Rapid and Reliable Elimination System for Radioactive Cesium Using Magnetic Nanocomposites

Abstract

We have devised the rapid elimination system for the contaminated radioactive cesium using magnetic nanocomposites. The Great East Japan Earthquake hit caused a serious meltdown of the overheated fuel rods and the release of radioactive chemicals into the environment. Until now, fuel rods have been cooled using seawater to control its temperature, therefore huge amount of waste water containing high concentrations of radioactive cesium have been continuously generated. On the other hand, radioactive cesium is easily condensed in the fly ash originating from incineration of garbage. The garbage incineration plant is overflowing with the fly ash which cannot be discarded (when the radioactivity of fly ash exceeds 8000 Bq/kg, we cannot discard it as a usual manner). Prussian blue is known as an effective eliminator of radioacitive cesium from seawater and fly ash slurry, however complete and rapid collection of Prussian blue dispersed in water is very difficult. Recently, we have developed a novel form of magnetically guidable Prussian blue coated magnetic nanocomposite clusters via the application of nanotechnology for drug delivery system. Using this type of nanocomposites under magnetic field, we have confirmed that 99.9% and over 80% of cesium were rapidly removed from seawater and fly ash, respectively.