing the
actual repository facilities.