Study of Cesium Adsorption on Marine Clay and Its Application as Sealing Layer
| Autor: | An Hu, 胡安 |
|---|---|
| Rok vydání: | 2018 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 106 Great East Japan Earthquake on March 11th, 2011 stroke Fukushima No.1 Nuclear Power Plant and generated a huge amount of wastes contained radioactive cesium. Since the amount of radioactive waste is too large and the radioactivity is dangerous, offshore disposal facility is a good choice for Japan Government and many points should be satisfied for it. The purpose of this study is to find out the proper material for the 4.0-meter sealing layer of offshore disposal facilities. Contaminant transportation in porous material can be described by advection-diffusion equation. To find the parameters in equation (hydraulic conductivity, diffusion coefficient and retardation factor), Matsushima Bay Clay mixed with bentonite and zeolite is tested by consolidation-permeability test. The cesium concentration of leachate from consolidation-permeability test was measured by atomic absorption spectrophotometer. In this way, the part of breakthrough curve of Matsushima Bay Clay mixture can be measured. Use curve fitting method to find out the parameters in advection-diffusion equation and make prediction of 4.0-meter sealing layer. Test result shows that bentonite makes cesium adsorption ability worse while zeolite make it better. Thickness increasing makes adsorbed cesium amount per sample mass slightly lower. By doing parameter study of advection-diffusion equation, the length of laboratory test in the future can be shorten by using simulation. In the offshore disposal facility design, sealing layer is 4.0-meter-thick and water head difference is 2.0 meter. Simulation shows that even the thickness of sealing layer decrease to 1.0-meter, sealing layer made by marine clay can still make the leakage time of radioactive cesium leachate far longer and cesium concentration quite lower than standard established by Japan Ministry of Environment, which means this design is feasible and very safe. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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