Research

Separation of valuable or harmful chemical trace components (radionuclides, metals, metalloids) from solution is difficult because they often exist in the presence of overwhelming majority of other, mainly harmless chemical species of much higher concentrations. We have successfully developed highly selective inorganic ion exchange materials that are of have been used in more than 60 industrial applications worldwide in the nuclear industry and produced scientific knowledge understanding on the origin of selectivity to tailor new materials for the nuclear field. Research for applications and knowledge is also underway for the separation of natural radionuclides, in hydrometallurgy and for metal recycling.

A suite of commercial inorganic ion exchange materials was developed together with Fortum in the 1990s (then Imatran Voima Oy) comprised CsTreat®, SrTreat® and CoTreat®. The first industrial application was that of CsTreat® at Loviisa nuclear power plant (NPP) in 1991 continuing still today after 31 years of highly efficient operation. Early industrial application sites in 1990s included Olkiluoto NPP (TVO, Finland), Callaway NPP (Union Electric, USA), Paldiski naval base (Estonia), Murmansk naval base (Russia) and Tokaimura (JAERI, Japan). In the 2000s the new major industrial application was at Savannah River R-105 Reactor (USDOE), Sellafield Nuclear Reprocessing Plant (BNFL, UK), Dounreay Prototype and Demonstration Fast Reactors (NDA, UK).

The major operations at Bradwell Magnox NPP (ElectricSolutions) at Fukushima NPP accident site started in 2012-2013 are still underway. At Fukushima, more than 700 000 m3 heavily contaminated highly radioactive waste water has been purified of Cs-137 and Sr-90 below detectable level which indicates a purification factor in the order of 107.
While having the advantage of high selectivity compared to organic ion exchange resins, the diffusion of ions in the crystalline inorganic materials is often low which means that the volumetric operating capacities are low. To overcome this limitation research is underway to develop inorganic ion exchange materials in nanofiber formats. Here, Na-titanates and other materials with high kinetic performance have been prepared.