Influences of specific ions in groundwater on concrete degradation in subsurface engineered barrier system.
Influences of specific ions in groundwater on concrete degradation in subsurface engineered barrier system.
复制标题
DOI：
10.1186/s40064-016-2495-8
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Li MH
中科院分区：
文献类型：
--
作者：
Lin WS;Liu CW;Li MH
许多处置概念目前表明，混凝土是一种有效的限制材料，用于工程屏障系统（EBS）在一些低放射性废物（LLW）处置场。水泥基材料具有封装、隔离或阻滞各种有害污染物的特性。应用HYDROGEOCHEM 5.0的反应性化学传输模型，模拟水文地球化学过程对EBS混凝土屏障退化的影响，EBS已被提议用于台湾的低放废物处置场。模拟结果表明，引起混凝土劣化的主要过程是氢离子、硫酸盐和氯离子引起的物种。EBS与侧沟排水系统有效地排出渗透水，并降低可能导致混凝土退化的溶质浓度。氧化还原过程显著影响降解材料的形成。EBS中的还原环境减少了混凝土降解过程中钙矾石的形成。此外，混凝土屏障中的化学条件在拟议的低放废物处置库中300年后仍保持碱性。本研究提供了一个详细的长期演变的水文地球化学环境在台湾拟议的低放废物处置场。
Many disposal concepts currently show that concrete is an effective confinement material used in engineered barrier systems (EBS) at a number of low-level radioactive waste (LLW) disposal sites. Cement-based materials have properties for the encapsulation, isolation, or retardation of a variety of hazardous contaminants. The reactive chemical transport model of HYDROGEOCHEM 5.0 was applied to simulate the effect of hydrogeochemical processes on concrete barrier degradation in an EBS which has been proposed to use in the LLW disposal site in Taiwan. The simulated results indicated that the main processes that are responsible for concrete degradation are the species induced from hydrogen ion, sulfate, and chloride. The EBS with the side ditch drainage system effectively discharges the infiltrated water and lowers the solute concentrations that may induce concrete degradation. The redox processes markedly influence the formations of the degradation materials. The reductive environment in the EBS reduces the formation of ettringite in concrete degradation processes. Moreover, the chemical conditions in the concrete barriers maintain an alkaline condition after 300 years in the proposed LLW repository. This study provides a detailed picture of the long-term evolution of the hydrogeochemical environment in the proposed LLW disposal site in Taiwan.