Correlation between Different Type of Caesium Carrier in The Radiocaesium Interception Potential Measurement for Forest Soils

Abstract

Radiocaesium, especially 137Cs, is one of major heavy fission product radionuclide that has a relatively long half-life and acts as a dangerous persistent pollutant to the environment. It could be dispersed widely through the atmosphere during nuclear weapon test and reactor accident such as Fukushima Dai-Ichi Nuclear Power Plant (FDNPP) disaster in Japan. High retention of radiocaesium in the surface of forest floor surrounding Fukushima area is important issues to measure further potential risk of health and environment contamination. Radiocaesium Interception Potential (RIP) values are related to the sorption capacity of radioactive Cs in clay minerals, and in this study, we investigated the correlation between different type of Cs carrier to the RIP and their adsorption character in soil. The RIP values of all soil sample were varied from 27.27 to 522.66 mmol kg-1. The carrier effect on RIP was conducted using carrier 134Cs, carrier-free that contains 134Cs, 136Cs and 137Cs and 133Cs stable isotopes. Correlation between different type of carrier suggests a relatively lower RIP for stable caesium as a carrier. This phenomena could be caused by competitive adsorption among of caesium ions in the frayed edge sites of soil mineral. Organic carbon content and CEC also contributed to the RIP value. No significant difference found of C/N ratio and CEC values between deciduous and coniferous forest soil as they also have similarity of mineral content in soil.