毛细阻滞型覆土层对铀尾矿库氡析出影响的初步研究

尾矿库退役以后仍存在一定量的放射性危害.其主要危害物之—222Rn及其一系列的衰变子体.降低铀尾矿氡析出最常用的方法是覆盖.以往前人对覆盖降氡的研究大都没有考虑覆土层中毛细水的影响,但氡它一般不与其他物质发生化学反应,但能够溶于水.其本身又有自然衰变的性质且具有较短的半衰期.因此本文在土工实验的基础上,分析了覆土材料的级配组成.自制简易模型对多层覆盖系统的雨水渗流速度、分层含水率进行测试.研究发现多层覆土可延长渗流时间,交界处局部含水率略有提高.将气液两相流和氡的对流扩散理论引入铀尾矿覆土层氡迁移研究.建立了铀尾矿库覆土层氡浓度的预测模型.

A Preliminary Study on the Effect of Capillary Block Type of Soil Cover on Uranium Tailings Impoundment Radon Exhalation

Decommissioned tailings still exist after a certain amount of radioactive hazards. One of the main hazards series of 222Rn and its decay daughter. Uranium railings reduce radon exhalation most common method is to cover. Previous previous studies on radon reduction covering most of overburden layer without considering the impact of capillary water, but it generally does radon react chemically with other substances, but is able to dissolve in water. Natural decay of its own nature, and have a shorter half-life. This article, based on experiments in geotechnical analyzes overburden material gradation composition. Homemade simple model for multilayer cover system rainwater seepage velocity, layered moisture testing. Study found that multilayer soil percolation time may be extended, at the ）unction of the local moisture content increased slightly. The two-phase flow and convective diffusion theory into radon uranium tailings overburden radon migration studies. Establish a uranium tailings overburden radon concentration prediction model.