In-situ gamma-ray survey of rare-earth tailings dams – A case study in Baotou and Bayan Obo Districts, China. (January 2016)

• Record Type: Journal Article
• Authors: Li, Baochuan; Wang, Nanping; Wan, Jianhua; Xiong, Shengqing; Liu, Hongtao; Li, Shijun; Zhao, Rong
• Is Part Of: Journal of environmental radioactivity. Volume 151:Part 1(2016:Jan.)
• Page Start: 304
• Page End: 310
• Publication Date: 2016-01
• Subjects: RE tailings dam -- In-situ gamma-ray spectrometry -- Air-absorbed dose rate -- Natural radionuclides -- Bayan Obo; Radioactivity -- Periodicals; Radiation, Background -- Periodicals; Radioecology -- Periodicals; Radioactive pollution -- Periodicals; Environmental Pollutants -- Periodicals; Radioactive Pollutants -- Periodicals; Radioactivity -- Periodicals; Radioécologie -- Périodiques; Pollution radioactive -- Périodiques; Fond de rayonnement -- Périodiques; 539.752
• DOI: 10.1016/j.jenvrad.2015.10.027
• Languages: English
• ISSNs: 0265-931X

Abstract

Abstract: An in-situ gamma-ray spectrometer survey with a scintillation detector of NaI(Tl) (Φ75 mm × 75 mm) was carried out in the Baotou and Bayan Obo Districts in order to estimate the levels of natural radionuclides near rare-earth (RE) tailings dams. In the RE tailings dam of Baotou, the mean concentrations of 238 U and 232 Th were 3.0 ± 1.0 mg/kg (range: 1.9–4.6 mg/kg) and 321 ± 31 mg/kg (range: 294–355 mg/kg), respectively. In the Bayan Obo tailings dam, the mean concentrations of 238 U and 232 Th were 5.7 ± 0.5 mg/kg (range: 5.3–6.1 mg/kg) and 276 ± 0.5 mg/kg (range: 275.5–276.3 mg/kg), respectively. The average 232 Th concentrations in the mining areas of the Bayan Obo Mine and the living areas of the Bayan Obo Town were 18.7 ± 7.5 and 26.2 ± 9.1 mg/kg, respectively. The 232 Th concentration recorded in the tailings dams was much higher than the global average (7.44 mg/kg). Our investigation shows that the 232 Th concentration in the tailings in the Baotou dam was 34.6 times greater than that in the local soil (in Guyang County); the average concentrations of 232 Th in the soil in the Baotou District and Bayan Obo Districts were about 1.35 and 2.82 times greater, respectively, than that in the soil in Guyang County. Based on our results, the highest estimated effective dose due to gamma irradiation was 1.15 mSv per year, estimated from the data observed in the Baotou tailings dams. The results of this preliminary study indicate the potential importance of radioactivity in RE tailings dams and that remedial measures may be required. Highlights: In-situ gamma-ray spectrometry to measure natural radionuclides in rare-earth tailings dam. Comparisons were among the tailings dam, mining area and living areas in Baotou and Bayan Obo. 232 Th concentrations in tailings dams in Baotou and Bayan Obo were much higher than global average. Results provide a baseline useful to assess the radiation influence of the rare-earth tailings dam.