A structure built to contain hundreds of tonnes of radioactive material from the 1986 Chernobyl nuclear disaster has been unveiled by Ukraine’s president Volodymyr Zelenskiy. The metal shelter for the power plant’s molten reactor number four cost €1.5bn (£1.35bn) to build, with the total figure for the project put at €2.2bn (£1.98bn). The work, which will seal off the reactor’s core containing 200 tonnes of radioactive material, took nine years to complete. At 257 metres long and weighing more than 40,000 tonnes, the shelter has been described as the largest moveable land-based structure ever built. It was designed to prevent further crumbling of the reactor, after a section of the machine hall collapsed in 2012. Some 45 countries contributed to the cost of the project, as well as the European Union and money from the European Bank for Reconstruction and Development. Ukraine itself paid €100m (£90m). Deputy project manager Victor Zalizetskyi, who has been part of the clean-up effort since 1987, said he was “filled with pride” he was able to work on a project “that has such a big importance for all humankind.” However, last week Mr Zalizetskyi said he was worried the war-ravaged nation may struggle to cover the maintenance costs of the new enclosure, warning that work such as dismantling unstable sections of the plant still needs to be completed. He said: “It looks like Ukraine will be left alone to deal with this structure. “The work is not done yet, and we need to think about how to finance this project in the future.” He also said Ukraine is set to widen access to the area to scientists and tourists, saying: “Chernobyl is a unique place on the planet where nature is reviving after a major technological catastrophe.” Chernobyl was back in the global spotlight after a Sky and HBO drama aired earlier this year, showing viewers what life was like in the days, weeks, months and years following the unprecedented disaster. Reactor four at the Chernobyl Power Plant in Pripyat, Soviet Ukraine, exploded and burned on 26 April 1986. The official number of dead stands at 31. The World Health Organisation estimates 9,000 people will die as a result of the explosion at the power plant.