College of Construction Engineering, Jilin University, Changchun, 130026, China.
School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao, 266520, China.
Environ Sci Pollut Res Int. 2024 Jul;31(35):47899-47910. doi: 10.1007/s11356-024-34351-1. Epub 2024 Jul 16.
The distribution coefficient (K) of radionuclides is a crucial parameter in assessing the safety of high-level radioactive waste (HLW) geological repository. It is determined in the laboratory through batch and column experiments. However, differences in obtained K values from distinct experiments have not been thoroughly assessed and compared. This study evaluated strontium (Sr) sorption on different granite materials using static batch and dynamic experiments (column and core-flooding experiments). The results from batch sorption experiments showed higher Sr sorption on granite under acidic and strongly alkaline conditions, low solid-liquid ratios, and low ionic strength. In column experiments, a two-site sorption model was used to simulate Sr transport in crushed granite and mixed pure minerals. The sorption of Sr on crushed granite exhibited a higher affinity than that of mixed pure minerals. The dual-porosity transport model was employed to investigate Sr transport behavior in fractured granite in the core-flooding experiment. K obtained from batch sorption experiments are four to twenty times higher than those from column experiments, and two to three orders of magnitude higher than that from a core-flooding experiment. The results of this study provide valuable insights into safety assessment for the HLW geological repository.
放射性核素的分配系数（K）是评估高放废物（HLW）地质处置库安全性的关键参数。它可以通过批量和柱实验在实验室中确定。然而，不同实验中获得的 K 值之间的差异尚未得到彻底评估和比较。本研究使用静态批量和动态实验（柱和岩心驱替实验）评估了不同花岗岩材料对锶（Sr）的吸附。批量吸附实验的结果表明，在酸性和强碱性条件下、低固液比和低离子强度下，Sr 在花岗岩上的吸附更高。在柱实验中，使用双位点吸附模型模拟了 Sr 在破碎花岗岩和混合纯矿物中的运移。Sr 在破碎花岗岩上的吸附比混合纯矿物的吸附具有更高的亲和力。双孔隙度输运模型用于研究岩心驱替实验中裂隙花岗岩中 Sr 的输运行为。批量吸附实验中获得的 K 值比柱实验高 4 到 20 倍，比岩心驱替实验高 2 到 3 个数量级。本研究的结果为 HLW 地质处置库的安全评估提供了有价值的见解。
