The Research Of Radon Control Technology Of A Retired Uranium Mine Waste Rock Piles

Accompanied by the development of the nuclear industry and nuclear power, many of the environmental problems caused by decommissioning of nuclear facilities aroused great concern. So far, the total accumulation of uranium waste rock more than400billion tons, as it contains many kinds of natural radionuclides, toxic, long life, and the large amount of waste, serious impact on the local ecological environment and people’s health. Radon is the most serious harm to people in these hazards. Radon is a radioactive inert gases, and its half-life is only3.8days, is an important carcinogens. Waste rock piles radon governance is particularly important.From the measurement of the radon exhalation rate summary classification by the determination of the need for ventilation and the characteristics of the surface to be measured radon exhalation rate measurement method is divided into full-Lane dynamic method, Lane static method, local dynamic, local static method, and the four methods described in detail, the local static method is suitable for measuring radon exhalation rate of the waste rock pile surface analysis. Elaborate on waste the rubble surface radon precipitation mechanism, based on Fick’s law of diffusion, derived waste rock pile surface under steady-state radon exhalation expression obtained surface radon exhalation rate and waste piles, waste rock piles density, porosity, pressure, temperature differences,226Ra specific activity and other factors are positively correlated, negatively correlated with saturated humidity, temperature and other factors.A x mine waste rock piles as the research object, select the silty clay and viscous loess is cover experimental studied. Examine radon exhalation rate in the case of different coverage thickness both two covering materials, single-layer and multi-layer cover system covering the relationship between the expression of the thickness and surface radon exhalation rate is derived based on dual-zone theory, covering the test showed the feasibility of this theory. The cost of waste rock piles radon governance-benefit analysis, give full consideration to the population distribution around the level of protection of the waste rock, the waste rock piles radon exhalation rate measurement and cover thickness optimization analysis. The results show that the coverage optimal thickness and coverage of experimental parameters A and B, the thickness of the cover unit material costs required lambda not cover waste rock piles surface radon average precipitation rate jt public annual collective dose equivalent and waste dumps, governance after the average radon exhalation rate the ratio Ks and unit collective dose monetary value of alpha, the only people who know the value of the above five parameters can calculate the optimal cover thickness.The the waste piles cover densities optimization analysis results:When alpha=1$, silty clay and viscous loess optimal cover thickness of51.0cm and50.8cm; when alpha=20,000, powder the thickness of the clay and viscous loess optimal coverage of70.5cm and72.5cm.The study covered retired uranium mine waste rock piles optimization of the thickness of the reference value and the reference.