The steel forms of the Cascade Wall were preassembled into massive sections designed to be held in position by the cranes until buried in concrete. The work took weeks. Holes and voids in the walls of Unit Four meant thousands of cubic meters of liquid concrete poured uselessly into the ruins, filling the basement, corridors, and stairwells, until the gaps could be plugged. When the mortar set, radio-controlled explosive bolts released the crane cables, and lifting the next section could begin. But when the corner section of the Cascade Wall—a tower rising sixteen stories above the ground, in a seething gamma field—was finally fixed into position, the explosive bolts failed. The Sredmash specialists sought a volunteer from among the partizans, who agreed to be carried up on a separate crane and release the cables by hand. Before he embarked, they issued him three different dosimeters to record his exposure during the mission. It was an hour before he returned to the ground, where he was rewarded with 3,000 rubles, a case of vodka, and immediate demobilization. But he threw the dosimeters away, for fear of what they might tell him.
* * *
While the Sredmash engineers were at work on the Sarcophagus, a scientific task force from the Kurchatov Institute began trying to unravel the mystery of what had happened to the 180 tonnes of nuclear fuel they believed still lay somewhere within its rising walls. At first, the scientists had believed that most of the uranium had been blown out of the reactor vessel by the explosion and must be scattered inside what remained of the machine hall. But radiation detectors lowered into the ruins by helicopter revealed no evidence of it there. Academician Legasov now worried that if even a small amount of uranium fuel and graphite moderator remained intact and in the correct configuration within the reactor vault, it could lead to a further criticality: the beginning of a new nuclear chain reaction that no one could control, resulting in the release of further radionuclides into the atmosphere around the plant. His colleague, Velikhov, feared that the Sredmash construction crews, blindly pumping concrete over the scattered clusters of nuclear fuel, might inadvertently be building a colossal atomic time bomb.
Yet all their initial efforts to find the uranium fuel inside the reactor hall itself had failed. The members of the Kurchatov task force measured radiation exposure of thousands of roentgen an hour on all available routes through the debris toward the reactor vessel—from below, above, and both sides; they searched for molten lead and the melted residue of the sand, the boron carbide, or the dolomite thrown from the helicopters. But they found no evidence of any of it, and certainly no sign of the fuel.
Eventually the Kurchatov scientists reached one of the rooms in the basement of the reactor hall, three floors beneath—and far to the east of—the reactor vessel itself. Carrying a device that could measure dose rates up to 3,000 roentgen an hour, the team found relatively tolerable levels of radiation along their route. But then they pushed the sensor of the radiometer upstairs, into the space directly above where they stood. There, in compartment 217/2 on mark +6, it encountered a gamma field so hot that the instrument reached its maximum reading and then—its mechanism overwhelmed—burned out. Whatever lay inside was stupendously radioactive and represented a possible clue to the location of the hundreds of tonnes of lost fuel. Yet anyone entering the blackness of corridor 217/2 to find out what it was risked absorbing a lethal dose of gamma radiation in minutes, or seconds.
* * *
Alexander Borovoi, a heavy-set forty-nine-year-old neutrino physicist who had worked at the Kurchatov Institute for more than twenty years, arrived from Moscow to join the task force in late August. It was warm when he disembarked from the Raketa hydrofoil in Chernobyl, where he was issued a set of khaki overalls and two envelopes containing petal respirators—but no instructions on how to use them. That night, an old colleague from the institute just finishing his own shift stopped by to impart the “commandments” on how to survive in the high-radiation zones of the ruined station, accumulated through months of practical experience. To avoid getting lost, he told Borovoi, never enter any room not illuminated by electric light and always carry both a flashlight and a box of matches in case it failed; he warned him to beware of water falling from above, which could carry heavy contamination into the nose, eyes, or mouth; and, most important of all—the First Commandment—be alert for the smell of ozone. The lecturers back in Moscow might tell you that radiation has no odor or taste, he explained, but they’ve never been to Chernobyl. Intense gamma fields of 100 roentgen an hour and above—on the threshold for inducing acute radiation syndrome—caused such extensive ionization of the air that it left a distinctive aroma, like that after a lightning storm; if you smell ozone, his colleague said, run.
The following morning, under orders from Academician Legasov, Borovoi was sent on his first scouting mission into Unit Four.
* * *
As the Kurchatov task force continued its search for the fuel, and the Sredmash teams toiled to complete the Sarcophagus, the technicians of the Ministry of Energy raced to meet their own deadline: the Politburo had publicly promised that the first two of the three remaining Chernobyl reactors would be restored to life before winter set in. But now that the truth of the design faults in the RBMK had finally begun to emerge, the specialists first had to modify the reactors to make them safe to operate, improving their performance by altering the steam void coefficient and the functioning of the control rods. At the same time, they had to decontaminate the entire station from top to bottom, until the fabric of the building itself no longer endangered the operators who would work inside it. The basement cable tunnels that ran beneath the four reactors, flooded with radioactive water during the accident, were pumped dry and the concrete flooring and fireproof coatings chiseled out, ground away, and replaced. The plant’s walls and floors were scoured with acid, stripped with quick-drying polymer solutions, or covered with thick sheets of plastic. The entire ventilation system was flushed of radioactive dust and hot particles or rebuilt, and every piece of electrical equipment in the giant complex was scrubbed clean with a solution of alcohol and Freon, in a process that began in June and would continue for another three years.
But the most dangerous problem was above their heads. Four months after the explosion, the ziggurat roofs of Unit Three and the platforms of the red-and-white-striped ventilation stack looming over the carcass of Unit Four were still littered with fragments of graphite and reactor components, large and small. Fuel assemblies and ceramic pellets of uranium oxide, control rods, and zirconium channels lay where they had fallen, tangled among hoses abandoned by the firefighters who had died weeks before in Hospital Number Six. In some places, the debris was piled into treacherous mounds: a five-tonne concrete panel from the central hall, tossed into the air by the blast, had come to rest amid slick piles of reactor graphite. In others, where the bitumen had melted during the blaze, pieces of wreckage remained welded to the rooftop. All of it was intensely radioactive and would have to be removed before any operators could safely return to the rooms below to run the reactor and turbines of Unit Three.
The government commission turned once again to NIKIMT, the same Moscow laboratory that had suggested using the beetroot pulp now being sprayed over the zone to combat dust. The scientists responded with another ingenious yet thrifty solution, using rags produced as waste in the textile industry to make large mats, soaked in a cheap water-soluble glue and lowered onto the rooftops, where they stuck to the pieces of wreckage. When the glue dried, these “blotters” could be lifted away, bringing the radioactive debris with them, and then removed to be buried. The scientists’ early tests proved successful: with a single square meter of blotter, they could retrieve two hundred kilos of wreckage from a height of seventy meters. But when they asked for permission to use the giant Demag cranes to carry the blotters up to the roof of Unit Three, the commission refused. The cranes were needed twenty-four hours a day for the construction of the Sarcophagus and could not be spared. The NIKIMT team conducted a second successful experiment, deploying
its invention from helicopters, but was then denied permission to fly—because the rotor downdraft recirculated too much toxic dust.
In the meantime, Ministry of Energy technicians planned to clear the debris using robots: one, specifically designed to handle radioactive material, purchased from West Germany and nicknamed “Joker,” and a pair of remote-controlled vehicles developed for use in the Soviet lunar exploration program, modified with small bulldozer blades. To save time and avoid having to move the wreckage to separate disposal sites, the technicians decided to simply shunt it off the edge of the roof, back into the bowels of Unit Four. But the sensitive electronics of Joker quickly failed in the gamma fields of Area M. And even the machines intended for use on the surface of the moon were no match for the inhospitable new landscape they encountered on the roof of the ruined plant. Their artificial brains scrambled, their wheels stuck in the bitumen, hung up on blocks of masonry or snarled in their own cables, one by one the robots all stuttered to a halt.
* * *
On September 16, General Tarakanov received a coded cipher summoning him to a meeting of the government commission in Chernobyl town. By now, Boris Scherbina—after presenting his report on the causes of the accident to Gorbachev in Moscow—had returned as full-time chairman of the commission. The meeting convened shortly after 4:00 p.m. in Scherbina’s lead-lined office, in the district Party committee building on Lenin Street. The chief of the radiation scouts overseeing the cleanup operation above Unit Three spoke first. Yuri Samoilenko, a thickset Ukrainian with a shaggy mop of dark hair and a brooding gaze, looked haggard. His eyes were dark and pouchy. He chain-smoked constantly.
Using a sketch plan of the rooftops, annotated densely with numbered radiation readings and marked with red flags and stars to indicate the most acute hazards, he explained the situation they faced. All technical and automated means to clear the debris field had failed. Radiation levels were enormous. But the roofs had to be cleared before the Sarcophagus was sealed and the sole repository chosen for the most contaminated pieces of reactor debris was thus closed forever. Every other option had been exhausted. It was time, he said, to send in men to do the job by hand.
There was a heavy silence.
The campaign of the bio-roboty—the bio-robots—had begun.
Tarakanov’s soldiers launched their operation three days later, on the afternoon of September 19. Their preparations were rushed, their equipment improvised. An initial test had been conducted in Area M by an Army Medical Corps radiologist who had stepped out onto the rooftop wearing experimental protective clothing and ten separate dosimeters to monitor his radiation exposure. Sheathed in his hood, lead apron, respirator, and pieces of lead sheet torn from the walls of government offices in Chernobyl, the radiologist sprinted across the roof, glanced around quickly, and then tossed five shovelfuls of graphite over the precipice into the ruin of Unit Four. In one minute and thirteen seconds, he absorbed a dose of 15 rem and won the Order of the Red Star. His outfit had reduced his exposure by slightly more than a third, but the gamma field was so powerful that the lead made little practical difference. To the soldiers who followed him, speed remained the best protection.
To prepare his troops for the battlefield, Tarakanov built a full-scale mockup of the rooftops: a new postapocalyptic training ground, this time drawn from life, modeled on aerial photographs of the plant, and scattered with dummy graphite blocks, fuel assemblies, and pieces of zirconium tubing. He issued them crude and hastily manufactured equipment, including shovels, rakes, and wooden stretchers to carry off large fragments of wreckage. They were told to use long-handled tongs to pick up pieces of nuclear fuel and given sledgehammers to break loose the blocks of debris stuck fast in melted bitumen. Tarakanov gathered the men in the room near the roof and used closed-circuit TV images fed from cameras above to brief them on their tasks. To every new detachment, he gave the same speech: “I’m asking any one of you who doesn’t feel up to it or feels sick to leave the team!” Many were young, and reluctant. But if they didn’t do it, who else would?
Years afterward, the general would insist that no man ever broke ranks.
Out on the roof, the men stumbled and ran, weighed down by their clumsy armor, their lead-lined boots slipping and skidding over the slick graphite rubble. They jogged along ramps and scrambled up ladders and paused to catch their breath in the gamma shadow of the vent stack. They scooped up a few fragments of radioactive waste, picked their way to the edge, and flung it out into the sky above what remained of Reactor Number Four. Each man’s task was timed with a stopwatch to keep his estimated dose under the regulation 25 rem. Three minutes, two minutes, forty seconds—it was over quickly, marked by the wail of an electric siren or the clanging of a bell. They were supposed to go out only once, but some men returned to the rooftops again and again. Their eyes hurt, and their mouths filled with the taste of metal; they couldn’t feel their teeth. In Area M, former combat photographer Igor Kostin was overcome by a mystical sensation, as if exploring another world. The radiation was so intense that afterward it became visible on film, seeping into Kostin’s cameras, rising through the sprockets, leaving ghostly traces at the foot of his pictures, like high-water marks after a flood.
When the men came down, they felt as if their blood had been sucked dry by vampires. They curled up and couldn’t move. Every soldier’s work was recorded in a ledger by specialists from Obninsk, the attrition itemized with a grocer’s precision:
Dudin N. S.—Threw down seven zirconium pipes weighing up to 30 kilos.
Barsov I. M.—Removed two pipes of diameter 80 mm, length 30–40 cm . . . 10 zirconium pipes . . . weighing 25 kilos.
Bychkov V. S.—With a sledgehammer, smashed a block of graphite baked into the bitumen.
Kazmin N. D.—Threw down pieces of graphite, up to 200 kilos.
For twelve days, Tarakanov’s army of bio-robots relayed onto the roofs from eight in the morning until eight at night: 3,828 men in all, each of them eventually given a printed certificate and a small cash bonus, admitted for decontamination, and sent home. On October 1 the general declared the operation complete. At a quarter to five that afternoon, following months of repairs, modification, and safety tests, the reactor of Unit One came back online at last. For the first time in five months, the Chernobyl nuclear power plant was once again generating electricity.
On the roof of Unit Three, Tarakanov and the scientists overseeing the clearance staged a small ceremony to celebrate their success. They watched as a trio of radiation scouts wearing blue sneakers and canvas overalls jogged away across the empty expanse of Area M and climbed the ladder rising up the side of the giant vent stack. When they reached the top, 150 meters above the ground, the men lashed a flag to the guardrail and unfurled it in the breeze. From the open door of a helicopter hovering overhead, Igor Kostin captured the image: the red banner stiffening in the wind, a stirring symbol of man’s triumph over radiation.
Eight days later, Tarakanov was climbing into his car outside the plant when he collapsed. After almost two weeks inside his command post watching his troops’ progress on closed-circuit TV, and in repeated visits to the rooftops, the general himself had collected a dose of 200 rem.
* * *
On September 30, news of the completion of the Cascade Wall of the Sarcophagus was splashed on the front page of Izvestia. By that time, the third shift of Sredmash construction unit 605 had arrived in the zone, a force of eleven thousand men with orders to storm onward and finish the project. The chief engineer of the shift, Lev Bocharov, had worked for the Ministry of Medium Machine Building for almost thirty years. A cheerful fifty-one-year-old who strode across the Special Zone in a padded jacket and a black beret, Bocharov had won three state prizes and begun his career with one of the most monumental projects in Sredmash history: raising Shevchenko, a city of 150,000 people, beside a uranium mine on a remote desert peninsula in Kazakhstan. With a labor force of ten thousand Gulag prisoners who lived and worked behind
barbed wire, Bocharov oversaw the construction of the city’s uranium processing facilities, the world’s first commercial “breeder” reactor, the planet’s largest nuclear-powered desalination plant, and everything necessary to support the men and women who ran them, from cinemas to a toothpaste factory.
Bocharov’s task in Chernobyl was the most demanding yet faced by the Sredmash engineers at the site. It was his responsibility to close the steel coffin around Unit Four—by roofing over the wrecked central hall and completing a thick concrete wall between Units Three and Four. This would isolate the ruined section of the building from the rest of the plant and allow the remaining reactors to resume normal operation. But the project had already fallen behind schedule, and the revised completion dates were as absurd as ever.
By now, Unit Four was no longer a recognizable part of a nuclear power plant, its shattered facade enveloped by sheer walls of burgundy-painted, mortar-streaked steel, approached by a muddy rampart and ministered by insect-like concrete pumps and Demag cranes. Above the central hall and the exposed reactor core, radiation levels remained so high that sending in riveters or welders was impossible. So the steel parts of the Sarcophagus were preassembled into the heaviest sections the cranes could lift and designed to be held in place by gravity alone—a massive steel house of cards. Colossal and ungainly, each piece was given a nickname by the engineers, according to its shape or size: the Cap, the Skirt, the Octopus, the Dog House, the Airplane, the Hockey Sticks, and, finally, the Mammoth, a single beam seventy meters long and weighing almost 180 tonnes, so large it had to be delivered to the site on specially manufactured trailers crawling along at four kilometers per hour.
Midnight in Chernobyl Page 34