Six years after the Fukushima Daiichi meltdowns, there’s still a lot of cleanup to be done. Tokyo Electric Power Company (TEPCO) deployed an underwater robot to assess damage inside the Unit 3 reactor in Japan last week, and the robot obtained images of debris that might be melted nuclear fuel. In some areas, the debris was around three feet thick.
The robot captured eerie footage of the damaged reactor at Fukushima, spotting what could be melted fuel. It found what the Associated Press described as solidified lava-like lumps and rocks inside the pedestal that rests beneath the core in the Primary Containment Vessel. In some places the fuel was mixed with broken reactor pieces, hinting at a difficult cleanup to come. The multiple-day exploration started last Wednesday and finished over the weekend.
TEPCO spokesperson Takahiro Kimoto told the Associated Press they now have to analyze the debris seen in the robot-captured images before they can figure out how to remove it.
According to The Guardian, the reactor can’t be decommissioned until all the nuclear fuel has been found and removed – a process that could still span decades. It hasn’t been easy to search for melted fuel at Fukushima due to high radiation levels and damage.
TEPCO said the expedition would help them gain a clearer picture of conditions at the damaged reactors that will aid them in cleanup efforts. The International Research Institute for Nuclear Decommissioning developed the robot, which was inserted into the Primary Containment Vessel through what TEPCO described as a pipe designed to guard against radioactive gas escaping. Thrusters on the robot enabled it to move around through the cooling water that’s accumulated inside the structure since 2011. The robot also had front and rear cameras.