Robots sent to clean up Fukushima after nuclear disaster, have died from radiation
It appears that not even robots can survive a nuclear disaster. Five years ago, a magnitude 9.0 earthquake triggered a massive tsunami that hit the northeastern coast of Japan. It obliterated several prefectures, killing nearly 19,000 people and damaging four reactors at the Fukushima Daiichi nuclear power plant.
Following the 2011 disaster, five robots that were sent to Japan’s Fukushima Daiichi nuclear power plant have “died” due to the effects of leaked radiation.
There is still a massive amount of radiation at the Fukushima plant and removing the melted fuel rods, the source of the problem, is proving an incredibly difficult and dangerous challenge.
Tokyo Electric Power Co (Tepco), owner of the power plant, had sent in numerous bots inside the power plant, including bots that were able to swim underwater. The robots were sent to locate some of the harder-to-reach rods. But as soon as the robots got close, the radiation destroyed their wiring.
It is unclear whether a more resistive technology can be developed. Further, the last robot to make use of muon rays (an X-ray-like tech) only returned “grainy” images before it was lost to the effects of radiation.
The untimely death of these bots leaves Tepco in a state of perplexity, as it struggles to deal with the disaster and the radiation leaking into the water.
According to ScienceAlert, the Tepco has dealt with only 10 percent of the mess created by the tsunami and subsequent meltdown.
Justin McCurry of the Guardian reports, “Of greatest concern, though, is reactor 1, where the fuel may have burned through the pressure vessel, fallen to the bottom of the containment vessel and into the concrete pedestal below – perhaps even outside it – according to a report by the International Research Institute for Nuclear Decommissioning. Reactors 2 and 3 are thought to have suffered partial meltdowns.”
The site manager, Akira Ono, said he is “deeply worried” that radioactive water, used to cool down the reactors and then stored in tanks, will leak into the sea again.
However, the good news is that the robots, built by Toshiba, were able to remove 1,535 spent fuel-rod assemblies from the reactor 4 building before they went kaput, but the radiation levels were lower there, making it easy to perform the job. But Reactor 3 has been a different story. The radiation levels are much higher and the sensitive electronics and wires inside the robots couldn’t handle it.
Unfortunately, a new robot cannot be sent inside to complete the job. Naohiro Masuda, head of decommissioning at Tepco, told Reuters that each robot was custom-built for each building and it took two years to get each one built and ready for action. There appear to be no understudies waiting in the wings. And in fact, a robot capable of withstanding the high levels of radiation environment doesn’t exist.
Tepco thinks a serious effort towards cleanup can begin in 2021 and it is currently estimated that it could take up to 40 years to decommission the plant.