Numerical Simulation On The Atmospheric Migration Of Particles Of Uranium Tailings Impoundment And Environmental Effect

The uranium mines produced a large amount of waste rocks and tailings in the miningand smelting process, which was piled up in the tailings impoundment. About dozens ofradionuclide was contained in uranium tailings impoundment, and fine particulate matter(tail ore) in the beach face of uranium tailings impoundment would migrate under theaction of wind, water and other natural factors. These radioactive particles would migratewith the atmosphere and subside to far away from the tailings area, and has a cumulativeeffect, which severely impairs the ecological environment of surrounding area, water andhealth. Therefore, studying the law of migration, sedimentation and distribution of uraniumtailings particles in the atmosphere is an important topic of radiation protection andenvironmental evaluation during the running of uranium tailings impoundment.Thesis was one of the topics of the national natural science fund project（11075072）,which was named“the study on uranium tailings soil-vegetation-coupledatmospheric diffusion model of atmospheric nuclide and numerical simulation”. Based onground type uranium tailings of different weather conditions such as wind speed, winddirection and wind frequency, using numerical simulation method studied the motiontrajectory, concentration distribution of different diameter particles in the beach face ofuranium tailings impoundment, the particulate scope of annual deposition amount,distribution and environmental effect, as well as some corresponding protective measureswas provided.The main research contents contain several aspects:（1）Described the characteristics of radioactive particles, their hazards and models ofparticles with the atmosphere and analyzed the major factors that influenced migration anddeposition of particles in the uranium tailings.（2）Based on CFD and the discrete phase model of particle migration, setting up the mathematical model of the atmospheric boundary layer wind field and determined thenumerical calculation method about particles in the atmospheric migration.（3）Based on ground type uranium tailings, using numerical simulation methodstudied the motion trajectory, concentration distribution and the scope of annual deposition,and revealed the law of migration and sedimentation of uranium tailings particles in theatmosphere under the condition of various factors.（4）Based on the simulation results, calculate under different wind directions theannual deposition amount of radioactive particles in tailings downwind direction, analyzeits harm to the environment and propose precautions to prevent the pollution of radioactiveparticles in uranium tailings impoundment.