围岩水中玻璃体关键元素动态浸出特性研究

Dynamic Leaching Characteristics of Key Elements in Glass Solidified Body in Surrounding Rock Water

为了获得地下水侵入深部围岩裂隙所致高放玻璃固化体核素释出与迁移参数的变化规律,本研究以高放玻璃固化体中核素在石英石水岩饱和水中的迁移行为为研究对象,开展了动态浸出试验,重点分析研究了元素B、Re和Si在浸出液中的浓度变化以及玻璃的腐蚀情况。结果显示,动态浸出试验150 d后,离子浓度均随反应时间的增加而增大。反应温度为90℃时,地质处置库中流速为40 L/(m^(2)·a)的石英石水岩饱和水中,玻璃柱的腐蚀速率为540 nm/a,3000年后,长1350 mm、直径440 mm、质量400 kg、表面积17 m^(2)的玻璃柱腐蚀深度为1.62 mm,B、Re和Si分别释出元素总含量的12.24%、10.41%和0.18%。

During the construction stage of the repository,excavation redistributes the stress in the surrounding rock,causes disturbance in the surrounding rock,expands and connects the primary cracks in the rock mass,generates new micro-cracks,increases the permeability coefficient of the rock mass,and causes changes in the composition of groundwater flowing through the deep cracks in the surrounding rock mass,thus affecting the release and migration parameters of nuclides in the glass solidified body.Studies on the effects of multiple barrier media on the release of nuclides were carried out both at home and abroad,and valuable original data were obtained,but there is a lack of studies on the effects of rock fissure fillings on the release of nuclides.In order to obtain the change rule of nuclide release and migration parameters in high-level glass solidified body caused by groundwater intrusion into deep surrounding rock cracks,the migration behavior of nuclide in high-level glass solidified body in saturated water of quartz rock was taken as the research object,the dynamic leaching test was carried out,and the concentration changes of elements B,Re and Si in the leaching solution and the corrosion of high-level glass solidified body were focused.The results show that after 150 days of dynamic leaching test,the ion concentration increases with the increase of reaction time,and the element dissolution in high-level glass solidified body shows identity.Through the formula calculation it can be obtained that the order of the normalized leaching rate is NR(B)>NR(Si)>NR(Re),and the order of the normalized weight loss rate is NL(B)>NL(Si)>NL(Re).When the reaction temperature is 90℃,the corrosion rate of the high-level glass solidified body in the geological repository is 540 nm/a with the flow rate of 40 L/(m^(2)·a).After 3000 years,the corrosion depth of the high-level glass solidified body with a length of 1350 mm,a diameter of 440 mm,a mass of 400 kg and a surface area of 17 m^(2)is 1.62 mm.B,Re and Si release 12.24%,10.41%and 0.18%of total element content,respectively.