【摘 要】
：
By the Fukushima-Daiichi accident, radio-Cs was released to the environments.Some parts are deposited on concrete.In order to decontaminate, the nature of radio-Cs contamination should be clarified.Co
【机 构】
：
Center for Material Cycles and Waste Management Research,National Institute for Environmental Studie
【出 处】
：
The 14th International Congress on the Chemistry of Cement (
论文部分内容阅读
By the Fukushima-Daiichi accident, radio-Cs was released to the environments.Some parts are deposited on concrete.In order to decontaminate, the nature of radio-Cs contamination should be clarified.Concrete samples were collected from contaminated field.The absolute amount of radio-Cs is extremely small and there is no efficient way to evaluate the distribution excepting radiation measurement.By using beta-ray radiograph,distribution images of radio-Cs with the spatial resolution of 0.1 mm were obtained.There is a logarithmic relationship between the air dose and the penetration depth and the contaminated depth is estimated to be limited in a few mm even in highly contaminated area such as 30 μSv/hr.The radio-Cs is insoluble in concrete.Therefore, it is possible to apply water jet abration for decontamination of contaminated concrete.However,when concrete is immersed into Cs-137 radio isotope solution, Cs-137 penetrated in cm order.The reason of this significant difference between field and laboratory is discussed from the view point of clay adsorption,carbonation, and alkali leaching.Each factor has some effects but the detailed mechanism of radio-Cs penetration in field concrete is still unclear.
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