Remediation of Uranium-Contaminated Concrete Using Various Extractants
نویسندگان
چکیده
A great amount of radioactive concrete waste was produced from the decontamination and decommissioning of a research reactor and uranium conversion plant at KAERI. To reduce the volume of concrete waste, a separation technology of porous fine cement paste from the gravel and aggregate in concrete through a thermal and mechanical treatment was developed [1]. However, since some gravel and aggregates still have higher radioactivity than the limited value for self-disposal, they have to be washed by appropriate decontamination reagents. Carbonate, because of its ability to be recycled and its tendency to have great selectivity for uranium, was observed to be an effective way to remove uranium from uranium-contaminated soil [2]. However, the use of carbonate for the decontamination of concrete has been little reported. Strong acids have been used to wash soil contaminated with radioactive nuclides. In this study, carbonate solution, nitric acid and sulfuric acid were used for the extraction of uranium from the concrete contaminated with uranium, and their efficiencies are compared to one another. In addition, the amount of waste sludge produced from the using these extractants was also evaluated.
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