The trend to put robots in harm’s way, instead of humans, continues. On April 17th a pair of robots entered two reactor buildings of Japan’s Fukushima Daiichi power plant–the plant most severely damaged by the March 11th earthquake. Their job was to determine whether or not the plant was safe for reentry by human repair crews. The robots confirmed what Japanese officials feared: radiation levels were way too high for humans.

The robots used by the Japanese officials were a pair of 510 PackBots. Built by iRobot, the Bedford, Mass. company that makes the Roomba vacuum cleaner, PackBots are already being used by U.S. forces to carry out dangerous operations in Iraq and Afghanistan. PackBots have helped save soldiers lives by neutralizing roadside bombs, car bombs, and other improvised explosive devices (IEDs); they screen vehicles, buildings and people, and they search through high-risk structures such as buildings and sewers.

Upon request by Japanese officials, iRobot sent over a pair of PackBots to help in the “war zones” of crippled nuclear factories. The company modified its 510 PackBots to better investigate the ruined factories, outfitting it with the company’s full hazmat gear: an array of sensors able to detect air oxygen levels, temperature, gamma radiation, as well as hazardous materials and chemicals. The PackBots’ lightweight frames–between 48 and 60 pounds–allow them to nimbly navigate factory debris. Precise control of the manipulator arms enable controllers to adjust equipment or objects inside the plant. The robots are also fitted with a camera that sees in either visible light or infrared and streams the images through a fiber optic cable to a control team safely located hundreds of feet away. In addition to the radiation readings, the video data will allow repair teams to map out salvage strategies for other, heavy-lifting robots as well as for human crews.

After pushing their way through the outer doors of reactor buildings Unit 1 and Unit 3 the PackBot pair collected and analyzed air samples. The news was not good. Radiation levels were 49 millisieverts per hour in unit 1; in Unit 3 they reached 57 millisieverts per hour. To put that into perspective, workers in the U.S. can legally be exposed to 50 millisieverts per year and radiation sickness occurs at 1,000 millisieverts, according the associated press. Prior to the earthquake the radiation limit for Japanese workers was 125 millisieverts. Japanese authorities doubled the limit after the earthquake to 250 millisieverts per year. But even at the increased limit workers at Fukushima Daiichi would absorb their year’s worth of exposure in just 5 hours. The video below shows some great footage from the PackBots as they maneuver inside one of the debris-strewn reactors

resourse : www.nad-co.com