铀矿区放射性核素氡在大气中的迁移研究  

Study of atmospheric migration of radon radionuclides at the uranium ore district

作　　者：王志勇[1,2] 刘畅荣[1] 王汉青[1] 周星火[3] 

机构地区：[1]湖南工业大学土木工程学院,湖南株洲412008 [2]中南大学能源科学与工程学院,长沙410083 [3]南华大学核资源与安全工程学院,湖南衡阳421001

出　　处：《安全与环境学报》2010年第3期103-106,共4页Journal of Safety and Environment

基　　金：国家自然科学基金项目(10775047)

摘　　要：以堆浸场、废石场为污染源项,对铀矿区大气中放射性核素氡在复杂地形条件下的迁移情况进行了模拟研究。结果表明,风速对山谷地形的氡气流场的分布影响比较明显。风速为1 rm/s时,在矿区内某居民点处没有涡流;当来流风速为2 rm/s和7 m/s时,产生了涡流,且涡流随风速的加快而加大。风速越大,污染物扩散越快,对居民点处的氡浓度的贡献越大。风速为1 m/s时,居民点处的氡浓度为5.4 Bq/m^3,2 m/s时6.5 Bq/m^3,7 m/s时达10 Bq/m^3。对铀矿区内某居民点处的氡浓度进行了实际测量,测量值与模拟结果吻合较好。The diffusion and migration of radon radionuclides is a critical issue in the fields of air pollution control and environmental management. It has been a great significance in environmental treatment and radiation safety protection to understand the migration principles of atmospheric radon at the uranium ore district. Heap leach field and waste rock dumps contain high level of radioactive nuclides and posses strong ability of radon exhalation which leads to certain degree of environment pollution. The exhaled radon from the heap leach field and waste rock dumps continuously drift, diffuse and eventually sink into the ground. Numerical simulation study on the migration principles of atmospheric radon over complex terrain is carried out by selecting heap leach field and waste rock dumps as airborne pollution sources. The results indicate that： （1） the influence of wind speed on flow field distribution of radon over the valley terrain is relatively significant. When the wind speed is 1 m/s, eddy current is absent at the residence area within the uranium ore district. The eddy current appears on the other hand when the wind speed increases to 2 m/s and 7 m/s. （2） The rate of pollutant diffusion is in linear relationship with the wind speed acceleration and thus contribute to the radon concentration at the residence area. When the wind speed is 1 m/s, the contribution of pollution sources to radon concentration at the residence area is 5.4 Bq/m^3. The concentrations become 5 Bq/m^3 and 10 Bq/m^3 when the wind speed increases up to 2 m/s and 7 m/s respectively. The measured radon concentrations agree well with simulation results, indicating that the numerical simulation can efficiently serve for prediction of the migration principle and concentration distribution of radon radionuclides over the complex terrain.

关 键 词：辐射防护技术 铀矿 氡 迁移 数值模拟 

分 类 号：X591[环境科学与工程—环境工程]