A swimming robot showed just how bad the damage at Japan’s Fukushima nuclear plant is. The robot dubbed “the Little Sunfish” went inside the factory and captured images of the containment vessel in the Unit 3 reactor, which was swept away by the massive earthquake and tsunami in March 2011.
No signs of melted nuclear fuel yet
Toshiba Corp., the company which has been given the responsibility of cleaning the plant, has co-developed the swimming robot with the International Research Institute for nuclear decommissioning. The robot is on a mission to locate the fuel that melted and seeped from the core, falling to the bottom of the primary containment chamber where it was surrounded by highly radioactive water as deep as 6 meters, notes the Review Journal.
The little Sunfish is a small robot which propels around the area and captures data using two cameras and a dosimeter. Further, the robot is controlled by a group of four operators from a remote distance. The robot, which is about the size of a loaf of bread, is connected to data cables all the time. Further, the observations made by the robot are sent back to the team via the data cable.
On Wednesday, plant operator Tokyo Electric Power Co. (TEPCO) spokesman Takahiro Kimoto stated that they had received the first pictures of the underwater damage from the swimming robot, but there is no sign of the melted nuclear fuel that researchers are looking for.
In a late night news conference, Kimoto said, “The damage to the structures was caused by the melted fuel or its heat.”
Inside the plant, the robot was placed near the structure known as the pedestal, from where it went further in search of more information and the possibility of stumbling upon the melted fuel.
Third attempt using the swimming robot
The Tohoku earthquake and tsunami in 2011, which killed more than 18,000 people, also damaged the power plant in Fukushima, making it the largest nuclear accident since Chernobyl. There have been a couple of attempts to explore the first and the second reactor, but the robots could not pass through. They either got stuck or swallowed by the excessive radiation still present inside the plant. However, the Little Sunfish gave a glimpse of the badly damaged number 3 reactor.
Meanwhile, the budget allocated to the exploration and clean-up process more than doubled to a whopping $188 billion last year, but the agenda is still running behind schedule. TEPCO has also not been able to decide on what to do with the 777,000 tons of water contaminated with tritium when it was used to cool down the plant’s cores.
Earlier, TEPCO Chairman Takashi Kawamura stated that there is only one solution left, which calls for dumping the water tanks into the Pacific Ocean. According to the officials, tritium is not harmful in small doses, but local activists and fisherman said that this will a create another negative impression about the country’s environmental commitments, which are already not in a good place as it deals with the horrible nuclear disaster.