Novarka late last year awarded the steelwork contract, said to be worth around $60 million (€40M), to Italy’s Cimolai S.p.A., Pordenone. With its headquarters outside Chernobyl’s exclusion zone, some 55-km away at Slavutich, Novarka is jointly owned by Paris-based contractors Vinci S.A. and Bouygues S.A. Novarka won its turnkey contract in September 2007.

Novarka has devised an arch erection sequence that will minimize the use of labour and working at height. Essentially, it will assemble the vault in five longitudinal sections joined with hinged connections. As it raises the assembly with large tower cranes, the steelwork.

Pre-assemblies will rotate around the hinged joints to form the vault

Using preassembled sections up to 300 tonnes and 25-m tall, Novarka will first build the eastern half of the arch and slide it towards the reactor building. It will then assemble the other half in the erection area and slide the previously complete section back to joint it before pushing the whole confinement into place.

When the confinement is fully operational, dismantling unstable parts of the old shelter put up hurriedly after the disaster will be among the first tasks for the Ukrainian clean-up programme, says Novak. After that, he adds, “studies suggest that further waste management operations should be deferred for 30 to 40 years to gain some benefits from the (radioactive) decay process.”