STUDY ON EXTRACTION AND ADSORPTION OF CESIUM FROM VERMICULITE MIXTURE SAND

Abstract

A large amount of radioactive materials were diffused by the accident at Fukushima Daiichi
nuclear power station of Tokyo electric power company, and decontamination has been continued for about
six years in Fukushima. The contaminated soil that is stripped on the ground and is collected should be reduced
in volume at an intermediate storage facility. However, it takes a long time to operate the facility. The ministry
of the environment shows the guidelines that it is possible to dispose the radioactive waste below 8000Bq/kg
of radiation dose in an ordinary process. Therefore, it is more desirable that the radiation dose should be reduced
below 800Bq/kg in flexible containers filled with contaminated soil than the reduction of radiation dose in the
intermediate storage facility. Thus, in this study, the method in which only radioactive materials are collected
from the contaminated soil in the flexible containers is proposed. The extraction of radioactive cesium from
the soil is investigated so as to check the performance and availability of the proposed method. As a result, it
is confirmed that is possible to collect a certain amount of cesium from the cohesive soil like vermiculite in
which cesium is strongly fixed.