地浸铀矿山终采区地下水中铀的自然衰减数值模拟预测  

Numerical Simulation Prediction of Natural Attenuation of Groundwater Uranium in a Post-mining Area at an In-situ Leaching Uranium Mine

作　　者：杨冰 孟童 张昊岩 连国玺 李梦姣 YANG Bing;MENG Tong;ZHANG Haoyan;LIAN Guoxi;LI Mengjiao(The Fourth Research and Design Engineering Corporation,CNNC,Shijiazhuang 050021,China;School of Environment,Beijing Normal University,Beijing 100875,China)

机构地区：[1]中核第四研究设计工程有限公司,河北石家庄050021 [2]北京师范大学环境学院,北京100875

出　　处：《铀矿冶》2025年第1期93-100,共8页Uranium Mining and Metallurgy

基　　金：国家自然科学基金面上项目(CO_(2)+O_(2)地浸铀矿山退役采区地下水铀的生物地球化学过程及反应运移机理,项目编号42072273)。

摘　　要：地浸铀矿山终采区地下水环境修复问题是社会各界关注的焦点,当前对地浸终采区地下水U浓度的长期变化情况尚不清楚。综合利用野外调查及数值模拟方法,以中国北方某“CO_(2)+O_(2)”地浸铀矿山典型终采区为研究对象,在识别终采区地下水U分布特征的基础上,定量预测了不同时间地下水中U的自然衰减趋势,量化了U浓度在较长时间尺度上的变化情况。结果表明,终采区地下水中ρ(U)为0.273~5.24 mg/L,ρ(U)低于2.5 mg/L的取样点占比为64%;在地浸铀矿山终采后,地下水流向趋向于区域地下水的流向;当不考虑U自然衰减作用时,地下水中U在终采100年时可迁移至下游167 m处,预测迁移距离较保守;当考虑U的自然衰减作用时,终采100年时U的迁移距离仅为42 m,采区内地下水中的ρ(U)由模拟初始条件设置的2.5 mg/L降至1.0 mg/L。自然衰减作用可降低地浸终采区地下水中U的迁移距离和浓度水平,监控自然衰减技术(Monitored Natural Attenuation,MNA)可作为未来地浸铀矿山地下水修复的备选方案。The remediation of groundwater environment in the post-mining area at in-situ leaching uranium mines has aroused widespread public concern.The long-term change of groundwater U concentration in the post-mining area is still unclear.Field investigation and numerical simulation methods were comprehensively used in this study,and a typical post-mining area of a“CO_(2)+O_(2)”in-situ leaching uranium mine in northern China was taken as the research object.On the basis of identifying the distribution characteristics of groundwater U in the post-mining area,the natural attenuation trend of U in groundwater at different times was quantitatively predicted,and the long-term change of U concentration was quantified.The results show that the concentration of U in the groundwater in the post-mining area is 0.273~5.24 mg/L,and the sampling points with U concentration lower than 2.5 mg/L accounted for 64%.The simulation results show that in the post-mining stage,the groundwater flow direction tend to the regional groundwater flow direction.When the natural attenuation process of U is not considered,U in groundwater migrate to 167 m downstream after 100 years of final mining,and the predicted migration distance is conservative.When the natural attenuation of U is considered,the migration distance of U is only 42 m after 100 years of final mining.The concentration of U in the groundwater in the mining area is reduced from the initial 2.5 mg/L to below 1.0 mg/L.Natural attenuation can reduce the migration distance and the concentration of groundwater U in the post-mining area,and the monitored natural attenuation(MNA)technology can be used as an alternative scheme for groundwater remediation at in-situ leaching uranium mines in the future.

关 键 词：地浸铀矿山 监控自然衰减 地下水 铀 数值模拟 

分 类 号：TL212[核科学技术—核燃料循环与材料] X523[环境科学与工程—环境工程]