2015 年 1 巻 4 号 p. 7-10
The serious nuclear disaster in the Fukushima Daiichi nuclear energy plant of the Tokyo Electricity Power Company was occurred by the tsunami which was caused by the Great East Japan Earthquake on March 11, 2011. The radioactive materials emitted by the disaster were widely diffused in and around Fukushima prefecture including the Pacific Ocean by wind, rain and a flow of river. It can’t be always said that there is no risk of the condensation of radioactive materials in human’s body by ecological chain if fish take in radiation in the ocean contaminated by the radioactive materials. However the effective decontamination methods of the radioactive materials are not developed and the decontamination is less-advanced. The establishment of a new decontamination method is urgent need and indispensable in light of disadvantageous effect on ecological system. Thus, in this study, it is aimed to establish a new decontamination technology of radioactive materials deposited on seabed or lake bed. In particular, the new adsorption material which can adsorb radioactive materials is developed and the new method which can move them from the bottom sediment is proposed. The results obtained from various tests with or without the water circulation and the adsorption material indicate that the water circulation is effective and that the adsorption material has a great deal of potential in the decontamination of radioactive materials. It is expected that the proposed method and the developed adsorption material are efficient to remove radioactive materials from seabed or lake bed when they are expansively applied to the real decontamination.