SUBJECT: This is the largest movable structure ever built.
It's taller than the Statue of Liberty,
longer than two jumbo jets, and nearly three times the weight
of the Eiffel Tower.
This mega structure is the engineering feat
of an architect's dreams.
And beneath it is a radioactive nightmare.
In 1986, a surge of power destroyed one of the reactors
at Chernobyl nuclear power plant,
leaving behind a toxic disaster.
An extreme amount of radiation was
leaking into the environment, and by extreme amount,
I mean like 400 times more than the radioactive fallout
that followed the atomic blast in Hiroshima, Japan.
About 200 people were hospitalized immediately.
More than two dozen of them died.
And at least 150,000 nearby residents
were forced to leave their homes.
At the time, the long-term effects of the radiation
exposure were still unknown.
To make matters worse, because of weather patterns,
radiation from the Chernobyl disaster
spread across the region and far into Western Europe.
And what remained at the Chernobyl plant
was close to 200 tons of nuclear fuel and radioactive elements
emitting lethal amounts of radiation.
So engineers had to act fast to keep
more radiation from spreading.
In an effort to contain the power plant,
an army of workers known, as the liquidators,
started constructing a tomb.
The liquidators worked day and night
to contain the worst of the radiation inside the reactor.
And then they built a concrete steel sarcophagus
around the whole building.
It took 206 days, and more than half a million liquidators, who
wore little to no protection.
The structure was only meant to last 20 to 30 years.
And the tomb was never successfully sealed,
so there was no way to protect it
from the corrosion and environmental damage that
happens with anything that's outside.
If the structure were to collapse,
it's believed that a radioactive dust cloud would
be ejected into the atmosphere.
And that sort of fallout would be devastating
not only for Ukraine and the surrounding countries,
but potentially for the entire planet.
To really understand how devastating it could be,
we need to dive into some nuclear physics.
Spent or used nuclear fuel, like the kind inside the Chernobyl
plant, consists primarily of uranium, plutonium,
fission products, and minor transuranic elements.
Some of the most significant fission products or radioactive
isotopes released during the Chernobyl disaster
were Iodine-131, Cesium-137, Strontium-90,
and Plutonium-241.
These isotopes can take lifetimes to decay
and then be considered harmless.
The rate at which they decay is measured
by their half-life, which is the time it
takes for a radioactive substance
to lose half its radioactivity.
Now Iodine-131 decays in a matter of days.
And Cesium-137 and Strontium-90 have half lives about 30 years.
The real problem child is Plutonium-241.
While this isotope has a half-life of only 14 years,
the isotopes that are formed during its decay
are terrifying.
It decays into Americium-241, which has
a half-life of about 432 years.
And then Americium-241 breaks down
into Neptunium-237, an incredibly stable isotope,
which sounds good, but it's bad.
It has a staggering half-life of 2.14 million years.
Essentially, this means that if the old structure covering
Chernobyl were to collapse, our planet would probably never
recover from the fallout.
Since this would be an international disaster,
it needed an international solution.
So more than 40 different countries,
along with engineers, architects, and financiers,
stepped in and contributed to Plan B, B as in big,
really, really big.
The New Safe Confinement, or NSC, as it's called,
is large enough to entomb the old Chernobyl sarcophagus.
The massive arch is made of multiple layers
of rustproof stainless steel, and it's
designed to withstand extreme temperatures and even
natural disasters.
The space between the inner and outer cladding
is incredibly important.
It holds a complex ventilation system
which regulates humidity, temperature, and pressure.
And that will prevent corrosion and keep radioactive dust
from escaping the structure.
One of the greatest challenges was deciding
where to build this giant tomb.
Because of the radiation leaking from the damaged plant,
the structure couldn't be constructed directly over it.
So to keep workers safe, they built the NSC in two halves
300 meters away from the power plant.
And this is where the major engineering feat comes in,
because the arch needed to be moved over the reactor.
And moving a 35,000-ton structure has never been done
before.
Each of the halves were lifted at separate times
and moved onto specialized rails.
Once they were connected, the arch
then inched its way very carefully
over the existing sarcophagus.
Now the challenge is to seal this giant tomb, which
is expected to be completed by late 2017.
And then remotely operated cranes inside the arch
will begin dismantling the unstable old sarcophagus.
The New Safe Confinement is expected
to last at least the next 100 years,
but damage from the Chernobyl disaster is irreversible.
Today we're starting to understand
the human cost of nuclear fallout,
as cancer rates and other health impairments
rise among people exposed to Chernobyl's radiation.
While this feat of engineering showed
what could be accomplished when faced with one of the worst
disasters in human history, capping
a radioactive catastrophe is not a permanent solution.
Let's not forget those radioactive isotopes will still
be decaying for millions of years to come.
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Once the original Chernobyl sarcophagus is dismantled,
the radioactive waste will be removed from the site.
To find out where radioactive waste is stored,
check out this video.
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