摘要
极低放填埋场防渗层设置是阻滞放射性核素进入生态环境的重要工程措施,开展防渗层的阻滞性能研究对于防渗层的设计和环境安全评价具有重要意义。针对来源废物中的主要核素^(60)Co和^(63)Ni,采用静态吸附实验和柱迁移实验获得了场址粘土的饱和渗透系数、分配系数及弥散度等特征参数,并通过数学模型预测了核素穿透防渗层后的浓度变化。结果表明,Co、Ni的分配系数分别为140.92 m L·g^(-1)和380.43 m L·g^(-1),阻滞因子分别为859和2 317,表明场址粘土对^(60)Co、^(63)Ni具有较强的阻滞性能;在防渗层正常发挥功能的情景下,防渗层渗出液中的^(60)Co、^(63)Ni浓度很低,用此类粘土建成的防渗层能够确保当地环境安全。
Background： Very low level waste （VLLW） landfill antiseepage layer is a key engineering measure to prevent the radioactive nuclides from entry into the surrounding environment. Purpose： This study aims to give an example of quickly evaluating the retardation capability of a VLLW antiseepage. Methods： The landfill soil＇s distribution coefficient （Kd）, saturated permeability coefficient （Ks） and dispersion coefficient （D） were got by batch test and column migration test, and the concentration of nuclides through antiseepage layer was calculated with the advection dispersion equation. Results： The results showed that the Kd of Co and Ni were 140.92 mL.g^-1 and 380.43 mL.g^-1, respectively, and retardation factors （Rd） of Co and Ni were 859 and 2 317, respectively, which means this soil has a very strong retardation capacity for Co and Ni. In addition, the breakthrough concentrations of Co and Ni by calculation under the normal circumstance were very low. Conclusion： So the antiseepage layer using this site soil can effectively ensure the environment safety.
出处
《核技术》
CAS
CSCD
北大核心
2017年第3期39-45,共7页
Nuclear Techniques
基金
国家自然科学基金(No.21577133)资助~~
