The migration of the uranium (U) in high-level radioactive waste that is held in deep geological repositories via fractures in deep granite aquifers is a serious safety concern, thus, this study investigates the effect of fracture filling materials designed to mitigate these concerns. Geochemical analysis was conducted on granite rock core and groundwater samples collected from boreholes located in granite areas. Sequential extraction tests on fracture filling material (FFM) samples were also conducted. The rock core samples were classified as two-mica granite that had uranium (U) content ranging from 1900 to 22,100 μg/kg with an arithmetic mean of 8500 μg/kg. The total U concentration in the FFM samples was found to range from 790 to 80,781 μg/kg. The U in the FFM samples was mainly associated with a carbonate phase that made up from 29.9 to 100% of the total U in the FFM. The U fraction of carbonate phase was closely correlated with the Ca fraction. U associated with crystalline inorganic FFM constituents (e.g, clay minerals and metal oxyhydroxides) was also found in FFM samples in fractions ranging from 21.1 to 70.1%. U in FFM is mainly incorporated via Ca-carbonate, which might have not been formed in modern groundwater, but the time and temperature during formation are unknown. In addition, the Fe, Si, Al, Ca, K, and U levels were found to be well correlated with each other, suggesting that U can also become geochemically associated with crystalline clay minerals or Fe-oxyhydroxides.

铀（U）在深部地质库中的高放射性废物中的迁移通过花岗岩深层含水层中的裂缝是一个严重的安全问题，因此，本研究调查了旨在减轻这些问题的裂缝填充材料的影响。对花岗岩岩心和从位于花岗岩区域的钻孔中收集的地下水样品进行了地球化学分析。还对裂缝填充材料（FFM）样品进行了顺序提取测试。岩心样品被分类为铀含量在1900至22,100μg/ kg之间的算术平均值为8500μg/ kg的两云母花岗岩。结果表明，FFM样品中的总U浓度为790至80,781μg/ kg。FFM样品中的U主要与由29个碳酸盐组成的碳酸盐相有关。在FFM中占总U的9％到100％。碳酸盐相的U分数与Ca分数密切相关。在FFM样品中还发现与结晶性无机FFM成分（例如粘土矿物和金属羟基氧化物）相关的U含量范围为21.1％至70.1％。FFM中的U主要通过碳酸钙掺入，碳酸钙可能不是在现代地下水中形成的，但形成过程中的时间和温度尚不清楚。另外，发现Fe，Si，Al，Ca，K和U含量之间具有很好的相关性，这表明U也可能与结晶黏土矿物或羟基氧化铁发生地球化学联系。在FFM样品中也发现了粘土矿物和金属羟基氧化物），含量范围为21.1％至70.1％。FFM中的U主要通过碳酸钙掺入，碳酸钙可能不是在现代地下水中形成的，但形成过程中的时间和温度尚不清楚。另外，发现Fe，Si，Al，Ca，K和U含量之间具有很好的相关性，这表明U也可能与结晶黏土矿物或羟基氧化铁发生地球化学联系。在FFM样品中也发现了粘土矿物和金属羟基氧化物），含量范围为21.1％至70.1％。FFM中的U主要通过碳酸钙掺入，碳酸钙可能不是在现代地下水中形成的，但形成过程中的时间和温度尚不清楚。另外，发现Fe，Si，Al，Ca，K和U含量之间具有很好的相关性，这表明U也可能与结晶黏土矿物或羟基氧化铁发生地球化学联系。