DIFFUSION OF Cs-137 AND Sr-90 IN SOILS
A simple procedure for measuring diffusion of Cs-137 or Sr-90 in soils was used by depositing a very thin film of high specific activity tracer on the surface of samples. Soil moisture contents were maintained at controlled conditions by the use of a pressure plate extractor. Thin sections of sample were cut off and radioactivity measurements were made on the surface of the portion remaining after each cutting. The experimental method applied was tested to fulfill the boundary conditions of the law for instantaneous sources. Based on the exponential absorption law and through mathematical manipulations, the diffusion coefficients of Cs-137 and Sr-90 in soils were evaluated by a graphical method from the solution of the boundary conditions. Diffusion of Sr-90 in various kinds of soil in Taiwan was observed. However, movement of Cs-137 in some soils was too slow to determine its diffusion coefficients. Soil clays, bentonite, illite, and kaolinite were also used as diffusion media for these two radioactive ions, for the purpose of studies on the comparison between clay fractions and clay minerals as diffusion of tracer concerned. Diffusion of these two bracers in electrodialyzed sodium-, potassium-, and calcium-ion-saturated samples were also studied. From the experimental results, structure of clay minerals, clay contents, species of exchangeable cations, and moisture contents were concluded to be the factors affecting the diffusion of Cs-137 and Sr-90 in soils. (JAIF)
- Research Organization:
- Taiwan Sugar Experiment Station, China
- NSA Number:
- NSA-17-030034
- OSTI ID:
- 4683178
- Journal Information:
- Proc. Japan Conf. Radioisotopes, Journal Name: Proc. Japan Conf. Radioisotopes Vol. Vol: 4th
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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