Study on Decontamination of Radioactive Cesium From Soil by HTS Magnetic Separation System

By the accident of the Fukushima Daiichi Nuclear Plant, radioactive substances have been scattered in the environment. The decontamination of radioactive substances in the soils and the wreckage, and the volume reduction of contaminated waste are urgent issues. In this study, we examined the possibility for the soil decontamination of Cs-137, the main radioactive species with longer half-life, by means of the magnetic separation with a high-temperature superconducting magnet. We investigated the desorption behavior of the nonradioactive cesium from several kinds of clay minerals, and the removal rate by the ferromagnetic adsorbent from the aqueous phase. The results showed the possibility of the removal of cesium from the clay. Based on the results, we proposed a magnetic separation system of radioactive cesium by using high gradient magnetic separation with a superconducting magnet.