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1.
对长约70 km引水工程洞线上进行的地面伽马能谱测量、陆地伽马剂量率测量、土壤氡浓度测量、岩石表面氡析出率测量以及钻孔岩芯样品的放射性元素U、Ra、Th、K含量分析的综合放射性地质调查,并对获得的测量数据进行分析研究。结果表明,测区引水沿线地质体放射性核素当量含量平均值为：U 1.56×10-6,Th 14.12×10-6,K 2.16×10-2;钻孔岩芯放射性元素分析含量平均值为：U 32.34 Bq/kg,Ra 35.68 Bq/kg,Th 35.29 Bq/kg,K 865.65 Bq/kg。陆地伽马剂量率为90.42 nGy/h;土壤氡浓度平均值为4 272.1 Bq/m3;岩石表面析出率平均值为4.01×10-2 Bq/m2·s。根据测量结果,利用内照射和外照射辐射剂量计算了对施工人员造成的辐照剂量为0.759 mSv,低于国家对公众的剂量限值1 mSv/a,表明引水工程输水隧洞的施工在安全辐射范围内。 相似文献
2.
《地下水》2021,(3)
为取得二连盆地脑木根凹陷铀成矿水文地质条件,运用地下水动力学、水文地球化学、铀水文地球化学等知识,通过调查取样,分析数据,整理资料等进行研究。结果表明:该地区地下水水动力特征为从北西部、南东部的补给区向中部的排泄区径流;地下水水化学类型以Cl·HCO_3-Na、Cl-Na型水为主,矿化度最高106.50 g/L,平均3.50 g/L;该地区地下水水中铀含量较高,平均值为120μg/L,最高值可达910μg/L,自然底数为56.00μg/L,水中氡浓度平均值为100 Bq/L,最高值可达14 985 Bq/L,自然底数为95 Bq/L。研究结果表明该地区地下水环境特征有以利于铀成矿、富集。 相似文献
3.
利用ARD型γ能谱仪对辽宁省大连市区地表天然放射性核素238U、232Th、40K含量进行了现场测量.调查结果显示,大连市区238U、232Th、40K比活度平均值分别为23.09 Bq/kg（范围值1.24~151.91 Bq/kg）、18.99 Bq/kg（范围值0.41~92.57 Bq/kg）、386.39 Bq/kg（范围值31.30~1095.50 Bq/kg）,均显著低于全国和世界的平均值.在测得的238U、232Th、40K含量基础上,计算了距地面1 m高处空气中γ辐射吸收剂量率、外照射指数、内照射指数和年有效剂量等参数,并据此对大连市区天然放射性水平进行了评价.空气中γ辐射吸收剂量率（Dr）平均值为39.04 nGy/h,远低于全国（81.5 nGy/h）和世界（80 nGy/h）平均水平.外照射指数、内照射指数平均值分别为0.23、0.12,均远小于国家对建筑材料外照射指数的限值1.年有效剂量为0.048 mSv,远低于世界年平均有效剂量（0.46 mSv）以及公众外照射年有效剂量（1.0 mSv）的限值.评价结果表明,大连市区地表天然放射性辐射处于安全的水平. 相似文献
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5.
地面伽马能谱测量是铀矿勘查中最常用的方法,可直接测得地表铀、钍、钾等放射性元素含量。鹿井铀矿田是20世纪发现的大型铀矿富集区。鹿井西部铀矿勘查工作程度较低,为了探索鹿井铀矿田西部的资源前景,在该地区开展了地面伽马能谱测量。通过钍铀比、古铀量能谱特征参数,以及计算传统统计法、含量-面积法计算异常下限对能谱数据进行综合处理。结合地质背景,分析了研究区放射性元素含量及分布特征,总结了铀成矿与地质因素的关系,并圈定了放射性异常位置。研究结果表明,铀在后期发生了二次迁移富集,其成因是富铀热液的迁移与断裂构造和地层岩性接触面发生的蚀变作用,该地区主要控矿因素是断裂构造及其次级裂隙和地层的岩性接触面。经过能谱特征参数及铀、钍异常下限分析,预测了三片铀成矿有利区,为研究区下一步找矿工作提供了依据。 相似文献
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7.
上扬子地区是我国页岩气重要开采区,也是氦气工业性开采的唯一地区,但对于其氦气生成潜力研究仍处于空白阶段.据此,对上扬子东南地区采集的144件岩石样品进行场发射扫描电镜及铀、钍强度测试,理论计算了页岩气中氦气达到我国工业开采标准(0.05％)需要满足的理论条件.岩石扫描电镜结果表明,富含铀、钍的副矿物(锆石、独居石、铀钍石及磷灰石等)主要赋存于造岩矿物石英和长石中.岩石铀、钍强度测试结果表明,三大类岩石中铀平均含量呈现:沉积岩(8.96×10-6)＞岩浆岩(4.83×10-6)＞变质岩(1.89×10-6);钍平均含量呈现:沉积岩(11.01×10-6)≈变质岩(10.4×10-6)＞岩浆岩(5.9×10-6).岩浆岩中铀、钍平均含量呈现:酸性岩＞中性岩＞基性岩＞超基性岩;沉积岩中铀平均含量呈现泥页岩(13.86×10-6)＞＞砂岩(2.54×10-6)＞碳酸盐岩(1.67×10-6);钍平均含量呈现泥页岩(12.50×10-6)≈砂岩(12.76×10-6)＞碳酸盐岩(5.96×10-6).不同沉积时代沉积岩中铀、钍平均含量也呈现上述分布规律.沉积岩中铀、钍含量主要与岩石的沉积环境与物源有关,与沉积时代无关.单位时间、单位质量岩石氦气生成量的大小为:泥页岩＞酸性岩＞中性岩＞砂岩＞变质岩＞碳酸盐岩＞基性岩＞超基性岩.以中国南方地区上奥陶统五峰组—下志留统龙马溪组页岩为例,当该层位泥页岩中残余氦气含量为U,Th元素衰变释放出来氦气含量的80％以上时,适合进行"页岩气+氦气"的共同开采,提高页岩气的开采价值. 相似文献
8.
上扬子地区是我国页岩气重要开采区,也是氦气工业性开采的唯一地区,但对于其氦气生成潜力研究仍处于空白阶段.据此,对上扬子东南地区采集的144件岩石样品进行场发射扫描电镜及铀、钍强度测试,理论计算了页岩气中氦气达到我国工业开采标准(0.05％)需要满足的理论条件.岩石扫描电镜结果表明,富含铀、钍的副矿物(锆石、独居石、铀钍石及磷灰石等)主要赋存于造岩矿物石英和长石中.岩石铀、钍强度测试结果表明,三大类岩石中铀平均含量呈现:沉积岩(8.96×10-6)＞岩浆岩(4.83×10-6)＞变质岩(1.89×10-6);钍平均含量呈现:沉积岩(11.01×10-6)≈变质岩(10.4×10-6)＞岩浆岩(5.9×10-6).岩浆岩中铀、钍平均含量呈现:酸性岩＞中性岩＞基性岩＞超基性岩;沉积岩中铀平均含量呈现泥页岩(13.86×10-6)＞＞砂岩(2.54×10-6)＞碳酸盐岩(1.67×10-6);钍平均含量呈现泥页岩(12.50×10-6)≈砂岩(12.76×10-6)＞碳酸盐岩(5.96×10-6).不同沉积时代沉积岩中铀、钍平均含量也呈现上述分布规律.沉积岩中铀、钍含量主要与岩石的沉积环境与物源有关,与沉积时代无关.单位时间、单位质量岩石氦气生成量的大小为:泥页岩＞酸性岩＞中性岩＞砂岩＞变质岩＞碳酸盐岩＞基性岩＞超基性岩.以中国南方地区上奥陶统五峰组—下志留统龙马溪组页岩为例,当该层位泥页岩中残余氦气含量为U,Th元素衰变释放出来氦气含量的80％以上时,适合进行"页岩气+氦气"的共同开采,提高页岩气的开采价值. 相似文献
9.
上扬子地区是我国页岩气重要开采区,也是氦气工业性开采的唯一地区,但对于其氦气生成潜力研究仍处于空白阶段.据此,对上扬子东南地区采集的144件岩石样品进行场发射扫描电镜及铀、钍强度测试,理论计算了页岩气中氦气达到我国工业开采标准(0.05％)需要满足的理论条件.岩石扫描电镜结果表明,富含铀、钍的副矿物(锆石、独居石、铀钍石及磷灰石等)主要赋存于造岩矿物石英和长石中.岩石铀、钍强度测试结果表明,三大类岩石中铀平均含量呈现:沉积岩(8.96×10-6)＞岩浆岩(4.83×10-6)＞变质岩(1.89×10-6);钍平均含量呈现:沉积岩(11.01×10-6)≈变质岩(10.4×10-6)＞岩浆岩(5.9×10-6).岩浆岩中铀、钍平均含量呈现:酸性岩＞中性岩＞基性岩＞超基性岩;沉积岩中铀平均含量呈现泥页岩(13.86×10-6)＞＞砂岩(2.54×10-6)＞碳酸盐岩(1.67×10-6);钍平均含量呈现泥页岩(12.50×10-6)≈砂岩(12.76×10-6)＞碳酸盐岩(5.96×10-6).不同沉积时代沉积岩中铀、钍平均含量也呈现上述分布规律.沉积岩中铀、钍含量主要与岩石的沉积环境与物源有关,与沉积时代无关.单位时间、单位质量岩石氦气生成量的大小为:泥页岩＞酸性岩＞中性岩＞砂岩＞变质岩＞碳酸盐岩＞基性岩＞超基性岩.以中国南方地区上奥陶统五峰组—下志留统龙马溪组页岩为例,当该层位泥页岩中残余氦气含量为U,Th元素衰变释放出来氦气含量的80％以上时,适合进行"页岩气+氦气"的共同开采,提高页岩气的开采价值. 相似文献
10.
为查明二连盆地苏尼特右旗地区HFU-39、HFU-40航放异常的铀成矿情况,本文在分析异常区区域地质资料基础上,采用地质剖面测量、地面伽玛总量测量、伽玛能谱剖面测量、土壤氡剖面测量及岩石化探取样分析综合方法,对HFU-39、HFU-40两个异常进行查证及评价。查证结果显示异常呈团块状展布,地面伽玛能谱测量铀含量最高达w（U）=135×10-6,岩石化学分析铀含量最高达w（U）=256×10-6,该区域氡异常突出;综合异常查证结果和对二连盆地泥岩型铀矿化的形成环境分析,指出了该区的下一步铀找矿方向。 相似文献
11.
伽马能谱测量在陆地伽马空气吸收剂量率评价中的应用 总被引：2，自引：2，他引：2
2002～200年,国内首次采用就地伽马能谱测量方法在广东珠海市进行了面积性测量,并用该方法定量解释求得的钾、铀、钍含量用Beck公式估算了地表1 m高处的吸收剂量率,同时用塑料闪烁体X-γ吸收剂量率仪在相同测点做了比对测量.2种方法对比结果(514个测点)显示很好的一致性,珠海市区实测吸收剂量率和伽马能谱估算吸收剂量率平均值分别为(145.07±26.5) nGy/h和(162.10±1.51) nGy/h,计算结果与实测结果的相对误差为11.74%. 相似文献
12.
氡气灾害是一种广泛分布的地质灾害。室内氡气浓度偏高会使居民患肺癌的几率增高，而室内氡气主要来自房屋地基所在的地质单元。笔者在美国犹他大学研究所工作期是，研究了瑞丁普朗花岗片麻岩带近地表氡的浓度与铀含量的关系以及铀的分布与居民癌症死亡率之间的相关关系。铀的区域性分布是利用航空伽马能谱测量资料求得的，说明利用航空伽马能谱测量资料开展氡气灾害区域评价的可能性。文中还举例说明氡气调查在制定建设规划方面的作 相似文献
13.
华阳川铀铌铅矿床是北秦岭造山带内一种类型特殊的铀多金属矿床。为了实现在外围快速找矿的目的,在矿床及其周边开展了1∶1万高精度航空磁放测量,获得高精度的航空放射性数据,通过对航放数据的解释,对下一步找矿勘探工作的部署有重要意义。通过对宏观上放射性元素的分布特征的研究,认为铀、钾异常分布特征相似,在测区西部有大面积分布,东部无成规模异常,钍异常在测区中部形成东西向异常带,与韧性剪切带的位置一致。铀异常有明显受北西向和北东向两组断裂控制,且在华阳川断裂北东盘异常面积大,强度高,但南西盘太古宙地层却无明显铀异常。本次研究计算了钍钾比、钍铀比、铀钾比、古铀含量、活性铀含量等参数,掌握了元素在不同地层单元的迁移富集规律。根据航空放射性异常,开展地面验证工作,圈定3条铀矿化带,达到了快速找矿的目的,对铀矿等战略性矿产的成矿规律研究及找矿勘查有积极意义。 相似文献
14.
P. Ravikumar R. K. Somashekar 《International Journal of Environmental Science and Technology》2014,11(2):493-508
The distribution of radon in ground and surface water samples in Sankey Tank and Mallathahalli Lake areas was determined using Durridge RAD-7 analyzer with RAD H2O accessory. The radiation dose received by an individual falling under different age groups (viz., 3 months; 1, 5, 10, 15 years and adult) depending upon their average annual water consumption rate was attempted. The mean radon activity in surface water of Sankey Tank and Mallathahalli Lake was 7.24 ± 1.48 and 11.43 ± 1.11 Bq/L, respectively. The average radon activities ranged from 11.6 ± 1.7 to 381.2 ± 2.0 Bq/L and 1.50 ± 0.83 to 18.9 ± 1.59 Bq/L, respectively, in 12 groundwater samples each around Sankey Tank and Mallathahalli Lake areas. Majority of the measured groundwater samples (viz., 100 % in Sankey Tank area and 75 % in Mallathahalli Lake area) showed mean radon values above the EPA’s maximum contaminant level of 11.1 Bq/L and only 66.67 % of samples in Sankey Tank area showed radon above the WHO and EU’s reference level of 100 Bq/L. The overall radiation dose due to radon emanating from water in the study area was increasing with increase in age and water consumption rates, but significantly lower than UNSCEAR and WHO recommended limit of 1 mSv/year except for few groundwater samples in Sankey Tank area (i.e., 0.92, 0.99 and 1.39 mSv/year). The radiation dose rate received by bronchial epithelium via inhalation was very high compared to that by stomach walls via ingestion. 相似文献
15.
K. S. Banerjee R. Guin J. L. Gutierrez-Villanueva M. E. Charro D. Sengupta 《Environmental Earth Sciences》2012,65(7):2103-2110
The determination of the natural radioactivity has been carried out, by means of gamma-ray spectrometry, in exposed rock samples
collected from various geological formations across the Singhbhum Shear Zone of India. The spatial variation in the concentration
of primordial radionuclides reflects, in general, the geochemical variance among the analyzed rocks and affirms the earlier
views on genesis of uranium mineralization. This study further speculates new possibilities of thorium depletion during shearing
and metamorphism. All the obtained U-values were more than the worldwide average U-concentration (which is about 40 Bq/kg).
Interestingly, U-concentration in mica schists from Singhbhum group of rocks and in slates and argillaceous quartzites from
Iron Ore group of rocks was five to seven times higher than the global values. In contrast, the granites in study area showed
comparatively lower U-concentration. The overall results suggest the control of complex metamorphism and shearing on U-distribution
in the terrane. The contribution of 238U, 232Th and 40K to the total radiation dose in the study area was found to be significant ranging from 110 to 310 nGy/h in comparison with
the lower global, as well as Indian average values. 相似文献
16.
Spatio-temporal variation in radon concentration in groundwater with respect to rock types: A case study from Chitradurga district,Karnataka 总被引：1，自引：0，他引：1
P. Ravikumar Deljo Davis Sharika Mathew R. K. Somashekar K. L. Prakash 《Journal of the Geological Society of India》2014,83(2):156-164
An attempt was made in the present study to delineate how the radon concentrations vary with respect to different geological formations and to evaluate annual effective dose exposure due to ingestion of radon. A total of 60 groundwater samples were collected from layered sequential aquifers in Chitradurga district having major rock types such as Bababudan Group, Charnockite, Chitradurga Group, Closepet granite, migmatites and granodiorite — tonalitic gneisses and Sargur Schist complex during pre-monsoon and post-season of the year 2011. Radon measurement was made using Durridge RAD-7 radon-in-air monitor, connected to RAD H2O accessory with closed loop aeration concept. In the present study, the radon activity ranged from 0 to 186.6 Bq/L and 0 to 150.6 Bq/L during pre- and post-monsoon seasons of the year 2011, with 56.67 % (17 samples) of samples during both the seasons exceeding the EPA’s MCL value of 11.1 Bq/L. The annual mean radon activity in the groundwater was higher in the area having Chitradurga rock group formations (78.1 Bq/L) followed by Sargur-Satyamangalam schist complex group (56.8 bq/L), migmatites and granodiorite — tonalitic Gneisses group (56.3 Bq/L), Closepet granite (42.7 Bq/L), Charnonkite (29.1 Bq/L) and Bababudan Group (22.2 Bq/L). It is inferred that radon concentration found to depend on the tectonic structure, geology of the area and on the presence of uranium minerals in these rocks. The annual effective dose resulting from radon in groundwater in the Chitradurga district were significantly lower than UNSCEAR and WHO recommended limit of 1 mSv/y. 相似文献
17.
介绍了伽马射性脉冲计数和米测温的工作原理，总结了已知温泉附近伽马射性脉冲计数和米测温特点：张性断层上方具有较高的伽马射线脉冲计数；在脉冲计数最大测点做伽马能谱测量得出该地铀元素含量较高；米温结果显示该地具有较高的热背景值。依据上述特征，在同一断层的另一泉水出露地区，开展了伽马射线脉冲计数和米测温工作，但伽马射线脉冲计数较小，米测温没有发现有利的地热背景值。泉水化学分析表明，未知区泉水来自浅地表水。地表露头也显示该处断裂后期改造强烈，且形成长达300m的压性断裂带，不宜形成储热构造。 相似文献
18.
Relatively high activity concentrations of some radionuclides (226Ra, 238U, 232Th, and 40K) have been measured in surface and subsurface soils in areas (southern Iraq) where many warfare actions have taken place during the Iran–Iraq and Gulf wars. Such high activity concentrations might be related to the increase in cancerous injuries and birth defects recently reported. The study was aimed to estimate the activity concentrations of some nuclides and a comparison of results with international health hazard indices. In addition, the excess lifetime cancer risk (ELCR) was assessed. Soil samples were collected at three depths (0, 30, and 60 cm) in three locations in Abu Al Khasib and Ad Dayr in Basrah governorates. The average activity concentrations were estimated employing hyper-pure germanium HPGe gamma-ray detection technology. The values obtained in Abu Al Khasib were: 58.44 Bq/kg (226Ra), 43.56 Bq/kg (238U), 19.38 Bq/kg (232Th), and 321.76 Bq/kg (40K) whereas in Ad Dayr 45.71 Bq/kg (226Ra), 35.53 Bq/kg (238U), 20.33 Bq/kg (232Th), and 337.02 Bq/kg (40K). According to UNSCEAR (Sources and effects of ionizing radiations: a report on the effects of atomic radiation to the general assembly with scientific annexes, Annex B, United Nations, New York, 2000) report, higher levels of 226Ra, 238U concentrations than the world’s average values (35 Bq/kg) were observed in both locations. In addition, some radiation hazard indices were determined for both locations: average outdoor external dose (D out), average indoor external dose (D in), total average value of the external dose (D tot), average annual outdoor effective dose (E out), average annual indoor effective dose (E in), and averaged total annual effective dose (E tot). Values for D tot and E tot were higher than the worldwide median (143 nGy/h and 0.48 mSv/y, respectively) in both regions. The measured values of activity concentrations were also used to estimate the outdoor, indoor, and total ELCR. The ELCR values were higher than the worldwide averages. Further analyses and studies need to assess the real risks for human health and possible soil remediation. 相似文献
19.
N. Ayten Uyanık Osman Uyanık Filiz Gür İbrahim Aydın 《Environmental Earth Sciences》2013,68(2):499-506
Some of the rocks and soil-originated materials used in building construction are the serious natural radiation sources. Soil-originated bricks and roof-tiles and their raw material in the Salihli-Turgutlu area were tested in situ for natural radiation levels using a gamma-ray spectrometer. The concentrations of the radioelements 40K, 238U and 232Th and air-absorbed radiation rates were measured for soil, raw material heaps, brick and roof-tile stacks and waste brick heaps. The radium-equivalent activity Raeq of the raw material varied between 187.9 and 216.4 Bq kg?1. The external radiation hazard index Hex values ranged between 0.51 and 0.58. For building material and its products, recommended Raeq and Hex levels are 370 Bq kg-1 and 1.0, respectively. On the other hand, both Raeq and Hex values for waste brick heaps, containing broken brick pieces, coal pieces and ash, were higher than the recommended levels, i.e. Raeq values varied from 473.8 to 651.0 Bq kg-1 and Hex values were within the range 1.15–1.76. The annual dose rate and radium-equivalent activity values of the brick and roof-tiles were below the level of criteria. Annual dose rate ranged between 0.42 and 0.62 mSv y?1 and radium equivalent activity was in the range 172.9–245.2 Bq kg?1. The external and internal radiation hazard indices were all below the value of 1.0 for the Salihli-Turgutlu area bricks and roof-tiles. Results of this study were compared with results of previous studies. Natural radiation levels of construction raw material of study area are generally higher than of those of previous studies. 相似文献