Radiation hazards of uranium mining and milling
Australian Atomic Energy Commission
As well as the need to control the more conventional hazards associated with any mining and milling operation, special care must be exercised in the mining and milling or uranium because of the radioactive nature of the ore. Uranium ore, though only mildly radioactive, contains a complex mixture of radioactive isotopes, the behaviour of which during each phase of the mining and milling process, determines the controls that must be established to ensure safe working conditions. This paper examines each of the radiological problems that arise in these processes and explains their scientific background. The radiation standards that should be applied and the procedures that should be adopted to minimise radiation exposure to all persons are set down in the Australian 'Code of Practice on Radiation Protection in the Mining and Milling of Radioactive Ores 1975'. If the requirements of this code are adhered to, the radiological safety of miners, mill workers and members of the public can be assured. The major operational requirement is to ensure that exposure of miners over their working lives to radon and its daughter products does not lead to an unacceptable increase in their chance of contracting lung cancer. Studies on the incidence of lung cancer amongst underground uranium miners indicate that this risk will be small if lifetime exposures are kept below about 120 'working level months', even amongst underground miners who smoke cigarettes. The risk is much smaller again for miners who do not smoke. Other hazards that must be controlled are exposure of miners and mill workers to external radiation and to dusts containing long-lived radioactive α emitting isotopes. Finally, the solid waste products from the mill (the tailings) which contain most of the naturally occurring radioactivity, must be properly impounded and after closure of the mill, stabilized to ensure long-term containment. Access by the public to the stabilized tailings must be controlled and habitation within the controlled area prohibited.
Radiation hazards, Inhalation, Lungs, Radon, Uranium
Fry, R. M. (1975). Radiation hazards of uranium mining and milling. (AAEC/IP9). Lucas Heights, NSW: Australian Atomic Energy Commission.