Images captured by an underwater robot on Saturday showed massive deposits believed to be melted nuclear fuel covering the floor of a damaged reactor at Japan's destroyed Fukushima nuclear plant. The robot found large amounts of solidified lava-like rocks and lumps in layers as thick as 1m on the bottom inside a main structure called the pedestal that sits underneath the core inside the primary containment vessel of Fukushima's Unit 3 reactor, said the plant's operator, Tokyo Electric Power Co. On Friday, the robot spotted suspected debris of melted fuel for the first time since the 2011 earthquake and tsunami caused multiple meltdowns and destroyed the plant. The three-day investigation of Unit 3 ended on Saturday. Locating and analysing the fuel debris and damage in each of the plant's three wrecked reactors is crucial for decommissioning the plant. The search for melted fuel in the two other reactors has so far been unsuccessful because of damage and extremely high radiation levels.
An underwater robot captured images of solidified lava-like rocks 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. Plant operator Tokyo Electric Power Co. said the robot found large amounts of lava-like debris apparently containing fuel that had flowed out of the core into the primary containment vessel of the Unit 3 reactor at Fukushima. The plant was destroyed by a massive earthquake and tsunami in March 2011. This image captured by an underwater robot shows lava-like lumps believed to contain melted fuel inside the Unit 3 reactor at Fukushima. Experts believe the fuel melted and much of it fell to the chamber's bottom and is now submerged by radioactive water.
Toshiba unveiled a remote-controlled robot with tongs on Monday that it hopes will be able to probe the inside of one of the three damaged reactors at Japan's tsunami-hit Fukushima nuclear plant and grip chunks of highly radioactive melted fuel. The device is designed to slide down an extendable 11-meter (36-foot) long pipe and touch melted fuel inside the Unit 2 reactor's primary containment vessel. The reactor was built by Toshiba and GE. An earlier probe carrying a camera captured images of pieces of melted fuel in the reactor last year, and robotic probes in the two other reactors have detected traces of damaged fuel, but the exact location, contents and other details remain largely unknown. Toshiba unveiled the device carrying tongs that comes out of a long telescopic pipe for an internal probe in one of three damaged reactor chambers at Japan's tsunami-hit Fukushima nuclear plant - this time to touch chunks of melted fuel Toshiba's energy systems unit said experiments with the new probe planned in February are key to determining the proper equipment and technologies needed to remove the fuel debris, the most challenging part of the decommissioning process expected to take decades.