某铀矿山废石堆多层覆土治理效果实验研究  

Experimental Study on Treatment Effect of a Uranium MineWaste Rock Piles by Covering Multilayer Soils

作　　者：李娜娜[1,2] LI Nana(Beijing Research Institute of Uranium Geology,Beijing 100029,China;CAEA Innovation Center for Geological Disposal of High-Level Radioactive Waste,Beijing 100029,China)

机构地区：[1]核工业北京地质研究院,北京100029 [2]中国国家原子能机构高放废物地质处置创新中心,北京100029

出　　处：《世界核地质科学》2023年第4期1044-1055,共12页World Nuclear Geoscience

摘　　要：覆土抑氡是铀矿山废石堆退役治理的重要手段之一,但在实际工程应用中面临一系列挑战,特别是那些位于深山峡谷、机械难以到达的废石堆,土壤的大规模运输和机械压实都很难实现。为解决这一难题,以江西省某铀矿山废石堆为研究对象,以膨润土和黄土作为覆土材料,开展了多层覆土实验,获取了不同压实度和不同覆土厚度3种覆土方案下,废石堆表面氡析出率和伽马辐射剂量率的变化情况,研究了覆盖层厚度与氡析出率的关系。实验结果表明:3种覆土方案均能有效降低氡析出率和伽马辐射剂量率水平,达到了氡析出率低于0.74 Bq⋅m^(-2)·s^(-1)的管理限值;通过对比分析3种方案实验数据,提出了抑制废石堆表面氡析出率的多层覆盖优选方案。研究结果对铀矿山废石堆治理现场施工方案的确定具有一定的参考价值和指导意义。Covering soil is one of important measures to restrain radon for decommissioning uranium mines.However,there are some waste rock piles which are located in the deep mountain canyon,stacked along the mountain and could not be reached by machines in engineering practice,which results in the difficulty to realize mass soil transportation and mechanical compaction.In order to solve this problem,a uranium mine waste rock in Jiangxi province was taken as research object,the multilayer covering experiments were carried out by using bentonite and loess as covering materials.Radon exhalation rate and gamma penetrating radiation dose rate of waste rock piles surface were investigated under different compactness and covering thickness.The relationship of covering thickness and radon exhalation rate was revealed.The results showed that three covering schemes could reduce radon exhalation rate and gamma penetrating radiation dose rate effectively,whose reducing radon exhalation rate effects could meet the requirement of authorized limit of 0.74 Bq⋅m^(-2)⋅s^(-1).A preferred covering scheme to restrain radon exhalation rate of this type of waste rock piles surface was proposed through analyzing experimental data of three schemes at last.All the results have certain reference value and guiding significance to determine onsite construction plan of waste rock piles treatment.

关 键 词：膨润土 多层覆土材料 氡析出率 废石堆 压实度 

分 类 号：TL943[核科学技术—辐射防护及环境保护]