江西省伴生放射性石煤矿开发利用环境影响研究

STUDY ON ENVIRONMENTAL EFFECT OF MINING AND UTILIZING RADIOACTIVE BONE-COAL MINE IN JIANGXI PROVINCE

本文报道了江西省石煤开发利用过程中 ,石煤矿区室内 (碳化砖房 )、外γ辐射水平和年均氡浓度 ,石煤、石煤渣、碳化砖、矿区土壤、石煤矿坑道排放水中天然放射性核素和重要非放元素的调查方法和主要结果。并计算了石煤矿区 (居住碳化砖房 )居民的附加剂量。结果表明 :1 )石煤矿区室内 (碳化砖房 )、外γ辐射剂量率按调查的三县平均 (下同 )分别为 2 68nGy/h和 2 78nGy/h ;2 )碳化砖建筑物室内年平均氡浓度 85 .7Bq/m3;3 )石煤中2 38U和2 2 6 Ra的含量均约为 1 .5kBq/kg,石煤渣、碳化砖中均约为 0 .9kBq/kg ,矿区土壤中分别约为 0 .5kBq/kg和 0 .4kBq/kg ,分别是当地土壤背景值的 8.1倍和 6.4倍 ;4)石煤中也伴生许多有毒有害的非放物质 ,石煤、石煤渣、碳化砖、矿区土壤中的Cu、Cd、Cr、Zn、As含量高于当地背景值 ,剧毒元素Cd、As污染严重 ,矿区土壤中Cd和As分别超过国家土壤环境质量标准 (三级 )的3 .1倍和 1 .4倍 ;5 )石煤矿坑道排放废水中U、Th、2 2 6 Ra、4 0 K的含量分别为 1 7.5 μg/L、7.0 μg/L、1 41mBq/L、3 3 3mBq/L ;6)石煤矿区 (居住碳化砖房 )的居民因γ辐射外照射和吸入氡子体所致附加年有效剂量分别为 0 .87mSv和 1 .0mSv ,合计 1 .9mSv ;7)有相当一部分石煤渣不能以质量分数大于 2 0 %?

This paper introduces the method for investigating the γ-radiation level and annual average concentration of Rn inside and outside the houses built by the bone-coal cinder brick, and natural radionuclide level in bone-coal, bone-coal cinder, bone-coal cinder brick, soil in mining area and water discharging from the tunnel of bone-coal mine in the process of mining and utilizing bone-coal in Jiangxi province. Main results are reported, and additional doses to inhabitants living in bone-coal cinder brick houses in mining area are also calculated. The results show that:1) γ radiation dose rates inside and outside the houses built by the bone-coal cinder brick in bone-coal mining area are 268 nGy/h and 278 nGy/h, respectively;2) Annual average concentration of Rn in buildings constructed by the bone-coal cinder brick is 85.7 Bq/m 3;3) The contents of 238U and 226Ra are both 1.5 kBq/kg in bone-coal, about 0.9 kBq/kg in bone-coal cinder and bone-coal cinder brick, and about 0.5 kBq/kg and 0.4 kBq/kg in soil in mining area, which are respectively 8.1 times and 6 4 times that in soil in Jiangxi province; 4) There are many associated toxic non-radioactive elements in bone-coal. The concentrations of Cu, Cd, Cr, Zn, As and F in bone-coal, bone-coal cinder, bone-coal cinder brick, soil in mining area are higher than local background values. Pollution of Cd and As is serious and the concentrations of Cd and As are 3.1 times and 1.4 times that of National Soil Environment Quality Standards (Level III);5) The levels of U, Th, 226Ra, 40K in waste water discharging from the tunnel of bone-coal mine are 17.5 μg/L, 7.0 μg/L, 141 mBq/L and 333 mBq/L, respectively.6) For inhabitants living in bone-coal cinder brick houses in mining area, annual average additional effective doses resulted from γ radiation and inhalation of 222Rn are 0.87 mSv and 1.0 mSv respectively, totally 1.9 mSv.7)Most of bone-coal cinder might not be used in building material when its massic fraction is more than 20%. (