Swimming and wriggling robots unveiled for Fukushima clean-up
Image credit: Jiji press
University and industry scientists have demonstrated new robots specialised for moving through and searching scenes of destruction that are impossible or dangerous for humans to enter.
Hardy, agile, remote-controlled robots will be vital for the decommissioning of power plants, particularly in the case of the Fukushima Daiichi Nuclear Power Plant, which suffered a meltdown in 2011 following a devastating tsunami and earthquake.
Robots can spend hours or days in environments so highly radioactive that a human worker would be killed in seconds.
The Japanese government hopes to start the challenging task of removing hundreds of tonnes of melted fuel after the Tokyo 2020 Olympics, potentially beginning work in 2021. For this to be possible, engineers need to know the exact location of the fuel, and understand the extent of the structural damage to the reactors.
Among other efforts, a snake-like robot was used in 2011 to explore the reactors, but was trapped repeatedly by obstacles and its camera was blocked. A “scorpion” inspired crawling robot also failed to navigate the site and was abandoned inside.
Years later, a new version of the snake-like robot has been revealed by Japanese scientists, including a team from Tohoku University in Sendai: a region severely affected by the tsunami and earthquake.
The robot stretches to eight metres in length, has a camera attached to the front and can move at speeds of up to 10cm per second.
It wriggles in a serpentine motion, propelled by the vibrations of the brush-like hairs that cover its body. Unlike any other robot, it can also “rear” its tip like the head of a snake, shooting a small jet of air to lift it. This allows it to climb over obstacles – such as debris in a disaster zone – up to 20cm in height.
According to Professor Satoshi Tadokoro of Tohoku University, the robot could search for people trapped in collapsed homes following earthquakes, and test the structural safety of damaged buildings. The researchers hope to have it ready to assist in search and rescue operations and other tasks within three years of durability testing.
Meanwhile, an alternative disaster relief robot has been unveiled by Toshiba and the public International Research Institute for Nuclear Decommissioning. This swimming robot is the size of a loaf of bread is and fitted with lights, camera and tail propellers.
It is designed specifically to inspect meltdown damage at the Fukushima nuclear plant, and will enter the primary containment vessel of Fukushima’s Unit 3 this summer to locate melted fuel in radioactive water.