Modeling of radon and its daughter concentrations in ventilated spaces.

Discusses sources of radon in buildings and the prediction of levels of radon and daughters. Derives differential equations governing the decay and venting of radon and its daughters. A computer program based on these equations has been written to predict radon and daughter concentrations, total potential alpha energy concentration and equilibrium factor. The program can account for time dependence of ventilation and emanation rates and is readily used by building designers. Gives examples of sample calculations and shows that potential alpha energy levels in buildings with air change rates of 0.2 to 0.5 changes per hour, can surpass 0.1 working level.