Comparative studies of irradiation effects in borosilicate glass and fused silica irradiated by energetic Xe ions

摘要

As the first safety barrier of high level radioactive waste, the tolerance to radiation of vitrification is critical. Vitrification is a kind of specialized glass used as the package of high-level radioactive waste in nuclear power industry. Because of its structural consistency with the main structure of vitrification (silicon-oxygen tetrahedron), fused silica is used to study the irradiation effect on network of vitrification in the present study. Borosilicate glass, a simplified version of vitrification, is studied under the same conditions for comparison. Hardness values, moduli and refractive indexes of fused silica and borosilicate glass are measured before and after irradiation with nanoindentation technology and elliptic polarization instrument. It is shown in this study that the hardness values of fused silica and borosilicate glass decrease with increasing dose. On the other hand, with dose increasing, the modulus of borosilicate glass decreases but the modulus of silica increases. Change in modulus might be attributed to the change of density, which is consistent with results from the refractive index.