遵义镍钼矿区、遵义城区公众剂量估算与评价

【作者】 马光鼐；

【导师】 肖德涛； 王达清；

【作者基本信息】 南华大学 ， 核能与核技术工程， 2010， 硕士

【摘要】 遵义镍钼矿是典型的放射性镍钼铀伴生矿,也是贵州省近期集中开采的伴生矿之一。随着采矿、选矿、冶炼过程,天然放射性核素在物料及产品中进行了再分布,通过工业“三废”排入环境,导致天然放射性核素及其衰变子体向环境释放,在局部引起较高的天然放射性物质浓度及其照射水平。本文采用现场监测以及结合贵州省辐射环境监理站历年监测的方法,获得了遵义矿区和遵义城区大量的调查数据,如土壤、大气、水体中天然放射性核素的含量及其分布,并对该地区公众各项生活指标进行调查分析,对可能受辐射影响的各类人群进行分类,估算其受照剂量水平,得出以下结论:土壤中的污染核素为铀,主要分布于浅层地表5～20cm范围内,最高达到234.80Bq/kg。污染源附近工作的人员所受外照射年有效剂量为0.68mSv,明显高于天然辐射源地面γ辐射所致全国平均水平0.48mSv和世界平均水平0.54mSv;遵义镍钼矿区、遵义城区公众年总有效剂量(均为除去了宇宙射线的贡献)为0.41～39.31mSv,镍钼矿区公众年总有效剂量高于我国天然辐射源除去了宇宙射线的贡献后所致平均辐射剂量水平1.98mSv,也高于世界天然辐射源除去了宇宙射线的贡献后所致平均辐射剂量水平2.02mSv;遵义镍钼矿区、遵义城区公众吸入氡及其子体所致吸入内照射占总剂量份额的58.50%～84.94%,大部分是世界平均水平62%的1～1.37倍,说明遵义镍钼矿区、遵义城区公众年有效剂量的增高主要是由于氡及其子体引起的。此外,根据调查与分析结果本文也提出了一系列的切实可行的放射性污染防治措施。更多还原

【Abstract】 Zunyi nickel-molybdenum mine is a typical associated mine which contains nickel,molybdenum and uranium, and is an important mine which is being exploited activtvely in Guizhou province. Natural radiation nuclides are distributed again following mining, beneficiation and smelting. The nuclides and their progeny are released into the local environment together with three industrial wastes, so as to increase concentration of radionuclide and radiation level.The research data was gained by the site monitoring and reviewing past records of environmental monitoring of radiation of Guizhou province, such as the level of natural radionuclide in soil, air, water and their distribution. The life index of the public was investigated and analyzed. The public was classified with the radiation effect and the dose was estimated. The following conclusions: Uranium is the most important nuclide for soil pollution and is mainly distributed at the shallow soil above 20cm. Radon and its progeny are the main radiation sources in atmosphere. The annual effective dose of worker is 0.68mSv,from external exposure in mine. It exceeds markedly the mean dose of nationwide from natural gamma radiation(about 0.48mSv) and international dose from natural gamma radiation(about 0.54mSv).The total annual effective dose is 0.41～39.31mSv for the public of Zunyi nickel-molybdenum mine and Zunyi city. The results of mine exceed the natural radiation dose of nationwide(1.98mSv) except cosmic rays, also exceed the international value(2.02mSv).The internal radiation dose account for 58.50%～84.94% in the total annual effective dose from radon and its progeny, and mostly exceed international value(62%). It is obvious that the raising of the total annual effective dose is attributed to radon and its progeny.In addition, a series of practical pollution control measures are also proposed according to the investigated and analyzed results in this article.更多还原