Correlation between the equilibrium factor F and the relative concentration of radon daughters in mine air

Two methods are presented for estimating the relative concentration of radon daughters in mine air when only the value of the equilibrium factor (F) is known. The first method, using correlations between calculated F values and measured relative concentrations of radon daughters, is based on results of many measurements made in U.S. uranium mines. The second method, based on the theoretical consideration of the mechanism and factors forming the dynamic equilibrium, includes calculations involving ventilation procedure and aerosol attachment process in mines. Results obtained by both methods were compared and found to be more or less consistent with each other. The correlation method was found to be easier and more exact. (author)