Every day, engineers around the world are making better, faster, more agile robots. But, this next generation of robot will be doing far more than just amusing crowds. Robots may soon play a critical role in inspecting and cleaning the sites of nuclear disasters. Japan has had a national program in place since 1980 to develop robotics for nuclear power plants, but, since the 2011 Fukushima Daiichi plant disaster, the need for robotic intervention has become clear.
According to Science: "Once it was clear that more capable machines were needed, TEPCO and the government contacted roboticists at Chiba Institute of Technology and Tohoku University. They hastily modified Quince, a survey droid on caterpillar treads that climbs stairs and debris, by equipping it with two cameras, a dosimeter, and a power and communications cable that stretched hundreds of meters. Quince explored the upper floors of the Unit 2 reactor building. More sophisticated versions, dubbed Rosemary and Sakura, were also sent into the reactor buildings. Sakura acts as a communications relay, and Rosemary is equipped with a U.K.-developed system that combines radiation meters, a fisheye camera, and a laser rangefinder to produce 3D radiation maps.
By now, nearly a dozen robots have been developed to get closer looks at the heart of the plant. Some float or swim through pools that have formed in the building’s bowels because of the constant need to inject water to cool the damaged cores. Two snakelike robots crawled through a pipe leading into the 48-meter-tall primary containment vessel in the Unit 1 reactor to ascertain the state of melted fuel masses. Although one got stuck, the machines returned valuable video and dose information, according to TEPCO. In the dark and vaporous interior, the robots measured radiation in one area as high as 25 sieverts per hour—enough to kill a person in minutes.
Makers are now developing robots that can tackle specific decommissioning chores. For example, Toshiba has developed machines that decontaminate surfaces with blasts of dry ice, inspect vent pipes for leaks, and cut and remove debris covering fuel rod assemblies in the Unit 3 building, which was damaged by a hydrogen explosion. Honda developed a robot based on Asimo’s joint-stabilization technology that can extend 7 meters vertically to inspect upper nooks. “Every robot needed differs according to its purpose and the damage,” says Tomohisa Ito, a spokesperson for the International Research Institute for Nuclear Decommissioning in Tokyo, a consortium of nuclear plant companies that aims to develop new technologies for cleaning up the Fukushima plant."
