Watch: Fukushima Robot Finds Chunks Of Nuclear Fuel Debris Underwater

An underwater robot deployed into one of Fukushima's defunct nuclear reactors discovered what appeared to be hunks of melted fuel debris. Video recorded by the robot showed "lava-like" lumps inside the submerged No. 3 reactor. The robot was sent into the reactor through a pipe meant to prevent the escape of radioactive gas, Reuters reported Thursday. Operators aimed for the machine to locate radioactive melted fuel rods in order to remove them and continue decommissioning the plant. Discovering the melted fuel would mark a major accomplishment for plant's cleanup process.