Attack of superoritical fluid on nano-scale indented zones of rocks and minerals

点击翻译按钮获取中文摘要

We confirmed that the supercritical H20 generator can generate temperature of up to 550. C and pressure of up to 40 MPa. Then, dissolution test of indented quartz single crystal was performed in the temperature and pressure range. The size of indented imprints on quartz single crystal were rapidly dissolved when the H2O was in supercrical. The similar test for silica glass shows that the glass was dissolved at much faster rate than quartz single crystal.From the above result, we tentatively propose that the level of the nuclear geological waste is better not to be deeper than 600 m. If the depth is more than the critical one and if the extraordinary heat is accidentally supplied from the waste, H2O at the neighbour of the waste may become supercritical to dissolve much amount of minerals and rocks there. We also propose that the single crystal of quartz is much better to use the confining material of the high-level nuclear waste than the silica glass, because it is more resistant against supercritical fluid.