“The Novarka company resumed work on the assembly of steel structures and panels in the open-access zone on February 20,” the press service said.

Novarka is building a giant, arch-shaped structure out of steel, 190 meters (623 feet) wide and 200 meters (656 feet) long, to cover the crumbling concrete dome that was built following the explosion. The steel casing project is estimated at $1.4 billion and is expected to be completed in 2015.

Wall panels and parts of the roof caved in on February 12 in the turbine hall at the plant's Reactor Number Four, the site of the world's worst nuclear disaster in 1986. The damaged area covered about 600 square meters (6,456 square feet).

No one was hurt in the incident and the radiation level in the so-called exclusion zone around the plant has not changed, the power station's management said at the time.

The evacuation was carried out as a precautionary measure, Novarka said earlier.