Abstract The changes in porosity caused by mineral dissolution/precipitation and the associated changes in flow, transport and chemical parameters of porous and fractured media are relevant for the geochemical time-evolution of natural and engineered underground systems. The realistic representation of natural systems requires modeling tools accounting for the changes in porosity. Here, we investigate the significance of the dynamic upgrade of the flow, transport and chemical parameters in reactive transport models with mineral dissolution/precipitation. The water flow, heat transfer and multicomponent reactive solute transport code, CORE2DV5, was extended to take into account the changes in porosity provoked by mineral dissolution/precipitation and their effect on flow, solute transport and chemical parameters. The improvements implemented in the code were verified against analytical solutions and the numerical solutions computed with other reactive transport codes with similar capabilities for isothermal mineral dissolution/precipitation test cases. Model results computed with CORE2DV5 agree with the analytical and numerical solutions for several isothermal test cases with porosity feedback. Model results show that failing to account for the porosity feedback leads to large errors. The porosity feedback effect (PFE) is especially relevant in long-term problems with mineral dissolution/precipitation leading to strong changes in porosity. The PFE is analysed with a non-isothermal geochemically-reactive transport model of the long-term (4·104 years) interactions of compacted bentonite with corrosion products and concrete in a high-level radioactive waste repository in clay. The model predicts pore clogging in the concrete and at the concrete-clay interface. The thickness of the zone affected by pore clogging computed with the PFE is smaller than that computed without the PFE.

中文翻译：

---

放射性废物处置库反应输运模拟中流动和输运参数的动态更新

摘要 矿物溶解/沉淀引起的孔隙度变化以及多孔和裂缝介质的流动、输运和化学参数的相关变化与自然和工程地下系统的地球化学时间演化有关。自然系统的真实表现需要建模工具来解释孔隙度的变化。在这里，我们研究了矿物溶解/沉淀反应输运模型中流动、输运和化学参数动态升级的重要性。水流、传热和多组分反应性溶质传输代码 CORE2DV5 被扩展以考虑由矿物溶解/沉淀引起的孔隙度变化及其对流动、溶质传输和化学参数的影响。代码中实施的改进已根据解析解和使用其他反应输运代码计算的数值解进行验证，这些代码具有类似的等温矿物溶解/沉淀测试案例能力。使用 CORE2DV5 计算的模型结果与具有孔隙度反馈的几个等温测试案例的解析和数值解一致。模型结果表明，不考虑孔隙度反馈会导致较大的误差。孔隙度反馈效应 (PFE) 与矿物溶解/沉淀导致孔隙度发生剧烈变化的长期问题尤其相关。PFE 使用非等温地球化学反应输运模型分析了压实膨润土与腐蚀产物和混凝土在粘土中的高放射性废物处置库中的长期（4·104 年）相互作用。该模型预测混凝土中和混凝土-粘土界面处的孔隙堵塞。使用 PFE 计算的受孔隙堵塞影响的区域的厚度小于未使用 PFE 计算的厚度。