An underwater robot captured images of lava-like lumps Thursday inside a damaged reactor at Japan's crippled Fukushima nuclear plant, spotting for the first time what is believed to be nuclear fuel that melted six years ago. Locating the fuel in each of the three wrecked reactors is crucial for decommissioning the plant. Plant operator Tokyo Electric Power Co. says the robot found large amounts of lava-like debris, apparently melted fuel that flowed out of the core into the primary containment vessel of the Unit 3 reactor at Fukushima. Experts have said the melted fuel is most likely to have landed inside the pedestal after breaching the core. It's believed to be covered by highly radioactive water as deep as 20 feet, reports the AP.
The robot, about the size of a loaf of bread and co-developed by Toshiba, is equipped with lights, maneuvers with five propellers, and collects data with two cameras and a dosimeter. It's controlled remotely by a group of four operators. In an earlier survey Wednesday, the robot found severe damage in the vessel but no signs of melted fuel. TEPCO rep Takahiro Kimoto says the robot probe in its two missions has captured a great deal of useful information and images showing the damage inside the reactor, which will help experts eventually determine a way to remove the melted fuel, a process expected to begin sometime after the 2020 Tokyo Olympics. "It's a big step forward," he says. (Read more Fukushima Dai-ichi stories.)