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

Abstract

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/(m2·a). After 3 000 years, the corrosion depth of the high-level glass solidified body with a length of 1 350 mm, a diameter of 440 mm, a mass of 400 kg and a surface area of 17 m2 is 1.62 mm. B, Re and Si release 12.24%, 10.41% and 0.18% of total element content, respectively.

Keywords

• fissure filling
• high-level glass solidified body
• beishan pre-selection area
• release of element