Novarka late last year awarded the steelwork contract, said to be worth around $60 million, to Italy's Cimolai S.p.A., Pordenone. With its headquarters outside Chernobyl's exclusion zone—some 55 kilometers 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.

To protect construction workers from the reactor building's radiation, which is still intense, the confinement vault will be assembled some 300 meters away. When the foundations are complete, Novarka will backfill the entire 90,000-sq-m erection site with clean fill and a partial cover of concrete slabs to shield ground radiation.

Novarka has devised an arch erection sequence that will minimize the use of labor working at extreme heights. Essentially, the joint venture will assemble the vault in five longitudinal sections joined with hinged connections. Raising the assembly with large tower cranes, the steelwork pre-assemblies will rotate around the hinged joints to form the vault.

Using pre-assembled sections up to 300 tonnes and 25 m tall, Novarka will build the eastern half of the arch, then slide it toward the reactor building. Then, in the erection area, the western half will be assembled and joined to the other half before pushing the whole confinement into place.

When the confinement is fully operational, the unstable parts of the old shelter, which was constructed hurriedly after the disaster, will be among the first tasks for the Ukrainian clean-up crew, 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.”