【摘要】 如何安全处置高放废物是核工业可持续发展面临的挑战性问题。我国的高放废物深地质 处置研究从1985年开始,提出的计划目标是:于21世纪中叶建成我国高放废物地质处置库,处置的 对象是玻璃固化块、超铀废物和部分乏燃料,处置库为竖井-坑道型,候选围岩为花岗岩,位于饱和 带中。在1985~2004的20a中,我国高放废物地质处置研究取得了进展,已确定我国高放废物最终 处置走"深地质处置",并且是"三步曲"式的技术路线,即处置库选址和场址评价-地下实验室- 处置库。经过全国筛选对比,已初步选定甘肃北山地区为重点预选区,该区地处戈壁,地壳结构完 整,地壳稳定,人烟稀少,地质条件和水文地质条件均有利。20世纪90年代初期,开展了地下实验 室的选址工作,初步选择了北京郊区2处地点为我国高放废物地质处置"普通地下实验室"的场址。 已确定使用膨润土作为处置库的回填材料,并初步确定内蒙古高庙子膨润土为我国高放废物处置库的 首选缓冲回填材料。对膨润土的矿物学、岩土力学、物理力学性质和热学性质进行了研究。已获得一 批放射性核素(主要是Np、Pu、Tc)在北山花岗岩和膨润土上的吸附分配比、扩散系数和弥散系数 等参数,建立了低氧手套箱和模拟处置库温度、压力和氧化-还原条件的小型实验装置。高放废物中 的关键核素的更多还原

【Abstract】 Safe disposal of high level radioactive waste (HLW) is a challenging issue for the sustainable development of nuclear energy. The studies for the disposal of HLW in China started in 1985, the proposed goal was to build China’s high level waste repository by mid-21st Century, while the waste to be disposed of will be vitrified waste, transuranic waste and small amount of spent fuel. The proposed repository was a shaft-tunnel-silo model hosted by granite in saturated zone. In the period of 1985 to 2004, progress was made in China’s HLW disposal program. It was decided that "deep geological disposal" will be used to dispose of China s HLW, while the technical strategy for the development of repository will a 3-step strategy, that includes steps of site selection & site evaluation, construction of underground research laboratory, and construction of repository. Based on nation wide screening, the Beishan area, Cansu Province, northwestern China, located in Gobi desert area with few inhabitants, integral crust structure and favorable geological and hydrogeological conditions, was selected as the most potential area for China s repository. In early 1990 s, site selection for underground research laboratory was conducted, 2 sites in the suburb of Beijing were preliminarily selected as the potential sites for a " generic underground research laboratory" . It was determined to use bentonite as backfill material for the repository, while the bentonite from Gaomiaozi deposit in Inner Mongolia was selected as potential buffer and backfill material for China s repository. The studies on the mineralogical, geotechnical, physico-mechanical and thermal properties of the Gaomiaozi bentonite have been conducting. Some parameters such as sorption radio, diffusion coefficient and dispersion coefficient of radionuchdes (Np, Pu and Tc) in Beishan granite and bentonite have been obtained. A low-oxygen glove box and a device simulating the temperature, pressure and redox potential of repository have been established. China has also made progress in the studies of the chemical behaviour of some key radionuclides. Significant results obtained in natural analog studies such as radionuclide migration near the contact zone between granitic intrusions, transuranic radionuclide migration in uranium deposits, and corrosion of bronze ware. Literature investigations of source term codes, biosphere codes and total system performance assessment codes have been conducted. Conceptual design was only conducted in early 1990’s. Since 1999, 2 technical cooperation projects with the International Atomic Energy Agency in the field of high level radioactive waste disposal have been conducting, which greatly enhanced our technical ability. All the technical researches during 1985 - 2004 provide good basis to fulfill the goal of constructing China’s HLW repository in the middle of 21st century.更多还原