Department of Mining Engineering, Indian School of Mines, Dhanbad - 826 004, Jharkhand, India.
J Environ Radioact. 2013 Dec;126:104-14. doi: 10.1016/j.jenvrad.2013.07.014. Epub 2013 Aug 23.
Estimation of radon emanation in uranium mines is given top priority to minimize the risk of inhalation exposure due to short-lived radon progeny. This paper describes the radon emanation studies conducted in the laboratory as well as inside an operating underground uranium mine at Jaduguda, India. Some of the important parameters, such as grade/(226)Ra activity, moisture content, bulk density, porosity and emanation fraction of ore, governing the migration of radon through the ore were determined. Emanation from the ore samples in terms of emanation rate and emanation fraction was measured in the laboratory under airtight condition in glass jar. The in situ radon emanation rate inside the mine was measured from drill holes made in the ore body. The in situ(222)Rn emanation rate from the mine walls varied in the range of 0.22-51.84 × 10(-3) Bq m(-2) s(-1) with the geometric mean of 8.68 × 10(-3) Bq m(-2) s(-1). A significant positive linear correlation (r = 0.99, p < 0.001) between in situ(222)Rn emanation rate and the ore grade was observed. The emanation fraction of the ore samples, which varied in the range of 0.004-0.089 with mean value of 0.025 ± 0.02, showed poor correlation with ore grade and porosity. Empirical relationships between radon emanation rate and the ore grade/(226)Ra were also established for quick prediction of radon emanation rate from the ore body.
铀矿中氡的逸出率估算被置于首要地位，以最大程度地降低因短寿命氡子体吸入而导致的辐射风险。本文描述了在实验室以及印度贾杜达地下铀矿中进行的氡逸出研究。测定了一些重要的参数，例如品位/（226）Ra 活度、水分含量、体密度、孔隙率和矿石的逸出分数，这些参数控制着氡通过矿石的迁移。在密封的玻璃罐中，在实验室条件下，以逸出率和逸出分数的形式，测量了矿石样品的逸出。通过在矿体中钻出的钻孔，测量了矿内的原位氡逸出率。矿壁内的原位（222）Rn 逸出率范围在 0.22-51.84×10(-3) Bq m(-2) s(-1)，几何平均值为 8.68×10(-3) Bq m(-2) s(-1)。原位（222）Rn 逸出率与矿石品位之间存在显著的正线性相关（r = 0.99，p < 0.001）。矿石样品的逸出分数在 0.004-0.089 之间变化，平均值为 0.025 ± 0.02，与矿石品位和孔隙率相关性较差。还建立了氡逸出率与矿石品位/（226）Ra 之间的经验关系，以便快速预测矿体的氡逸出率。
