Study On The Detection And Analysis Of Radioactivity And Heavy Metals Around Some Uranium Mines In Inner Mongolia

The mining activities and demand of uranium resources in China are increasing with the development of nuclear power industries and the rising of uranium price internationally.In recent years,there have been explored the many large reserves of uranium in china,especialy in Inner Mongolia such as,in the northern area of Ordos Basin,eastern part of Erenhot Basin Tongliao area of Songliao Basin and Hailaer Basin.The Daying area of Ordos Basin was found to be the largest of reserve of sandstone-type uranium in China,which occupies above the half of sandstone-type uranium reserves of China.The larger mining areas are needed in China because of the low grade uranium.The in situ leaching has been adopted in sandstone-type uranium areas in China since21^th.In recent years,people have been aware of the environmental effects concerning to in situ leaching processes.The investigation of radioactivity and heavy metals in the soil and ground water around the uranium mines have become very important,which is of great significance for the possible environmental impact of the exploitation of uranium deposits,the measurement and evaluation of nuclear accidents and the stable development of society.However,there are few reports about radiation and heavy metal level of environmental media around uranium mines in China,especially concerning to the prospective uranium mines.In this paper,the radionuclides and heavy metals in soil around the Tongliao uranium mine,Bayanwala uranium mine and Nalingou uranium mine in Inner Mongolia were investigated and radioactive levels in drinking water around the mines were determined.Furthermore,the radiation dose to residents was assessed.The determination and assessment were conducted before the mining activities of Bayanwala uranium mine and Nalingou uranium mine.Natural and artificial radionuclides and heavy metals in the surface soil around uranium mines Inner Mongolia were measured using gamma spectrometry,flame atomic absorption spectrometry,graphite furnace atomic absorption spectrometry,microwave dissolution atomic fluorescence spectrometry and inductively coupled plasma-mass spectrometry.The gross alpha and gross beta activities in drinking water were determined using the low level gross alpha and beta meter.The health risk assessment from radionuclides and heavy metals in soil and drinking water were assessed.Indoor and outdoor ambient dose rates around the mines were measured.The methods recommended by World Health Organization and Chinese Standards were used in analyses and determination of radionuclides and heavy metals.Each sampling location was determined by global positioning system?GPS?and the sampling positions were presented using software SRI Arc GIS desktop 10.1.The quality control has been taken to measuring devices using GEANT4 and ROOT to ensure the reliability and accuracy of data.The major works and research results are summarized into the following sections:The concentrations of radionuclides(²³⁸U,²³²Th,²²⁶Ra,⁴⁰K and ¹³⁷Cs)and heavy metals?Pb,Cd,Cu,Zn,Hg and non-metal As?in the surface soil around the Tongliao uranium mining area determined and those values are all within the Chinese background levels.The radiation and heavy metal hazard indices for residents are within the acceptable ranges.The concentrations of gross alpha and gross beta in drinking water samples were below the screening levels recommended by World Health Organization and Chinese Standard.It was presented that the concentrations of radionuclides and heavy metals in the surface soil around the Bayanwula uranium mine are among the Chinese background levels.The health risk impacts for the residents from radionuclides and heavy metals in the surface soil are at very low level.The indoor and outdoor gamma ambient dose rates indicate that air gamma dose rate in red-brisk houses is higher than that in Mongolian Gers.It was found that the mean concentrations of gross alpha in drinking water samples around Bayanwula uranium mining area also exceed the screening level recommended by World Health Organization.Furthermore,the radionuclides in drinking water samples were determined and the results showed that cancer risk for residents was at very low level.The concentrations of radionuclides and heavy metals in the surface soil around the Nalingou uranium mine are among the background values of China.The concentrations of gross alpha and gross beta in drinking water around Nalingou uranium mine do not exceed the screening values recommended by World Health Organization.The health risk from the radionuclides and heavy metals in surface soil around Nalingou uranium mine is at low level.The transfer of uranium in the soil-forage?drinking water?-goat?sheep?ecosystem in the surrounding environment of Bayanurla uranium mine was studied.The distribution of uranium in the stomach,liver,heart,kidney and blood of goat?sheep?and their transfer coefficients were determined.The characteristic and the model of the radionuclide transfer in the surrounding media of Bayanwula uranium mine were determined.