新疆伊犁盆地北缘煤炭重点开发区天然放射性水平评价

摘要

The natural radionuclides of the soil in the northern margin of the Yili basin in Xinjiang were measured by the ground gamma spectrometer.The gamma-ray air absorption dose rate and the effective dose were calculated.The results showed that the specific activities of radionuclides 238U,232Th and 40K in the soil were 11.12 ～ 462.26 Bq/kg,8.08 ～100.53 Bq/kg,62.6 ～1 774.71 Bq/kg.The average of the γ-ray air absorption dose rate was 74.18 nGy / h,which was lower than that of the whole country (81.50 nGy / h) and the world (80.00 nGy / h).As the uranium-bearing outcrops were exposed to natural power and human activities under the uranium diffusion,the local radioactive levels were relatively high.However,the uranium-bearing outcrops were limited in size,and their impact on the radioactive environment is small in size and uneven.%利用γ能谱仪对新疆伊犁盆地北缘600 km2面积土壤的天然放射性核素进行了现场测量,计算γ射线空气吸收剂量率和年有效剂量,研究结果显示,该地区土壤中放射性核素238U,232Th和40K比活度分别为11.12 ～462.26 Bq/kg,8.08～100.53 Bq/kg,62.6～ 1774.71 Bq/kg;γ,射线空气吸收剂量率为16.06～ 241.59 nGy/h,均值为74.18 nGy/h,低于全国(81.50 nGy/h)和世界(80.00 nGy/h)的均值;γ外照射年有效剂量在国家标准限量控制的范围内.调查区238U,232Th,40K比活度与局部煤层及其顸板铀矿化出露关系比较密切,但煤层及其顶板(如泥岩)铀矿化厚度和产出规模有限,其对放射性环境的影响具有范围小、不均匀特征.