Radiation Protection Dosimetry 82:229-232 (1999)
© 1999 Oxford University Press
Studies on the Equilibrium of 220Rn (Thoron) and its Daughters in the Atmosphere of a Monazite Plant and its Environs
Studies carried out at the Monazite processing plant of Indian Rare Earths Ltd, at Udyogamandal, Kerala have shown that the mean ratio of the airborne concentrations of 212Bi to 212Pb were 0.20 ± 0.08 and 0.55 ± 0.21 for the process plant atmosphere and outside atmosphere respectively. The mean equilibrium factor, F, for 220Rn and daughters in the plant is found to be 0.003 ± 0.002. This value is 6 times lower than the F value for the outside atmosphere which is 0.02 ± 0.01. The equilibrium factors determined facilitate internal dose estimation in monazite and thorium processing plants.