CHERNOBYL With clockwork cadence, a 27-ton hydraulic hammer suspended from a huge crane pounds rhythmically on a large pillar, pushing it 24 m deep into the earth. Right next to it stands Chernobyl's infamous reactor No. 4, which is draped in a shapeless steel sarcophagus. The protective cover is more for show than anything else, considering the isotopes that keep leaking out of it.
A quarter-century after the nuclear disaster April 26, 1986, this obsessive drilling sound punctuates the building site of a huge state-of-the-art radioactive shield. More than a shield really, the $2 billion Novarka project, as it is known, is a coffin. Its aim is to lock up the radioactive monster once and for all, and put an end to this disastrous legacy of the Soviet Union in about four years.
The Novarka project is a joint venture involving French companies Bouygues and Vinci, which are currently working on the structure's foundation. Philippe Regnault is the head of the project's civil-engineering department. One of his favorite pastimes is to draw red crosses on a map to indicate where supporting pillars have already been driven into the earth. "In December, I'll be done with my pillars," he says.
This is not Regnault's first overseas assignment. Before arriving in Ukraine, he helped build a launchpad for the European spaceport in French Guiana, a thermoelectric power station in Pakistan and a gas tank in Egypt. In Ukraine, he doesn't have to deal with the jungle or Asian monsoons. But he does face an insidious, invisible enemy whose presence can only be detected through the high-pitched vibration of the Geiger counter. "That's why this building site looks like absolutely none other," Regnault says.
That's also why the Novarka project's 600 workers must deal with a long list of very particular workplace constraints. To reach the building site from Kiev, Ukraine's capital, visitors have to cross two checkpoints located on the edge of the contaminated zone. Once they are on the site, they have to undress, leave their clothes in a locker, walk in their underwear through a series of changing rooms, put on a long-sleeved uniform despite the scorching heat, hang two different Geiger counters around their necks, show their passports to two zealous Ukrainian militiamen and climb onto a roof along a 50-cm-wide decontaminated strip. Only then can they can look down at the building site, which stretches over 8 hectares.
The 300 "worker ants" dressed in white overalls who bustle about 30 m below are already part of another world: the world of the atom, where the workers can stay no more than five hours a day for one month before leaving the premises for 15 days of rest.
Experts in radiology determined the location of the site based on radioactivity measurements taken all around Chernobyl. They even took readings high up in the air, thanks to a pilot balloon.
To limit the volume of radiation, the shield which is supported by a 23,000-ton metal framework will be assembled exactly 300 m west of the damaged reactor. Another 100 m further to the west, radiation levels will be lower still, but the building site will bump into the limit of the safety zone, which is protected by two rows of barbed wire and watched by the Ukrainian secret service. To the east they face other constraints: the whole area is occupied by reactor No. 3, which Ukrainian authorities still hope to make work again.
The two parts of the shield will be assembled on rails, which the crew with the help of powerful hydraulic jacks will later use to move the structure toward and finally over the reactor to isolate it. The delicate task of moving the shield 300 m is expected to take four days. Once in place, the shield will be monitored from afar to avoid any human activity close to it. It will be equipped with a ventilation system and sensors to evaluate corrosion levels.