NASA, Energy help Ukraine avoid nuclear disaster

AND HEATHER HARRELD

The Chornobyl (formerly spelled Chernobyl) nuclear power plant's concrete enclosure, which is the only barrier between Ukrainians and deadly nuclear radiation, is crumbling, and two U.S. federal agencies are involved in a project to build a state-of-the-art information technology system to fix it.

Last Thursday the Energy Department and NASA, along with university and industry scientists, successfully tested, for the first time, the computer system they will use to create a defense against potential nuclear disaster.

The system consists of cameras, sensors and mechanical arms, all mounted on a robot, which officials plan to send into the reactor to take images, samples of the concrete and other readings so scientists can construct a virtual reality model of the site. Called Pioneer, the $2.7 million system would enable a "structural assessment of the state of the sarcophagus" and help the Ukrainian government plan repairs, said Maynard Holliday, project director with Lawrence Livermore National Laboratory.

The reactor at the Chornobyl nuclear power plant exploded 12 years ago, and workers quickly built a concrete sarcophagus to encase the contaminated site, and today, the reactor core is still so contaminated that a person exposed to it would receive a lethal dose of radiation in a few minutes. But the barrier has been steadily crumbling. Rain seeping into the facility is draining radioactive material into local ground water, and if the structure cracks or collapses, it would release poisonous dust.

The Pioneer project stems from a DOE program that funds jobs for scientists who worked on Soviet nuclear weapons during the Cold War. A 1994 grant from this program paid for a prototype robot, but the $300,000 was not enough to deploy it. So last year, as top industrial nations and the Ukrainian government signed off on a $760 million plan to repair the Chornobyl shelter, DOE and NASA agreed to fund Pioneer. NASA is participating because Pioneer will test technology for future space missions.

Pioneer employs a new version of virtual reality mapping software first used last summer during NASA's Mars Pathfinder mission to measure rock composition and other features on the red planet. Using pictures taken with a set of three cameras, scientists will map the inside of the Chornobyl reactor and create a 3-D model.

For example, said Ted Blackman, a research scientist with the Intelligent Mechanisms Group at NASA's Ames Research Center, scientists will be able to measure how much radioactive fluid may have spilled inside the reactor, gauge structural cracks in the shelter and collect data on radiation levels, humidity and other conditions.

Geb Thomas, a University of Iowa professor working on Pioneer, said information about the reactor comes mainly from photographs taken by workers who dash inside for a few seconds. "If someone takes a year's dose [of radiation], they have to move to a completely different environment,'' he said.

The cameras and sensors will be mounted on a robot built by RedZone Robotics Inc., Pittsburgh. The robot is similar to one used to clean up underground nuclear waste storage tanks at DOE's Oak Ridge National Laboratory. This summer, RedZone will integrate this equipment with a set of high-powered Silicon Graphics Inc. computers that will process the data Pioneer collects.

An SGI Octane dual-processor system tethered to the robot will process the constant flow of data being conveyed from the cameras. An SGI Onyx-2 visualization supercomputer will then be used to create interactive simulations of the site so scientists can experiment with such scenarios as what would happen to the shelter if a crack were to grow. SGI donated this equipment, along with two other Octane machines for planning, data sharing and diagnostics.

Pioneer also will employ new software that will display a comprehensive model of the reactor room side-by-side with the live picture generated by the cameras. The software, called Projected Texture, provides a "God's eye'' view of the space where the robot is moving and will help the operator guide the device.

"People view this kind of technology as unrealistic, as a video game you wear on your head,'' said Linda Jacobson, a virtual reality evangelist for SGI, but "it's a mission-critical tool." Pioneer is scheduled to be shipped to Ukraine in the fall.Attempts to reach Ukrainian officials last week were unsuccessful. According to news reports, they are not completely certain they need the system, but Bruce Thompson, vice president of engineering with RedZone, said, "That mentality is starting to change.''