Russian scientists from the Frumkin Institute of Physical Chemistry and Electrochemistry of the Cola Bay Research Center of the Russian Academy of Sciences, Moscow State University, Peoples’ Friendship University of Russia and Mendeleev Russian University of Chemical Technology developed a technology for effective extraction from water solutions of technetium, a radioactive element contained in the waste of nuclear power plants (NPP). It is an important step in enhancing safety and security while disposing of the NPP nuclear waste.
The researchers synthesized new chemical compounds based on crown ethers – ring-like molecules capable of selectively uptaking the metal ions. When a technetium ion gets into the center of such a ring, it is reliably held by the oxygen atoms directed inwards like a kind of ‘teeth.’ The size of these molecular rings proved optimal to uptake the technetium, while the strength of bonding with the crown ethers is higher than with the molecules of water, which makes it possible to hold the metal inside.
To enhance the effectiveness of extraction scientists added an organic solvent – chloroform – to the solution. As a result, technetium was 30 times more actively converted into an organic phase, from where it is much simpler to extract. The researchers are hopeful that the technology they had developed will be adopted and will simplify and expedite the purification of radioactive waste from technetium.
The problem of radioactive waste remains one of the most important ones since these contain long-lived isotopes which pose a serious threat to the environment. Traditional methods, such as burial in the deep geological layers, require a lot of resources and do not give a full guarantee against possible leaks. In this connection new scientific research results open a perspective of reducing the risks for the nature and mankind.
