At 5:30 pm on Sunday 27 November 2016, the installation of the new sarcophagus to protect what remains of the Chernobyl nuclear power plant was completed. An immense 36,000-tonne covering has been lowered over the site that in 1986 was the scene of one of the most serious accidents in the history of nuclear energy: the structure should hold for at least a century and make it possible to contain the radioactive dust, preventing it from dispersing into the atmosphere.

The new sarcophagus, 30 years after the Chernobyl disaster

Seen from a distance, the sarcophagus resembles an enormous arch, 109 metres tall and 162 metres long. Earthquake-resistant, it is capable of withstanding a force-3 tornado. The manoeuvres to install it had begun on 14 November, using around 200 hydraulic jacks, under the guidance of the Novarka consortium, controlled by French companies Bouygues and Vinci. The total cost came to 2.1 billion dollars, financed by the European Bank for Reconstruction and Development.

"With the installation of the sarcophagus, the first step is complete. We now have a year to install the waterproof membranes and carry out tests such as ventilation and fire safety checks," Nicolas Caille, director of Novarka, explained to the French daily Les Echos. The final chapter on the consequences of the Chernobyl accident (at least as far as securing the site is concerned) could therefore arrive by 30 November 2017, when the contract signed by the consortium and the Ukrainian authorities expires. More than 30 years after the reactor explosion and in the face of incalculable human and economic costs.

Inside, 80% is now highly radioactive magma

Inside the new structure, work will then need to proceed to dismantle the first sarcophagus that was built in the aftermath of the disaster. The steel beams will have to be sawn through and access gained to the interior in order to retrieve the materials. Which by now, for at least 80 per cent, consist of highly radioactive magma.

It will therefore be necessary to conceive, fund, build and deploy a team of robots capable of carrying out the clean-up task, given that a human presence would be far too dangerous. "This second phase of works therefore looks set to be particularly lengthy," the French newspaper notes, "and it is not known when it will begin. The risk is that, given the lifespan of the new sarcophagus, a great deal of time may pass before a decision is made to intervene."