大亚湾废物处置场中工程地球化学屏障的研究

Study into Engineering Geochemistry Barrier in Dayawan Wastes Disposal Site

根据地球化学障原理,探讨了将人工工程地球化学屏障应用于广东大亚湾放射性废物处置场的可行性.针对当地“酸性-氧化”水土条件,以核素235U,60Co,90Sr为研究对象,进行了一系列静态模拟实验和动态淋滤柱模拟实验,测定了分配系数K、核素浓度随时间与迁移距离的变化,实验结果表明,Na2S作为主要添加剂建立的“碱性-还原”工程地球化学屏障,对阻滞核素235U,60Co,90Sr迁移非常有效,不仅能显著改善土体地球化学条件,而且能降低土体的渗透性能,人工工程地球化学屏障是一项经济、简便、实用的工程技术.

Based on the principle of geochemistry barrier, the feasibility of artificial engineering geochemistry barrier is discussed which, has been applied in Dayawan radioactive wastes disposal site in Guangdong province China. According to the native water and soil condition of 'acidic-oxidation ', a series of static simulation experiments and dynamic filtering pole simulation experiments were carried out and the distribution coefficient (K) and concentration of nuclides were measured along with time and transference distance. The result shows that the 'alkalescence and deoxidation' engineering geochemistry barrier using Na2S as main additive can efficiently retard the nuclide transference, which can not only notably improve geochemistry conditions of soil but also greatly reduce permeability of soil. Artificial engineering geochemistry barrier is an economical, simple, and practical engineering technique.