平地型铀尾矿库氡大气扩散数值模拟及环境效应分析  

Numerical simulation of atmospheric diffusion of radon emitted from ground uranium tailings impoundment and environmental effects

作　　者：刘振昊[1] 彭小勇[1] 熊军[1] 万芬[1] 谢清芳[1] 

机构地区：[1]南华大学城市建设学院,湖南衡阳421001

出　　处：《安全与环境学报》2012年第3期93-96,共4页Journal of Safety and Environment

基　　金：国家自然科学基金项目(11075072)

摘　　要：以平地型铀尾矿库为研究对象,采用数值模拟方法,分析了铀尾矿库下风向的氡扩散和浓度分布,并预测了该地区常年主导风向下氡对公众所致的年有效剂量。结果表明,风速从0.5 m/s变化到2.0m/s时,氡在尾矿库下风向的积聚范围由5 000 m缩减为2 500 m,尾矿库下风向2 500 m距离以内的氡浓度降低较快,随着距离的增大,近地面区域氡浓度不断降低,5 000 m外氡浓度变化渐趋平缓。U10=0.5m/s时尾矿库下风向地区的氡浓度比其他风速下最高高出近43%。对照公众个人的年有效剂量标准,考虑风频风速影响,对氡的环境效应分析表明,低风速下现行标准中铀尾矿库防护距离的规定值偏小,应进行适当调整。The article attempts to introduce a numerical simulation model of atmospheric diffusion of radon emitted from ground tailings impoundment and analyze environmental effects.The results of our simulation show that radon concentration tends to decrease continually and turn to be smaller with the increase of the air speed and the defusing distance.When U10=0.5 m/s,the accumulated radon would defuse at the downwind area within the maximum distance of 5 000 m.And,when the air speed increased to U10=2.0 m/s,the range would reduce to 2 500 m in the same downwind area.As a result,the local pollution would become serious.However,if the air speed tends to increase,the radon diffusion and pollution would spread farther and the pollution the area suffers tends to be slighter.When U10=0.5 m/s,the radon concentration of the tailings at the downwind area would be 43% higher than the highest radon concentration under other air speeds.Thus,it can be seen that the air speed may have a great effect on radon diffusion.The regulations of radon radiation and environmental protection in uranium mining and milling（GB 23727—2009） area suggest that the distance between the tailings boundary and the residential area should be separated at least no less than 800 m,which can be tested by using the annual effective dose of the public evaluation for its surrounding effect.The analysis of the annual effective dose caused by the radon tailings at the downwind area shows that there exists a great relation between the protection distance of tailings and the local air speed.When U10=0.5 m/s,f=12.6%,the protection distance of the tailings impoundment should be greater than that of standard distance under the circumstance of the prevailing wind direction and the wind frequency.But,when U10=1.0 m/s,1.5 m/s,2.0 m/s,the protection distance of the tailings can be made within 800 m.In addition,there also exists very close relation between the protection distance of tailings and the local air speed and frequency.When the air speed is smaller and the w

关 键 词：环境工程学 铀尾矿库 数值模拟 大气扩散 环境效应 

分 类 号：TL752.2[核科学技术—辐射防护及环境保护] X34[环境科学与工程—环境工程]