Success in Developing Innovative Process for Removing and Recovering Radioactive Cesium from Incinerated Ash

August 27, 2012

 JNC Corporation (head office: Chiyoda-ku, Tokyo, President: Michio Morita) has succeeded in developing the technology for removing and recovering radioactive cesium on a laboratory scale, targeting contaminated water from washing incinerated ash, to allow short-time and low-cost treatment.


 Radioactive cesium is currently detected, even in trace amounts, from incinerated ash of decontaminated waste, and also vegetation, general waste or the like at incineration plants in various places in East Japan, and development is required for the technology of efficiently removing and recovering radioactive cesium.

 Our Company has so far established the technology for removing and recovering cesium (stable isotope), aiming at application to treatment of radioactive cesium-contaminated water including seawater (the simplified schematic process is shown below). However, radioactive cesium is hardly contained in water around the living areas at present, and most of it are diffused, adsorbed in soil and vegetables and recycled in various places in East Japan. On the other hand, radioactive cesium is confirmed to be contained in incinerated ash of general waste, sewerage sludge, or the like.

 The present technology is applied to removing and recovering radioactive cesium from contaminated water from washing incinerated ash. As compared with the case of using solid adsorbents such as zeolite, this technology allows radioactive cesium to be decreased to an undetectable level within a very short treating time (several minutes) only by a single operation, and also allows a significant reduction in waste volume.

 Moreover, the material to be used is industrially easily available and there is no need for exchange of filters and adsorbents. Therefore, operation cost is decreased which contributes to a significant reduction of treatment expenses. Furthermore, the technology applies a magnetic separation method. Therefore, an operation with low exposure, in a closed environment or by remote control, can be realized.

 Our Company currently aims at establishing a process for industrially removing cesium for the purpose of treating large volumes of water from washing incinerated ash. Our Company further intends to complete the technical development on a bench scale within this year as a goal under collaboration with Ichihara City, Chiba Prefecture.