QUANTITATIVE EVALUATION ON CONCENTRATION DISTRIBUTIONS IN THE DEPTH DIRECTION OF RADIOACTIVE CESIUM ACCUMULATED AT A LANDFILL DISPOSAL SITE IN FUKUSHIMA PRIFECTURE

Abstract

Waste such as grass and trees with radioactive cesium that was scattered widely due to the accident at Fukushima Daiichi nuclear power plant was buried in a landfill disposal site after intermediate treatment. Therefore, in order to clarify the current status of the radioactive cesium accumulated in the landfill disposal site, the radioactive cesium concentration in the depth direction was investigated. A hole with a diameter of 10 cm and a depth of up to 100 cm was dug in the landfill disposal site, and a small amount of waste was collected from the hole and the radioactive cesium concentration was measured with a germanium semiconductor detector. From the present study, the tendency of the distribution of radioactive cesium concentration in the depth direction was quantitatively clarified. In addition, it was found that since the distribution of the radioactive cesium concentration in the depth direction from the landfill surface was complicated, the tendency of that cannot be predicted using the conventional exponential function model used for general soil.