It's called "nuclear lava." Fortunately, the hellish stuff exists in only one place: Chernobyl. After the No.4 nuclear reactor blew its top on Apr. 26, 1986, tons of scorching nuke fuel oozed from room to room, consuming cement, melting steel pipes, and contaminating everything in its path. With time, the mess cooled and congealed. Today, a floor of rock-hard, radioactive lava marks history's worst nuclear accident.
In places, the lava wells up eerily from the floor. One such "stalagmite" looks like an elephant's foot. Curiosity is dangerous, though. Every second you linger, you're getting zapped by radiation. Even quick visits in protective suits can mean soaking up 30 rads (a unit of radiation exposure). That's about 100 times the dose most people get in a year from X-ray exams and sunlight. But Chernobyl workers regularly brave the danger to monitor conditions inside.
Despite their daring, the workers haven't been able to keep up with the deterioration of the concrete-and-steel sarcophagus that was hastily thrown over the reactor 12 years ago. It is now sinking into the wreckage. The vault is cracking and rain seeps in, creating radioactive ponds that threaten the water table. And when the wind picks up, workers have to spray chemicals on the debris inside to keep radioactive dust from being blown into the atmosphere. Left untended, the structure could collapse, unleashing another deadly cloud of radiation over the Ukrainian countryside some 75 miles north of Kiev. So the Group of Seven has pledged $758 million to reinforce the tomb. The job will take years--and would surely claim many lives if done exclusively by humans.
VALIDATION. Instead of sacrificing more lives, robots will handle the repairs. That's turning Chernobyl into a testing ground for new robot technology, because the machines able to withstand its invidious radiation will be top contenders for many future cleanup tasks. Nuclear reactors built in the '70s will begin reaching the end of their design lives in the 2010s and will need to be dismantled. By 2030, some 400 plants will probably be decommissioned. Each could require a small army of robots that spends years on the task--further swelling the reviving market for these steel-collar workers. "Everyone wants a chance to validate their technologies" at Chernobyl, says Maynard A. Holliday, an investigator at the Energy Dept.'s Lawrence Livermore National Laboratory in Livermore, Calif.
That potential demand adds more luster to these mechanical marvels, which have staged a dramatic turnaround. In the 1980s, robot sales headed downward. They bottomed out in 1987 at $299 million. For the next six years, the market bounced around in the $400-million range. Since 1993, though, robots have been coming back. Last year, shipments squeaked past the $1 billion mark for the first time in the U.S. Much of the market is for factory robots. But it includes so-called field robots--such as the one being developed for Chernobyl--designed for all sorts of hazardous tasks, such as repairing offshore oil rigs and inspecting underground storage tanks (table, page 170).
There will also be glamour work for mobile robots in space, which is "hot" because there's no atmosphere to screen radiation from the sun. An early endeavor could be constructing the international space station, once its materials are launched late this year and next. And future NASA missions call for robots to explore other planets, mine asteroids, and maybe build a moon base.
Chernobyl will test the mettle of the toughest machines, though. Intense radiation is lethal for ordinary silicon chips, so the computer brains and sensors commonly found in robots won't do. The first company to get a crack at Chernobyl will be Pittsburgh-based RedZone Robotics Inc., a spin-off from Carnegie Mellon University. RedZone's engineers are putting together Pioneer, a $2.7 million robot funded by NASA and the Energy Dept. that moves on tank tracks and carries various radiation-hardened equipment.
Pioneer should roll into the Chernobyl sarcophagus sometime this summer to map the lava's radioactivity and make stress tests on the shelter. The information will help Chernobyl officials plan the immense job ahead--first, shoring up the vault, and eventually removing the lava.
If Pioneer performs well, it promises to be the basis for a new generation of muscular construction robots to be manufactured in Ukraine. The technology will be given to a Ukrainian startup that can engage local nuclear weapons scientists. They will create newer and better machines--and, it is hoped, resist the temptation to sell their services to aspiring nuclear powers.
TOY STORY. Still, many Ukrainian officials are cool to the U.S. robotics push. In the drab brick buildings around the entombed reactor, Chernobyl's managers complain that Americans, their eyes on missions to distant planets, are foisting unnecessarily complex technology on Ukraine. "For me, the robot is just an expensive toy," grumbles deputy director Valentin Kupny. "I don't need it."
While anxious to protect their children from radioactivity, the Ukrainians have special respect for the workers who regularly dart into the wreckage to snap pictures or measure the accumulating rainwater. Technician Sergei Koshelov ventures in several times a month. "The main thing is, you have to get out fast," he says. Deputy manager Artur Korneev, who decorates his office with photos he took in the reactor's poisonous central hall, doubts Pioneer can improve upon the work already done by humans.
Chernobyl's caretakers also worry about costs. Maintaining the tomb for Reactor No.4 is taxing Ukraine's meager cash resources. The Ukrainians were dismayed late last year when they learned that the cost of Pioneer was to come out of Washington's $78 million contribution to the G-7's rehabilitation plan. The Ukrainians wanted to cancel the robot and restore the $2.7 million. "It was almost a showstopper," admits Timothy Denmeade, RedZone's business development manager. Washington agreed to fund the robot separately.
RedZone's engineers hope the Ukrainians will learn to love Pioneer once they see it in action. Unlike a human rushing about with a camera, the 1,000-pound robot, designed to withstand a staggering 1 million rads, can explore all 2,500 square meters of Chernobyl. Dragging a 100-meter power and remote-control line, it will push its way through the rubble behind a small bulldozer blade, clearing paths that will also help people dash in and out faster.
The robot will send back streams of information, including visual images. The Livermore team that devised the vision system for the Pathfinder robot, which gave humans new visions of Mars, is creating a "rad-hard" version for Pioneer. And researchers at the University of Iowa's Ames Research Center are preparing a "smart" coring arm that will extract samples of the concrete structure. As this tool bores into a surface, it measures the force required and analyzes the material's chemical composition. Later, NASA may use the coring arm to drill into a comet.
The Chernobyl data will be compiled in a 3-D map. With mouse clicks, engineers will be able to read chemical composition, temperature, radiation levels, and structural strength at almost any particular spot--an invaluable aid for planning the massive shelter repair work ahead.
For RedZone, the project is a long-delayed homecoming of sorts. The company was created following the 1986 Chernobyl disaster, when a group of Soviets flew to Pittsburgh and asked William L. "Red" Whittaker for robots like the ones that Carnegie Mellon built for the Three Mile Island cleanup. Whittaker founded RedZone to provide the technology--but ran afoul of U.S. government controls on high-tech exports to the Soviet Union.
So RedZone turned to building robots for the nuclear industry. It has been a small but steady business. But once RedZone's technology braves the killer rads of Chernobyl, it could be in hot demand for hazardous chores.