Rood A S, White G J, Kendrick D T
Idaho National Engineering and Environmental Laboratory, Idaho Falls 83415, USA.
Health Phys. 1998 Aug;75(2):187-92. doi: 10.1097/00004032-199808000-00011.
222Rn flux (Bq s(-1)) was measured from the ends of twenty sections of produced water injection tubing (pipe) containing barite scale contaminated with naturally occurring radioactive material. Exposure measurements near the pipes were as high as 77.4 nC kg(-1)h(-1) (300 microR h(-1)). Flux measurements were accomplished by first purging the pipes with dry nitrogen and then collecting the outflow (nitrogen and radon) on charcoal columns affixed to the end of the pipe for 66 hours. As determined in this manner, 222Rn flux from the ends of the pipe ranged from 0.017 to 0.10 Bq s(-1) (0.46 to 2.7 pCi s(-1)). Following the radon flux measurements, pipe scale was removed and a representative sample was taken for 226Ra and 228Ra concentration measurements and determination of 222Rn emanation fractions (the fraction of the total radon contained in a material that is released from the material and free to migrate). The samples were also analyzed for gross mineral content. Emanation fraction measurements for 222Rn ranged from 0.020 to 0.063, while 226Ra concentrations ranged from 15.7 to 102 Bq g(-1) (424 to 2,760 pCi g(-1)). Barite was the predominate mineral in 17 of the 20 scale samples collected. Much of the previous work dealing with radon emanation fraction measurements has involved uranium mill tailings. Compared to mill tailings and natural soils which have emanation fractions that typically range from 0.1 to 0.3, the emanation fractions measured for these NORM scales are substantially lower.
对20段含有被天然放射性物质污染的重晶石垢的采出水注入油管（管道）末端的222Rn通量（贝克勒尔每秒，Bq s(-1)）进行了测量。管道附近的暴露测量值高达77.4纳库仑每千克每小时（nC kg(-1)h(-1)）（300微伦琴每小时，microR h(-1)）。通量测量的方法是，首先用干燥氮气吹扫管道，然后将流出物（氮气和氡）收集在固定于管道末端的活性炭柱上66小时。通过这种方式测定，管道末端的222Rn通量范围为0.017至0.10贝克勒尔每秒（Bq s(-1)）（0.46至2.7皮居里每秒，pCi s(-1)）。在进行氡通量测量之后，去除管道垢，并采集代表性样品进行226Ra和228Ra浓度测量以及222Rn析出率（材料中所含总氡中从材料中释放并可自由迁移的部分）的测定。还对样品的总矿物质含量进行了分析。222Rn的析出率测量值范围为0.020至0.063，而226Ra浓度范围为15.7至102贝克勒尔每克（Bq g(-1)）（424至2760皮居里每克，pCi g(-1)）。在所采集的20个垢样中，有17个的主要矿物为重晶石。之前许多关于氡析出率测量的工作都涉及铀矿尾矿。与析出率通常在0.1至其0.3范围内的尾矿和天然土壤相比，这些天然放射性物质垢的析出率要低得多。
