The radiation is so strong that even the most advanced material technologies and robotics are not able to deal with it. Five years after the disaster in Japan caused by a tsunami, the Fukushima Daiichi nuclear power plant is still radioactive. Humans, of course, cannot come anywhere near there, and even the machines are having difficulties to carry out decontamination work. The main problems are the contaminated water buildup in reactors that were affected by the tsunami. The pieces, with some weighing tons, were partially melted when the reactors at Fukushima were broken and even the Tokyo Electronic Power, responsible for the management of the plant, you know exactly where they are located, since they were taken with the force of the waves.
Of the four buildings that made up the unit, only one could be cleaned yet. In the other three, access is difficult even for robots, which need to clean debris, and immersed several times in search of cells. In all attempts made so far, the radiation was so great that made the wires to melt that connect the parts of the machine, making them useless and nothing more than obstacles that make it more difficult to carry out debris.
It is a time consuming and especially costly process. Since the disaster, the estimate is that the Tokyo Electronic Power has already spent millions of dollars building robots and methods to decontaminate Fukushima, often without success. Each robot takes about two years to develop, it must be built specifically for the buildings that will venture from which, to date, none returned.
However, the company is optimistic. In some points of Fukushima, radiation levels are already acceptable to humans and more than eight thousand people work there, either in debris removal, construction of tanks for the transfer of contaminated liquids or dismantling remains of the nuclear plant. But the main effort is to keep the cooled reactors damaged by a steady stream of water, so they do not return to explode.
The more effort now is to prevent this filthy water from leaking into the ocean. According to the company that ran Fukushima, the site work is only 10% complete and the expectation is that everything returns to normal in the next 40 years. This, of course, taking into account the technology to deal with the extreme radiation appear in the near future. Before that, it is only an estimate.