Activity and Potential Alpha-energy of 222Radon and 220Radon-daughters in Different Air Atmospheres

Abstract

A simple model is described to estimate the activity balance of Rn- and Tn-decay products in a turbulent mixed air volume in the steady-state equilibrium, taking into account the attachment to aerosol particles and the removal of activity by ventilation and wall deposition. On the basis of this model the principal relationships between these parameters and the degree of radioactive disequilibrium, the fraction of free atoms or ions and the concentration of potential a-energy in the air are calculated and discussed, especially with regard to the conditions in uranium mines. The concept of potential a-energy is transferred also to Tn-daughters. The results will be a useful guidance to estimate the relation between the inhaled potential alpha-energy and the lung dose of workers in uranium and fluorspar mines.