| Radioactive waste disposal, which is related to the land and the environment security, is the key link in the development of nuclear industry. In recent years, the nuclear waste management in china is in the process of improving the level of technology and the key period for the construction of the disposal facilities. The curing process of nuclear waste has been widely concerned in the most important part of the multi-barrier system. Currently, though the ceramic curing technology are not mature enough, it is widely studied as a new type method of curing the high level radioactive waste attributed to its good thermal stability and chemical stability and good mechanical properties.The stable mineral systems of glass ceramics and artificial rock ceramics are successfully prepared and its properties were characterized by feldspar mineral systems in this research. As one of the main components of basalt which is suitable for disposal of the radioactive waste in china, the mineral of albite can effectively cure the radionuclides with strong adsorption capacity and the formation of mineral phase is conducive to block the migration of radionuclides, and thus ensuring the safety and reliability of the solidified body. This paper made the first attempt on the study of the ceramic solidification with albite mineral system.Glass ceramics and artificial rock ceramic containing multivalent elements are designed and synthesized and characterized successfully in the first place. The results show that the leaching rate of glass ceramic solidified body is varied from 10-6 to 10-5 and decreased with the extension of soaking time. The main phases of the artificial rock is the sodium feldspar which have excellent performance on the condition of the sintering temperature is at 1300 oC for 2h. Despite of lacking quantitative analysis, the intensity of the diffraction peak of the spectrum is close to 90%. The magnitude of leaching rate of element contained in artificial rock solidified body is lower 1~2 than that of the glass ceramics, which indicates artificial rock solidified body are well in performance of anti-leaching.In addition, the effect of heat treatment temperature and reaction rate on the sintering of glass ceramics was studied and the leaching mechanism of the artificial rock was discussed on the basis of the previous experimental study. The results show that the leaching mechanism of the elements that contained in the artificial rock is the diffusion mechanism. Therefore, the primary leaching model is obtained, and thus the chemical stability of the mineral has been verified.Then the artificial rock ceramic solidification body is synthesized successfully by through cordierite as raw materials substitute for actinides high waste at 1200 oC for 2h, subsequently the spectrophotometry was employed to test the normalized leaching rate of Ce(IV), the magnitude of which is 10-6~10-5 and the tested method for curing body soaking solution of cerium is created successfully. The results show that the leaching mechanism of cerium contained in the artificial rock solidified body is the dissolution mechanism in the short term.PHREEQC software was employed to study the distribution of uranium species based on the chemical composition of Beishan groundwater at length. The effects of pH, temperature and PE on the distribution of uranium species was calculated and discussed, and then analyzes the variation, which provides a theoretical basis and research ideas for the follow-up study of curing artificial rock. |
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