广东下庄铀矿田土壤天然放射性测定及环境影响评价

Determination of natural radioactivity of soil and assessment of radioactive environmental impact in Xiazhuang granite uranium ore field, Guangdong

用高纯锗γ能谱分析仪测量了广东下庄铀矿田土壤中放射性核素226Ra、232Th和40K的比活度,它们分别为112(40.2—442)Bq/kg,71.5(32.6—88.1)Bq/kg,672(442—913)Bq/kg。同全国和全世界的平均值相比,226Ra的含量明显偏高。在测得放射性核素226Ra、232Th和40K的比活度此基础上,计算了距地面1m高处空气中γ辐射吸收剂量率和年有效剂量率,并对γ辐射外照射水平进行了评价。评价结果表明,下庄铀矿田的土壤中天然放射性水平处于正常范围。

This work deals with the determination of natural radioactivity of soil in Guangdong Province Xiazhuang granite uranium ore field by using a γ-my spectrometer. The activity concentrations for ^226Ra, ^232Th and ^40K obtained were 112 （from 40.2 to 442）, 71.5 （from 32.6 to 88.1）, and 672 （from 442 to 913） Bq/kg, respectively. Compared with the average value of countrywide and worldwide, the activity concentration of ^226Ra was obviously greater than them. To assess the radiological hazard of the natural radioactivity in soil, the absorbed dose rate and annual effective dose rate were calculated. The results show that there is a normal level of natural radioactivity of soil in the Xiazhuang granite uranium ore field.