某退役铀矿山放射性现状调查及评价OA

With the continuous growth in the number of decommissioned uranium mining and metallurgy facilities worldwide,the prevention and control of radioactive environmental pollution have emerged as a critical issue for the sustainable development of the nuclear industry.This study investigates the characteristics of radioactive pollution in a decommissioned uranium mine,aiming to clarify the sources of pollution and the current status of radiation levels.The results indicate that after the closure and decommissioning treatment of the mine,only the collapse area met the decommissioning treatment requirements.The radon exhalation rate and gamma(γ)radiation dose rate in the waste rock dump,open-pit mine,industrial site,and tailings storage facility all exceeded the regulatory limits specified in GB 14586-1993.The specific activity of 226Ra in the surface soil exceeded 248.9 Bq/kg(calculated as the local background value of 68.9 Bq/kg+180 Bq/kg),and the content of natural uranium(U)exceeded 30 mg/kg.Buildings,ore transportation roads,streams,and equipment pipelines within the mining area were contaminated to varying degrees.The concentration of natural uranium(U)and manganese(Mn)in the pit water exceeded the discharge standard limits.The individual effective dose from internal irradiation by radon and its daughters and the individual effective dose from external gamma(γ)radiation were both greater than 0.1 mSv/a,necessitating urgent decommissioning and remediation measures.