Research On Radiation Effects Of α-decay On HLW Glasses

In recent years, China began to develop its nuclear energy industry, which will produce a large number of nuclear wastes that needs to be isolated from the Biosphere and disposed permanently. According to the plan of Chinese Government, the high-level liquid waste, which was produced in the post-processing stage of the spent fuel generated by the nuclear power industry, will be solidified in glass and then disposed in the deep geological repository. To predict the behaviors of HLW glass in geological repository, to prevent possible leakage of radionuclides, it is necessary to understand the long-term radiation effect of the HLW glass.The radiation effects of HLW glass caused by a-decay were discussed and researched. First, the characteristics of radiation sources and radiation of HLW glass were described in this thesis. And then, microcosmic, microscopic and macrocosmic damages caused by radiation on the HLW glass were discussed. Experiment and simulation methods used in other researches'on radiation effects of HLW glass were compared and the most appropriate method for this study (charged particle irradiation) was point out.Research works of this thesis were carried out by irradiation with Xe ions and Protons respectively. Feasibility of simulating the effects of a-particle irradiation with proton irradiation was discussed, and fundamentals and structure of the tandem accelerator used for proton radiation were described, with emphasis on the tandem accelerator used in the experimental work of this thesis as well as the irradiating process. Also the feasibility of simulating a-recoil particles with Xe ions irradiation was demonstrated. The 320kV high voltage platform which was used for Xe ions irradiation, especially the ECR ion source in it was introduced in details, and the experimental process also was described. In addition, irradiated samples were tested by Raman spectroscopy and Nano-hardness tester, both of which were demonstrated.According to the analysis on Raman spectrum and Nano-hardness results of Proton irradiated samples, bridge oxygen in the radiated samples was found decreased, no bubbles were found and Nono-hardness increased. Compared with other research's results, the possible reasons of these phenomena were discussed. With the analysis on the Raman spectrum and Nano-hardness results of Xe ions irradiated samples, the limitation of Raman test was discussed as well as the reasons of the Nano-hardness decreasing. At last, point out how to select the glass used for HLW.