中文摘要：

基于核反冲理论建立了铀尾矿氡析出的数学模型和蒙特卡罗模拟方法，模拟了不同含水饱和度条件下铀尾矿颗粒粒度对氡析出的影响。结果表明，镭分布于颗粒表面时，4种含水饱和度（5％、20％、50％、75％）条件下的 K均随颗粒尺寸的增大先增大后趋于稳定。镭分布在距颗粒表面34 nm和68 nm时，含水饱和度为5％或20％的条件下，K先增加后趋于稳定，而含水饱和度为50％或75％的条件下， K随颗粒尺寸的增大先稍有下降然后逐渐稳定。运用蒙特卡罗方法计算了各铀尾矿样品的氡析出率，计算的氡析出率与实测铀尾矿氡析出率符合较好，相对误差为3％～9％。

英文摘要：

A mathematical model and Monte-Carlo simulation method of radon exhala-tion from uranium tailings were developed based on the nuclear recoil theory .The grain size effect on radon exhalation under different moisture contents was simulated .When radium is distributed on grain surface , K increases with grain size and then remains a constant value under moisture contents of 5% ,20% ,50% and 75% .When radium is distributed to a depth of 34 nm or 68 nm from the surface ,K firstly increases with grain size and then reaches a constant value under moisture contents of 5% and 20% ,and K decreases with the increase of grain size and then becomes a constant value under mois-ture contents of 50% and 75% .The radon exhalation rate of the uranium tailings sam-ples was calculated by Monte-Carlo method .The calculated radon exhalation rate agrees well with that obtained by experiment ,and the relative error is 3%-9% .