The simulation of reactive radionuclides transport through concrete barrier
| Autor: | Lin, Wen Sheng, 林文勝 |
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| Rok vydání: | 1995 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 83 The EQ3NR geochemical equlibrium model and HYDROGEOCHEM geochemical transport model are used to simulate the radionuclides transport through concrete barrier made from four brand cements, "TAIWAN ", "ASIA", "CHIA SHIN", "UNIVERSAL". reaction is incorporated into the geochemical transport model to account the variation of concentraion due to nuclides decay on the simulating domain and boundary. After validating the models, four nuclides, Co-60 Sr-90 Cs-137 I-129, are selected for modeling release from the waste canister. Three transport schemes included diffusion under a constant concrete porosity, advection and diffusion/dispersion under a constant concrete porosity, advection and diffusion/dispersion under a changable concrete porosity are investigated. An one-dimensional reactive radionuclides transport for aqueous complextion, oxidation/reduction, dissolution/precip concerntration are similar for four brand concrete barriers, (2) only Co(OH)2(s) precipitated at the interface of the waste canister and the bottom of concrete, (3) the maximum concentration of Co-60, Sr-90, Cs-137 appear on 50, 100, 100 years respectivel simulated time increases at the bottom concrete and backfill clay interface. (4) the nuclides concerntration are similar for both types and transport schemes, (5) the nuclides concerntration of type transport schemes are one order of magnitude greater than type and transport schemes at the bottom concrete and backfill clay interface. It suggests that adsorption/desorption reactions should be included in the reactive radionuclide transport model in the future study. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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