铀自燃对放射性气溶胶的影响研究

Research on Effect of Uranium Pyrophoricity on Radioactive Aerosol Changes

以国内某金属铀真空蒸镀实验室的金属铀物料加工工艺为对象,采用放射性气溶胶连续监测,向心式气溶胶粒度分级采样,垂直高度分级采样等方法,研究了金属铀自燃对实验室空气中放射性气溶胶浓度、粒径分布、空间竖直分布的影响。结果表明,金属铀自燃明显提高了实验室空气中放射性气溶胶的浓度;所产生的气溶胶活度中位直径为9.89μm,粒径分布中大粒径气溶胶粒子占优;燃烧产生的放射性气溶胶在物料高度处浓度的增大水平高于工作人员呼吸带的增大水平。

This paper bases on Uranium machining and treatment process of a domestic laboratory for Uranium vacuum evaporation, use radioactive aerosol continuous monitoring, centripetal aerosol size grading sampling, vertical hierarchical aerosol sampling and other method, studies on effect of Uranium pyrophoricity on radioactive aerosol concentration, size distribution and vertical distribution changes in laboratory. The results shows that the concentration of radioactive aerosol significantly increased while Uranium self-ignition, the activity median diameter of radioactive aerosol with metallic Uranium self-ignition is 9.89 μm, large size particles is dominant in aerosol size distribution. In the burning material height aerosol concentration increasing is higher than the level of staff breathing zone increasing while Uranium self-ignition.