The bell rang, and the soldier ran. He wore a lead apron hammered together that morning in a workshop, lead sheets in his boots and a strip of lead under his cap, and his job for the next ninety seconds was to shovel as much graphite as he could off a rooftop, hurling load after load over the edge into the smoking ruin below. Then the bell rang again and he ran back, his war over — regulations forbade a second trip. The graphite had been inside Chernobyl's reactor No. 4 until the night it exploded; the rooftop belonged to the neighbouring reactor No. 3. The Soviet Union had tried machines first, but the ferocious radiation fields scrambled the electronics of robots borrowed from the lunar programme and bought from West Germany. So it sent men instead, under a nickname of grim precision: bio-robots.
The catastrophe began at 1:23 a.m. on 26 April 1986, when a botched turbine safety test sent reactor No. 4's power surging out of control. Two explosions hurled the reactor's enormous lid aside, tore the building open and set the graphite core burning in the open air, lofting radioactive dust over Ukraine, Belarus and Russia and, in the days that followed, much of Europe. Moscow said nothing until workers at a Swedish nuclear plant more than 1,000 km away triggered their own contamination alarms two days later. Pripyat, the model atomic town of nearly 50,000 people three kilometres from the plant, was evacuated only after 36 hours, its residents told to pack for three days. None of them ever moved back.
What followed was the largest clean-up operation in history. Roughly 600,000 people from across the Soviet Union — soldiers, miners, drivers, engineers — were eventually registered as liquidators. Helicopter pilots flew through the plume again and again to drop some 5,000 tonnes of sand, clay, lead and boron onto the burning core. Coal miners from the Donbas tunnelled beneath the reactor by hand, in ferocious heat, to make room for a cooling system that in the end was never switched on. And three plant workers — Alexei Ananenko, Valeri Bezpalov and Boris Baranov — opened valves in the flooded basement to drain water that, had molten fuel reached it, might have caused a second, far larger steam explosion. Legend insists these 'Chernobyl divers' died horribly within weeks; the record shows all three survived the mission, and in 2018 Ukraine formally decorated them for it.
The rooftops of Unit 3 were the worst assignment of all, strewn with reactor graphite emitting doses that made even minutes dangerous. Under Major General Nikolai Tarakanov, roughly 3,500 men cleared them in timed sorties of between 40 seconds and a few minutes each — one man, shovelling load after load to the edge, before the bell called him off the roof for good. Many later said the arithmetic was the point: each man was allowed to spend a single, carefully rationed share of his life up there, and no more.
The Elephant's Foot
That December, investigators exploring beneath the wreck found what the core had become. Molten fuel had mixed with sand, steel and concrete into a substance called corium, oozed through pipes and corridors, and set into a wrinkled black mass that someone christened the Elephant's Foot. Early estimates made it one of the most radioactive objects ever measured: lingering beside it for a few minutes in those first months would have been a death sentence. The best-known photographs, taken years later by the inspector Artur Korneyev, are blurred and grainy partly because radiation fogged the film. The Foot is still there, hardening and slowly crumbling — the lava of a volcano that human beings built themselves.
An arch to outlast a century
The first attempt to entomb the reactor, the steel-and-concrete Sarcophagus, was thrown up in just 206 days by crews who often could not stay in position long enough to tighten a bolt; it was heroic, leaky, and given a design life of only a few decades. Its successor was conceived on a different scale entirely. The New Safe Confinement, financed by an international fund backed by more than 40 governments at a cost of roughly €1.5 billion, is an arch 108 metres high with a span of 257 metres — roomy enough to cover St Paul's Cathedral. Because welding directly above the reactor was impossible, engineers assembled it 300 metres away and then, over about two weeks in November 2016, slid all 36,000 tonnes of it into place along Teflon-coated skids. It is the largest movable land-based structure ever built, sealed against the weather and fitted with robotic cranes to dismantle the ruin beneath, and it is designed to last 100 years.
Outside the plant stands a monument to the liquidators, dedicated to those who saved the world. Behind it on the skyline rises the second, vaster monument, the silver arch — a century of borrowed time, purchased ninety seconds at a time.
Quiz nuggets
- Reactor No. 4 at Chernobyl exploded at 1:23 a.m. on 26 April 1986, during a botched turbine safety test.
- Soldiers who shovelled graphite from the roof of Unit 3 in sorties as short as 40 seconds were nicknamed bio-robots; roughly 3,500 served there.
- The Elephant's Foot is a solidified mass of corium — melted fuel, sand, steel and concrete — found beneath the reactor in December 1986.
- Contrary to legend, all three 'Chernobyl divers' who drained the basement water survived; Ukraine decorated them in 2018.
- The New Safe Confinement, a 36,000-tonne arch with a 257-metre span, was slid into place in November 2016 — the largest movable land-based structure ever built.