Toshiba Corp and General Electric have unveiled the robot that will again try to achieve what no robot has been able to accomplish before it; locating and removing the spent, melted nuclear fuel of the Fukushima Daiichi nuclear reactor number three.
The cleanup and decommissioning of the three nuclear reactors that fell victim to meltdowns after a powerful earthquake and subsequent tsunami in 2011 is ongoing. The cleanup will cost the equivalent of USD$190 billion.
The path to decommissioning began with locating the spent, melted nuclear fuel inside the reactors. No human can withstand the radiation levels present in the reactors. Consequently, radiation-resistant robots have been sent down to attempt to locate the fuel. But, all the robots that were entrusted to finish the job have all stopped short due to the large radioactivity present in the reactors.
Caption: A remote-controlled melted fuel probe device is unveiled by Toshiba Corp. at its facility in Yokohama, near Tokyo, Monday, Jan. 28, 2019. 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. (AP Photo/Mari Yamaguchi). Read more at: https://phys.org/news/2019-01-toshiba-unveils-robot-probe-fukushima.html#jCp
However, a probe with a camera attached to it successfully managed to get images of the melted fuel in Unit 2’s reactor last year. The other two reactors’ melted fuel is still unseen, but engineers are confident they have detected it and can find it easily.
Back in 2017, the cleanup crew sent a Toshiba robot named the Scorpion Robot down to the No. 2 Reactor. The radioactivity caused the robot to stop midway and disabled one of the wheels. There is still no indication of where the spent fuel exactly is.
Engineers have tried four-legged robots, stair-climbing robots, robots with wheels, robots that could swim through water, and more. They all seemed to be unable to complete the mission.
In with the new
The new robot by Toshiba Energy Systems & Solutions Corp and GE is a device engineered to traverse into the hard to reach places in the nuclear reactors. The robot will go down an 11-meter long pipe and will be in reach of the melted nuclear fuel in Unit 2.
The robots are fitted with tongs that will attempt to grip the melted fuel and extract it. It also has lights and electronic measurement equipment at the tip of the pipe that will do the relevant tests the engineers need to determine if the extraction is done safely and efficiently.
Toshiba Corp.'s energy systems unit group manager, Jun Suzuki, shows a remote-controlled melted fuel probe device at its facility in Yokohama Monday,. 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. | AP
Jun Suzuki, a Toshiba ESS group manager for the project said:
"Until now we have only seen those deposits, and we need to know whether they will break off and can be picked up and taken out. Touching the deposits is important so we can make plans to sample the deposits, which is a next key step."
The issue is that there might not be anything of value to pick up with the robot’s tongs when the robot goes down into the reactor in February of this year. However, the engineers at Toshiba say if the robot is unable to lift anything out of the reactor, that will also be a key finding. The Fukushima Meltdown aftermath is an engineering conundrum of epic proportions, and it's not over yet. Perhaps the engineers may have just figured out how to get closer to ending it with their novel tong-robot. Even if it's by taking baby steps.
Works Cited
“Toshiba Unveils Robot to Probe Melted Fukushima Nuclear Fuel.” Phys.org - News and Articles on Science and Technology, Phys.org, phys.org/news/2019-01-toshiba-unveils-robot-probe-fukushima.html#jCp.
“Toshiba Unveils Robot with Tongs to Probe Melted Fukushima Nuclear Fuel.” The Japan Times, www.japantimes.co.jp/news/2019/01/29/national/science-health/toshiba-unveils-robot-tongs-probe-melted-fukushima-nuclear-fuel/#.XFCmWVwzZPY.
