Radiation Shielding Properties and Freeze-Thaw Durability of High-Density Concrete for Storage of Radioactive Contaminated Soil in Fukushima

Abstract

In this research work, high-density concrete (μ = 4.71 g/cm³) using steel balls as aggregates and a normal concrete using recycled aggregates from the debris of the demolished concrete buildings of the earthquake-affected region have been evaluated for the radiation-shielding property for the radioactive contaminated soil in Fukushima. Two cylindrical model containers for storage of radioactive contaminated soil samples have been made using these two types of concretes. From the results of the experiments, it was demonstrated that the high-density cylindrical concrete container with a concrete-shield thickness of 100 mm can reduce radiation-dose equivalents emitted from radioactive cesium in contaminated soil by up to 90%. Good agreement was observed between the experimental and calculated-dose rate using Monte Carlo simulation (MCNP4C2 code) for two types of concrete for various shield thicknesses and measurement distances. Also, the freezing and thawing durability of high-density concrete was found to be superior to normal concrete using recycled aggregates.