In the aftermath of hurricanes, earthquakes, tsunamis or even human error, nuclear power plants pose monumental hazards that must be addressed immediately. Radioactive environments may impede this fast action and limited protective gear can limit humans from taking appropriate and safe action. For this reason, Toshiba has developed and is now testing a tetrapod robot capable of withstanding dangerous radiation while delivering valuable information from inside damaged or decommissioned nuclear reactors.
Toshiba, who provided the Fukushima Daiichi nuclear plant with two reactors, is now trying to help clean up the mess that was caused by the tsunami that hit Japan on March 11, 2011. The still-unnamed robot will help by gathering information about part of the plant that has not been examined yet. Other robots, like some caterpillar style bots, have been used in these efforts, but they cannot reach every space of interest. This tetrapod will be deployed and guided by engineers via remote control, to the plants cooling chamber located within the reactor’s container vessel called the suppression chamber. Levels of radiation in this section were measured to be around 360 millisieverts by a Packbot probe. Toshiba says this tetrapod bot could survive radiation levels of 100 millisieverts for a year. In case the high radiation levels interfere with the robots wireless communications, the bot automatically looks for better transmission.
The Toshiba tetrapot will use 4 integrated cameras to gather information about what the chamber actually looks like. One of those cameras will also be used to keep an eye on an onboard vehicle that is deployed by the tetrapod. This flat surveillance bot carries an overhead, fold-out camera and is tethered to the tetrapod with cables managed by pulleys. This little vehicle is deployed using a robotic arm on the tetrapods back and the cable tether can be cut in case it gets stuck.
The current robot weighs 143 pounds and measures 3’4’’ tall. Each of its four legs has 3 joints that simulate a quadruped. Using its highly flexible joints and nub feet, it can climb up stairs and maneuver in challenging, unpredictable terrain. This first version can also carry 44 lbs (20kg) and has an integrated dosimeter to measure radiation levels. Toshiba says that other versions of the robot could be made to carry 176 lbs (80 kg), climb ladders and climb over obstacles 20’’ tall.
This unnamed bot will be deployed in the Fukushima Daiichi plant in Japan after the plant operator, of Tokyo Electric Power Co. (TEPCO), gives the thumbs up. This nuclear plant is expected to be closed for several decades.
Toshiba made no announcement about whether or not the bot will be used in any hands-on or “robotic arm-on” repairs but its information gathered will surely be useful and it probably makes Toshiba feel helpful.
The bot was displayed 2 weeks ago in Japan where it froze on stage and had to be carried off. If it freezes while one of its legs is in the air, it will fall and has no way of getting up. Hopefully it can overcome its stage fright and technical glitches before it is time to do fire waking through the suppression chamber.
Toshiba is not the only one with a robot in the area, take a look at what else has been used after this link.