高放废物深地质处置中水泥基裂隙封闭材料的设计及服役行为研究

Deep geological repository based on a multi-barrier design approach is the most promising and feasible disposal method for high-level radioactive waste. In this project, according to the gene defect and the sealing technology bottlenecks of cement-based fracture sealing materials for deep geological repository (Abbr. GRCSM), the method of the nano-micron and reverse-agglomeration for cement particles based on the fracture sealing is investigated, and the preparation method and the characteristic parameters of the nano-micron cement is proposed. The design, regulation and preparation methods for GRCSM with low-pH, high flow and high durability are formed. The low-pH formation mechanism and microstructure model of GRCSM under the higher w/c condition are clarified. The theoretical framework of design, preparation and application of GRCSM with low-pH, high flow and high durability is constructed..The research results will not only lay a theoretical basis for the construction of preparation and application technology for GRCSM, but also provide the theoretical guidance and technical support for the construction of deep geological repository of high-level radioactive waste.

基于“多重屏障原理”的深地质处置法是最具前景的高放核废物终极处置方法。针对深地质处置工程水泥基裂隙封闭材料的基因缺陷和封闭工艺瓶颈，本项目基于颗粒整形、纳微米改性、粒度级配和密度梯度匹配及次第水化等技术，研究适用于岩石裂隙(隙宽100μm)封闭的水泥高效介纳微米化及反团聚方法，探讨大水灰比、无有机塑化剂和全纳微米颗粒条件下水泥基裂隙封闭材料的低pH、高流态化设计及其调控机制；研究水泥基裂隙封闭材料的水化动力学以及微结构形成机理；阐明深地质处置环境下水泥基裂隙封闭材料的服役行为及失效机理；在此基础上，形成较系统的高放废物深地质处置中兼具低pH、高流态、高稳定性和高耐久性的多功能水泥基裂隙封闭材料设计、制备及应用的理论框架。.项目研究成果将为构建高放废物深地质处置中水泥基裂隙封闭材料的制备及应用技术奠定理论基础，而且可为高放废物地质处置地下实验室和处置库的建设提供可借鉴的理论指导和技术支撑。

基于“多重屏障原理”的深地质处置法是最具前景的高放核废物终极处置方法。针对深地质处置工程水泥基裂隙封闭材料的基因缺陷和封闭工艺瓶颈，本项目采用超细水泥颗粒水化，大掺量辅助胶凝材料降低水泥基孔隙溶液pH值等手段，探讨大水灰比、无有机塑化剂和全纳微米颗粒条件下水泥基裂隙封闭材料的低pH、高流态化设计及其调控机制；制备出一种兼具低pH值，超高流态，高稳定性和高服役性的水泥基裂隙封闭材料，研究水泥基裂隙封闭材料的水化动力学以及微结构形成机理；模拟深地质处置环境下，裂隙水和温度对水泥基裂隙封闭材料的服役行为，探究了水泥基裂隙封闭材料与膨润土的相互作用，阐明深地质处置环境下水泥基裂隙封闭材料的服役行为及失效机理。 .项目研究成果将为构建高放废物深地质处置中水泥基裂隙封闭材料的制备及应用技术奠定理论基础，而且可为高放废物地质处置地下实验室和处置库的建设提供可借鉴的理论指导和技术支撑。