Nuclear waste reprocessing operations produce both high level and medium level activity liquid wastes (HLW/MLW). The major nuclides in these radioactive wastes are those with long half-lives, mainly beta/gamma emitters or alpha emitters such as transuranium elements.
This is why great efforts have been devoted throughout the world to propose harmless storage of these wastes. It seems that MLWs are treated by evaporation in order to concentrate their radioactivity into the smallest possible volume. However this treatment leads to large volumes of concentrates composed of active and inactive salts(NaNO3 y HNO3).
The field of metallacarboranes and their derivatives have become of increasing interest with regard to their solubility, isolation, separation and characterization of organic bases, radiometal carriers, electron acceptor molecules, among other areas. One of these organometallic complexes, [3,3′-Co(1,2-C2B9H11)2]–, has attracted the most attention because of its robustness, its stability in the presence of strong acid (HNO3), at relatively high temperatures and under a very high radiation.
This stability allows it to be considered for nuclear waste remediation. The hydrophobic nature of [3,3′-Co(1,2-C2B9H11)2]– allows extraction of cesium and strontium ions from an aqueous phase to an organic phase, leaving other alkaline and higher-valent metals behind. The ions 137Cs and 90Sr are used for thermoelectric generators and sterilization of medical equipment, among other areas, making the possibility of recycling them very attractive.
In our group new cobaltacarboranes such as these indicated in the figure have been reported to be good for partitioning. The capacity of these compounds have been studied in extraction and membranes.
“Selective separation of M+, M2+ and M3+ radionuclides, namely of Cs, Sr and actinides from nuclear waste by means of chelating hydrophobic cluster anions, focused on the practical decontamination of “MAYAK” (Chelyabinsk-65) area” (PL972004). INCO-COPERNICUS. (E.U.)
“New trends in the separation of 137Cs, 90Sr and Transplutonides from high-level radioactive wastes by means of borane and heteroborane anions”
(Cooperation in Science and Technology with Central and Eastern European Countries)( ERB-3510 PL 92-7779). (CIPA-CT93-0133).
“Nuevas tendencias en la separación de Cs-137, Sr-90 y transplutónidos de desechos radiactivos de alto nivel por medio de aniones de borano y heteroborano”. C.I.C.Y.T.(MAT94-1414-CE).
“Synthesis of Cobaltabis(dicarbollyl) Complexes Incorporating Exocluster SR Substituents and the Improved Synthesis of [3,3′-Co(1-R-2-R’-1,2-C2B9H9)2]– Derivatives”, Inorganic Chemistry, 1997, 36, 2482. C. Viñas, J. Pedrajas, J. Bertrán, F. Teixidor, R. Kivekäs, R. Sillanpää.
“Cobaltabis(dicarbollide) derivatives as extractants for Europium from Nuclear Wastes”, Chemical Communications 1998, 191. C. Viñas, S. Gomez, J. Bertran, F. Teixidor, J. F. Dozol, H. Roquette.
“New Polyether substituted Metallacarboranes as Extractants for 137Cs and 90Sr from Nuclear Wastes”, Inorganic Chemistry, 1998, 37, 14, 3640, C. Viñas, S. Gomez, J. Bertran, F. Teixidor, J. F. Dozol, H. Rouquette.
“Aromatic substituted Metallacarboranes as Extractants for 137Cs and 90Sr from Nuclear Wastes”, Journal of the Chemical Society, Dalton Transations, 1998, 17, 2849. C. Viñas, J. Bertran, S. Gomez, F. Teixidor, R. Sillanpää, R. Kivekäs, J. F. Dozol, H. Rouquette.
“C-substituted bis(dicarbollide) metal compounds as sensors and extractants of radionuclides from nuclear wastes”, Journal of Organometallic Chemistry, 1999, 581, 188, C. Viñas, S. Gomez, J. Bertran, F. Teixidor, J. Barron, R. Kivekäs, R. Sillanpäá, J. F. Dozol, H. Rouquette, Especial Issue con el tema: “Boron Chemistry at the Millenium”.
“New trends in the separation of 137Cs, 90Sr and transplutonium elements from radioactive HLW by borane and heteroborane anions”, ISBN 92-828-3359-3, Luxembourg: Office for Official “Publications of the European Communities, 1998, F. Teixidor, B. Casensky, J. F. Dozol, S. Hermánek, H. Mongeot, J. Rais, “Boron Chemistry at the Millenium” (ISBN 0-444-72006-5), Edited by Professor R. Bruce King.
Other applications of Organoboron Chemistry: “C-substituted bis(dicarbollide) metal compounds as sensors and extractants of radionuclides from nuclear wastes”, C. Viñas, S. Gomez, J. Bertran, F. Teixidor, J. Barron, R. Kivekäs, R. Sillanpäá, J. F. Dozol and H. Rouquette. B. Grüner, J. Plešek, J. Báca, I. Císarová, J. F. Dozol, H. Rouquette, C. Vinas, P. Selucký, J. Rais in New J. Chem., 2002, 26, 1519-1527;
 F. Teixidor, J. Pedrajas, I. Rojo, C. Viñas, R. Kivekäs, R. Sillanpää, I. Sivaev, V. Bregadze, S. Sjöberg in Organometallics, 2003, 22(17), 3414 – 3423.