建造用于含水层中核素迁移试验的地下研究设施的技术要求

在中国辐射防护研究院 (CIRP)野外试验场建造了用于在浅部含水层中进行核素 (2 3 7Np、2 3 8Pu、2 41Am和 90 Sr等 )迁移试验的地下研究设施 (URF)。该设施须满足的主要技术要求包括 :保持周围试验区土体结构稳定 ,保持地下水化学条件和水动力条件不被改变。采用人工小进尺开挖和快速支护衬砌以及沉井法建造竖井等措施保护了周围土体结构未被破坏。衬砌前用四层聚乙烯膜铺衬洞壁 ,竖井体下沉前外壁涂刷氯烯烃防水胶液 ,基本防止了对地下水化学条件的影响。严格控制施工降水方式 ,由于施工中未采用抽水降低水位方式 ,保持了地下水动力条件没有变化。施工和运行过程中对有关指标进行了监测 ,结果表明采取有效措施后使 URF达到了预定技术要求 ,满足了核素迁移试验条件

TECHNICAL REQUIREMENTS FOR CONSTRUCTION OF UNDERGROUND RESEARCH FACILITY USED FOR NUCLIDE MIGRATION TEST IN AQUIFER

An underground research facility (URF) for nuclide migration test in shallow aquifer has been constructed in the field test site of China Institute for Radiation Protection. The URF has to meet the following main technical requirements: no disturbance to soils in the experimental area, keeping original state of groundwater table and chemical conditions of groundwater unchanged. Making use of small scale excuvation by man power and quick lining operation for the gallery and vaults, and sinking work for the shaft, the original soil structure in the surroundings was protected from damage before loosing. Four layers of polyethylene film as waterproof materials are applied to the wall of gallery, vaults before lining and the outer wall of the experimental shaft is coated with alkenyl chloride gum coating material, so that the groundwater chemical conditions were not changed. Because no other drainage was adopted to dis elevate the watertable, the original groundwater dynamic conditions were kept unchangeable. During URF construction and operation some detections were carried out. The results express that by use of effective measures the URF has met the technical requirements and the conditions for nuclide migration test.$$$$(