A shape-changing robot designed to inspect the inside of the containment vessels of the crippled Fukushima Daiichi nuclear power plant in Japan stalled and was abandoned as it made its first inspection of the plant's Unit 1 reactor on Friday.
The robot, which was developed by Hitachi-GE Nuclear Energy and the International Research Institute for Nuclear Decommissioning, had inspected 14 locations out of 18 on its list, when it stopped moving, the Tokyo Electric Power Company said.
Unit 1 is one of three reactors that suffered from meltdowns after the back up cooling system at the plant failed in March 2011, the results of a 9.0-magnitude earthquake event that triggered a tsunami that breached the plant's perimeter.
The robot, which weighs about 16 pounds, has adjustable crawlers that enable it to reshape itself. This includes shortening or lengthening from about 10 inches to slightly over two feet. Its width can adjust from two and a half inches to 10 and a half inches. It can also change from a straight alignment to a U-shape.
TEPCO tested the robot for several weeks, then sent it through a 10cm (about 4 inch) pipe on Friday for the first robotic look inside the pressurized containment vessel.
After snaking through the pipe, the robot was lowered by cable to a grating on the first floor of the vessel.
The robot was outfitted to measure temperature, radiation levels and to send back photographic images. The mission on Friday was considered a partial success, in that the robot inspected 14 different sites before failing. But the plan called for a further exploration of the inside of the PCV this week. Instead, after failing to revive it after it stalled, TEPCO workers were instructed to cut the cable to the robot.
Why the robot failed was not reported, but this robot was not waterproof and the bottom of the containment vessel is filled with water. A waterproof version of a shape-changing robot is in development and is expected to be ready in March 2016.