Estimated radioactivity of solid fossil fuels

Abstract

The average concentrations of the main natural radionuclides, that is, thorium, radium, uranium, and the 40K isotope, in the deposits of coal and oil shale in the world and in Russia, which were obtained by summarizing the most reliable published data, are presented. On the average, solid fossil fuels, which are used as power-generating and chemical raw materials, insignificantly influence the general background of natural radioactivity; however, solid fossil fuels from particular deposits and their processing products, especially, ash and slag, are characterized by increased radioactivity. Experimental data on the chemical species of thorium and uranium in brown and black coals and on their distribution between the solid products of coal cleaning and combustion are generalized. It is shown that some publications on the experimental estimations of the radioactivity of ash-and-slag wastes contain serious inaccuracies. Relationships that make it possible to quantitatively fly ash the radioactivity of slag and fly ash based on the radioactivity and ash content of burnt coals are proposed. Normative relationships for calculating the possibility of the utilization of solid fossil fuel production, cleaning, and combustion wastes with known radioactivity values in the production of building materials are given. Unfavorable effects on humans and the environment, which can occur during the production and processing of solid fossil fuels with different radioactivity, and basic measures for decreasing them to tolerance levels are demonstrated.