Radioactivity of Natural Nuclides (40K, 238U, 232Th, 226Ra) in Coals from Eastern Yunnan, China

Minerals

Xin Wang²  Qiyan Feng²  Ruoyu Sun³  Guijian Liu²  Shifeng Dai¹ 

[1] School of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221000, ChinaSchool of Environment Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221000, China;Chinese Academy of Sciences Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China;

关键词: coal;    radioactivity;    nuclide;    Yunnan;    China;   

DOI  :  10.3390/min5040513

来源: mdpi

【 摘 要 】

The naturally occurring primordial radionuclides in coals might exhibit high radioactivity, and can be exported to the surrounding environment during coal combustion. In this study, nine coal samples were collected from eastern Yunnan coal deposits, China, aiming at characterizing the overall radioactivity of some typical nuclides (i.e., ⁴⁰K, ²³⁸U, ²³²Th, ²²⁶Ra) and assessing their ecological impact. The mean activity concentrations of ²³⁸U, ²³²Th, ⁴⁰K and ²²⁶Ra are 63.86 (17.70–92.30 Bq·kg⁻¹), 23.76 (11.10–37.10 Bq·kg⁻¹), 96.84 (30.60–229.30 Bq·kg⁻¹) and 28.09 Bq·kg⁻¹ (3.10–61.80 Bq·kg⁻¹), respectively. Both ²³⁸U and ²³²Th have high correlations with ash yield of coals, suggesting their inorganic origins. The overall environmental effect of natural radionuclides in studied coals is considered to be negligible, as assessed by related indexes (i.e., radium equivalent activity, air-adsorbed dose rate, annual effective dose, and external hazard index). However, the absorbed dose rates values are higher than the average value of global primordial radiation and the Chinese natural gamma radiation dose rate.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.