Chernobyl's new shell

A new protective shell is under construction in order to secure Chernobyl’s nuclear reactor. The facility was damaged in a 1986 explosion - the ensuing meltdown was responsible for one of the worst environmental catastrophes of the 20th Century. The scale of the new construction is comparable with that of a sports arena, and involves leading specialists from around the world.

The technical challenges of constructing the new shell are massive. The casing is comprised of an inner and an outer sheath, and the entire structure rests on rail tracks. In autumn 2015, the two protective shells will be joined together and pushed into position over the old sarcophagus. The new, arc-shaped protective shell will be 108 meters (about 350 feet) high.

Under the new protective shell, brackets are installed upon which a crane will later be mounted, allowing the old sarcophagus to be deconstructed via remote control. Nuclear fuel leftovers and highly radioactive ruins will also be removed in this way.

The lining, made from high-grade steel, should hold for 100 years. To prevent problems with corrosion, humidity of the air between the two protective shells must remain at less than 40 percent. The air will be pressurized so that no radioactive dust can escape.

The enormous old ventilation shaft pictured above, now in ruin, became the symbol of the reactor catastrophe. It will be dismantled this year so that the protective shell can be built. A new ventilation shaft stands already finished alongside the old one.

About 2,000 people are involved in the construction process. The specialists and laborers come from dozens of countries. As a result, many different languages can be heard at the construction site.

Experts from the Netherlands work in a nondescript caravan on the building site. They have the duty which carries the most responsibility – they are assembling the arch for the protective shell. As radiation levels increase with height, they are raising the arch step by step as it is built.

The German company Kalzip has been delivering the components for the high-grade steel jacket. The international manufacturer of metal cladding systems has experience with large projects, including building sports stadiums. The Chernobyl project is a big challenge for the engineers from Koblenz in western Germany.

Because of the danger of radiation near the ruined reactor block, the only work allowed to be carried out there is installation. Concrete production, for example, takes place in a specially built site situated outside of the highly radioactive area.

All workers must undergo radiation testing when they leave the construction zone. The maximum allowable dose for people who work in the most contaminated zone near the old sarcophagus is 100 microsieverts per day, or 14,000 per year. In comparison, the maximum allowed exposure for people near atomic power plants is 40 microsieverts per year.