Uranium mines, radioactivity

Care must be taken in handling radon, as with other radioactive materials. The main hazard is from inhalation of the element and its solid daughters which are collected on dust in the air. Good ventilation should be provided where radium, thorium, or actinium is stored to prevent build-up of the element. Radon build-up is a health consideration in uranium mines. Recently radon build-up in homes has been a concern. Many deaths from lung cancer are caused by radon exposure. In the U.S. it is recommended that remedial action be taken if the air in homes exceeds 4 pCi/1. 

The presence of radiation in the workplace - which is an inevitable consequence of the radioactivity of uranium - requires that additional safety precautions be taken over and above those observed in other similar workplaces. There are generally three sources from which radiation exposure may occur (i) radiation emitted from uranium ore in-situ and/or during handling (ii) airborne radiation resulting from the decay of radon gas released from the ore and uranium dust and (iii) contamination by ore dust or concentrate. Radiation levels around uranium mining and milling facilities are quite low - for the most part only a few times the natural background levels - and they decrease rapidly as the distance from... 

Busigin, A., A.W. van der Vooren and C.R. Phillips, Measurement of the Total and Radioactive Aerosol Size Distributions in a Canadian Uranium Mine, Amer. Ind. Hyg. Assoc. J. 42 310-314 (1981). 

This paper deals mainly with the condensation of trace concentrations of radioactive vapor onto spherical particles of a substrate. For this situation the relation between the engineering approach, the molecular approach, and the fluid-dynamic approach are illustrated for several different cases of rate limitation. From these considerations criteria are derived for the use of basic physical and chemical parameters to predict the rate-controlling step or steps. Finally, the effect of changing temperature is considered and the groundwork is thereby laid for a kinetic approach to predicting fallout formation. The relation of these approaches to the escape of fission products from reactor fuel and to the deposition of radon and thoron daughters on dust particles in a uranium mine is indicated. 

Beyond radioactivity, nuclear energy occurred spontaneously on Earth when sustained fission reactions developed spontaneously in the uranium mine of Oklo in Gabon in Africa, showing the path towards fission reactors about 2 billion years ahead. 

Blanchard RL, Fowler TW, Horton TR, et al. 1982. Potential health effects of radioactive emissions from active surface and underground uranium mines. Nucl Saf 23 439-450. 

Eadie GG, Port CW, Beard ML. 1979. Ambient airborne radioactivity measurements in the vicinity of the jackpile open pit uranium mine New Mexico. Report ISS ORP/LV-79/2. NTIS PB292379. 

Yang IC, Edwards KW. 1984. Releases of radium and uranium into Ralston Creek and Reservoir Colorado USA from uranium mining. In Barney GS, Navratil JD, Schulz W, eds. 185th meeting American Chemical Society Symposium Series 246. Geochemical behavior of disposed radioactive waste, Seattle WA, March 20-25, 1983. Washington, DC American Chemical Society, 271-286. 

Uranium. Uranium, neptunium, and plutonium are probably the most important actinides in assessment of the environmental risks posed by radioactive contamination. Uranium contamination is present at numerous sites contaminated by uranium mining, milling, and solution mining as described in previous sections. It is highly mobile and soluble under near-surface oxidizing conditions and thus presents an exposure hazard to humans and ecosystems. 

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