含氡放射性水体氡析出规律的理论研究

Theoretical study on law of radon exhalation in radioactive water containing radon

利用氡扩散运移理论,建立了水体内氡迁移的一维微分方程,推导了水中氡浓度及水体表面氡析出率的计算公式;研究了水底射气介质氡析出率、氡传输速率、水中氡扩散系数以及水体深度等参数对水中氡浓度和水体表面氡析出率的影响。结果表明:在其他参数保持不变时,(1)同一深度处的水中氡浓度和水体表面氡析出率均随水底射气介质氡析出率的增大而增大;(2)同一深度处的水中氡浓度随氡传输速率的增大而减小,而水体表面氡析出率随氡传输速率的增大而增大,且当氡传输速率大于1×10-6m/s时,氡传输速率的变化对水体表面氡析出率的影响不明显;(3)同一深度处的水中氡浓度和水体表面氡析出率均随水中氡扩散系数的增大而增大;(4)水体表面处的水中氡浓度和水体表面氡析出率均随水体深度的增大而减小。

One dimensional differential equation for radon migration in the water containing radon was established using radon seepage-diffusion migration theory and the formula for calculating the concentration of radon in water and the radon exhalation rate at the water surface were derived. In addition, the variation of radon concentration in water and radon exhalation rate at the surface of water were studied when parameter changes such as radon exhalation rate from the emanation medium at the bottom of water body, radon transfer rate, radon diffusion coefficient in water and the depth of the water. The results showed that：when the other parameters remain unchanged, （ 1 ） The concentration of radon at the same depth of water and radon exhalation rate on water surface increases with the increase of radon exhalation rate from the emanation medium at the bottom of water body ; （2） The concentration of radon at the same depth of water decreases and radon exhalation rate on water surface increases with the increase of radon transfer rate ; Furthermore, when radon transfer rate is larger than 1 × 10^ -6m/s, the change of radon exhalation rate on water surface is not obvious with the change of radon transfer rate ; （ 3 ） The concentration of radon at the same depth of water and radon exhalation rate on water surface increases with the increase of radon diffusion coefficient in water; （4）The concentration of radon in water that close to the surface and radon exhalation rate on water surface decreases with the increase of water depth.