Researchers in Europe have built the world's largest land-based moving structure to cover the nuclear fallout from Chernobyl, the power plant that suffered a catastrophic meltdown in 1986.
The mega structure was unveiled at the site in Ukraine this week and is designed to prevent further deadly radiation spewing from Chernobyl for at least the next century.
The massive arched dome is dubbed The New Safe Containment and cost 1.5 billion euros to build.
It has now been moved on top of the concrete that was hastily poured over the failed nuclear reactor in the wake of the meltdown. Now the dome is in place, work can begin on dismantling the so-called sarcophagus surrounding the reactor, built to contain the fallout from the explosion 30 years ago.
The Chernobyl disaster in the then Soviet Ukraine was the worst civil nuclear accident in history. Thousands of people were exposed, with radiation spreading through Europe.
The gargantuan structure weighs in at around 36,000 tonnes, is 108 metres high and 162 metres long.
"The New Safe Confinement is an unprecedented engineering success. It is an extremely complex structure build in a contaminated area," said Vince Novak, the nuclear safety director from the European Bank for Reconstruction and Development.
"It's one of the most important projects ever done. People in Ukraine and not only Ukraine - across Europe and large parts of the world - still remember the 1986 accident," Mr Novak told Reuters.
The hi-tech covering of the disaster zone has been "eagerly awaited" and is "huge news and not only for people of Ukraine, for people of Europe, people of the world. It's a huge technological achievement."
To minimise risk to those involved the structure was mostly built away from the site and slid onto the area this week.
Even with the concrete sarcophagus that has encased the failed reactor, there was still the chance radiation could leak out or the concrete building would collapse.
"Now with the New Safe Confinement even if this happens, nothing will leak out in the environment. Yes, it will create a mess within the New Safe Confinement, nobody wants this to happen. And this is why part of the strategy is this early deconstruction of the most unstable part," Mr Novak said.
THE LEGACY OF CHERNOBYL
Reactor Number 4 of the Chernobyl nuclear power plant exploded during an experimental safety check in the middle of the night on April 26, 1986. It spewed radioactive contents up to one kilometre into the sky, some falling as debris in the area while the rest was blown by the wind as far as western Europe.
Thirty rescue workers and plant staff, receiving abnormally high doses of radiation, were killed at the site either immediately or in the coming weeks.
The noxious plumes drifted to the northwest, polluting the Soviet republics of Ukraine, Belarus and Russia. The harmful clouds then reached Scandinavian countries before swinging southward and westwards, dropping contaminated rain on central Europe and the Balkans, Italy, France, Britain and Ireland.
Soviet authorities remained silent on the disaster for three days without informing people in nearby villages about the need to evacuate. The official news agency TASS only reported on the accident on April 28 after the Forsmark nuclear plant in Sweden detected unusually high radiation in the environment.
One hundred thousand people were eventually evacuated from an area within 30 kilometres of the plant only weeks later.
In November 1986 a 50-metre-high concrete shelter, dubbed a sarcophagus, was completed to prevent further leakage of radiation from tonnes of highly radioactive magma and allow the other three reactors at Chernobyl to continue producing power for Ukraine.
The concrete sarcophagus was only meant to be temporary and expected to last a couple of decades. But in 1993 its lifespan was estimated at only seven years.
In December 2000 after years of international pressure, the Ukraine government finally agreed to switch off the last reactor at the site and close down the Chernobyl facility.