- There's an urban legend
that when grave-robbers
found their way to
ancient Egyptian tombs,
there were warnings they ignored.
"Do not open this tomb.
"Do not steal the riches inside.
"You will be cursed and you will die."
It's not true. Not just
the curses aren't real,
but those warnings were
just an urban legend.
The robbers wouldn't have
been able to read them.
And even if they could,
the messages weren't warning of curses.
They were just the ancient equivalent
of a 'no trespassing' sign.
This is Olkiluoto, an island
on the far west of Finland.
And here, they're building a tomb
for something that really is dangerous.
In a few years, the deep bedrock here
will contain the world's
first long-term storage site
for high-level nuclear waste,
right next to some of the
reactors that produce it.
This isn't a video about whether
nuclear power is good or bad.
I think it's good, and so,
it seems, does Finland.
The third reactor here is being tested now
and it's due to go online next year.
But this video is about
a different question.
We do have nuclear power in the world,
so where do we put the waste?
I didn't know how it would
feel until I stood here.
It is very strange to have 400 metres
of rock above my head
and knowing that inside that
solid plug of clay there
there is high-level radioactive waste.
This new tunnel complex is called Onkalo,
which translates as 'cavity'.
And long-term storage
really does mean long-term:
100,000 years.
To put that in perspective,
100,000 years ago, humans
hadn't made it to Europe yet;
the continent was still frozen
in the middle of an ice age.
Our species were just hunter-gatherers.
This facility is being designed
to last for geological time.
And yes, despite the fact
that there are hundreds of
nuclear reactors in the world,
right now there is no permanent
geologic storage facility anywhere
for high-level radioactive waste,
the spent nuclear fuel, the really nasty stuff
that could cause disasters if it leaks.
Now, the problem isn't urgent.
The world doesn't actually produce
that much of it, relatively speaking.
A century's worth of high-level waste
from all the current reactors in Finland
will fit in the final version
of this one new facility.
But right now, around the world,
high-level radioactive waste
is generally stored near reactors,
first in water ponds that
require active cooling,
and then in concrete casks that'll last,
well, about as long as a
concrete building would;
not long enough.
The US has been trying to work
out a storage site for years,
but their one serious
attempt, Yucca Mountain,
has been mired in politics for decades.
Finland, here, is closest
to building that solution.
- The geology in Finland is very old.
We are talking about
two thousand million years
is the age of what we
have below our feet here.
And in that way, it's really stable
and it represents the most
ancient parts of this Earth.
High-level waste will be disposed of
with cast-iron copper canisters,
and the canisters are put into the hole
in the deposition tunnels
and then these are
surrounded by bentonite clay.
Clay has a low hydraulic conductivity,
which means that the water
doesn't transport through the clay.
The spent fuel, when it's taken from
the reactors into the disposal,
it's highly radioactive.
But with time, the
radioactivity will decrease.
After 500 years, people can
stand beside the canister
and it's not dangerous.
But there are some other
long-lived radionuclides
which might be harmful
in case they were to
come up to the surface
and into the drinking water,
into the wells or biosphere,
and therefore the geological disposal
will isolate the waste
for 100,000 years.
- This area isn't prone to earthquakes
or other natural disasters.
Geologically, it's about
as peaceful as you can get.
So, the plan is: dig the tunnels
and then, for 100 years,
put the casks of waste in,
and then backfill each tunnel with clay
so they're encased in solid rock.
And once the site is full,
fill in every bit of it,
every last tunnel, and
then leave it forever.
There are multiple levels of containment.
The idea is that even if
one or two of them fail,
everything will still be
safe for 100,000 years,
unless someone digs it up.
When the US government was thinking about
using Yucca Mountain as its storage site,
they commissioned a now-famous report
on how to mark a site like this.
How do you warn people away,
even if our civilization has collapsed,
our language has fallen apart,
and no one knows what radiation is?
There were all sorts of ideas,
from a spike field to 'forbidding blocks'.
But all those would ultimately
be a big sign saying,
"Hey, there's something
interesting under here; dig!"
- The facilities will be
closed in about 100 years,
6,500 tonnes of uranium.
We have not decided what is
the best way to mark that.
- There was one other idea
in that research paper:
Don't mark the site at all.
One the repository is full,
fill it in, seal it shut, and then hide it
so there's nothing
remarkable at the surface.
There are very few reasons
to dig this deep, particularly here.
The odds are slim that
some future archaeologist
would deside to dig 400 metres
down in this remote location.
And if they did, if someone
ignored all the warnings
or arrived after everything
had been eroded away up top,
well, if they did break
through all the containment
in search of treasure,
what they'd get is radiation poisoning
and a particularly unpleasant death.
If the grave-robbers that
dug up Egyptian tombs
had started rapidly and obviously
dying from a real curse,
maybe they would've taken the hint.
Thank you so much to all
the team at Olkiluoto
who showed me and all the camera teams
who are down here today around.
You can find out more about them
in the links in the video description.
All right, thank you. Your turn!
