They’ve Got It Covered: Enormous Arch Moved Into Place Over Damaged Chornobyl Reactor
Thirty years after the world’s worst nuclear disaster, the gargantuan structure built to confine radiation at the Chornobyl Nuclear Power Plant is now in place after inching – literally – into position.
The massive arch was slid into place on Teflon-coated steel rails. The arch, known as the “New Safe Confinement,” was built 180 meters (about 200 yards) west of the damaged power plant, the only way for the construction site to be safe enough from radiation to allow workers to build it. The 36,000- metric ton (40,000 short ton) structure began sliding to the east on Nov. 14, moving 60 centimeters (23.6 inches) at a time to come to rest atop the disaster site two weeks later.
``The arch is absolutely mind-boggling when you see it,’’ said Mac McNeil, Bechtel’s managing director of the shelter implementation plan. ``It completely dominates the landscape and the plant that is there. It’s like looking at a mountain.”
The arch is large enough to cover several Statues of Liberty or St. Paul’s Cathedral.
Moving the largest mobile structure ever built on land is a challenge that stands apart from the feat of designing and building the arch. The system sliding the two “legs” of the arch has to stay perfectly synchronized while the array of angled jacks shoves for a minute, retracts for a minute, then repeats, for days. Amid all this pushing, the two sides of the arch can never slip more than 20 millimeters (0.7 inches) out of alignment, despite the legs being 257 meters apart, wider than the length of two U.S. football fields.
"You can imagine if one side of the arch got too far ahead of the other it would bind up and you might not be able to recover it," McNeil said.
Bechtel, which led a consortium that designed the structure, now provides oversight of engineering and construction work being performed by a joint venture of French contractors Vinci Construction and Bouygues Travaux Publics known as Novarka. The arch is scheduled to be finished in 2017, when the walls enclosing the ends of the arch are sealed in place.
Here is a timelapse video of the arch moving into place: