离子型稀土矿辐射水平及其所致工作人员剂量

目的 通过调查广东省、江西省4座离子型稀土矿辐射水平，进行工作人员剂量评价，为保护工作人员健康和制定监督管理策略提供科学依据。方法 采用Rn-Tn累积探测器、RAD7连续测氡仪、BWLM-PLUS氡子体测量仪、X（γ）辐射剂量当量率仪和γ谱仪，对稀土矿进行了²²²Rn/²²⁰Rn及其子体、γ辐射水平和土壤（原矿）中放射性核素含量的监测与分析。结果 稀土矿山顶的工人值班室²²⁰Rn浓度范围388～871 Bq/m³，灼烧车间γ剂量率560 nGy/h。除土壤中放射性核素²²⁶Ra、²³²Th含量偏低于环境对照点外，其他工作场所辐射水平均略偏高于环境对照点。结论 工作人员所受年附加有效剂量在0.15～8.06 mSv/a之间，低于工作人员年有效剂量限值。

Investigation on radiation levels of ion-absorbed rare earth mines and dose assessment to workers

Objective To provide scientific basis for protecting workers' health and formulating supervision and management strategies though investigation in radiation levels of 4 ion-absorbed rare earth mines in Guangdong Province and Jiangxi Province, and assessment of the dose to workers.Methods The concentration of ²²²Rn/²²⁰Rn and its progeny, γ radiation level and radionuclide content in soil (raw ore) were monitored in rare earth mines by using Rn-Tn nuclear track detectors, RAD7 continuous radon monitors, BWLM-PLUS radon daughter working-level monitor, X(γ) radiation dose equivalent rate meter and γ spectrometer.Results The concentration range of ²²⁰Rn in the duty room on the top of the rare earth mine was 388～871 Bq/m³, and the γ radiation level of the product in the burning workshop was 560 nGy/h. Except the contents of ²²⁶Ra and ²³²Th in the soil(raw ore) were lower than that in the environmental control points, the radiation levels in other workplaces were higher than that in the control points.Conclusion The additional annual effective dose was below the annul effective dose limit, which was in the range of 0.15～8.06 mSv/a.