[en] We have extended a simple, infinite-cloud, precipitation-mechanism model of thundercloud electrification to include effects due to the presence of radioactive aerosol particles. These effects involve ion generation, currents due to motions of ions and charged aerosol particles, and collection of ions and aerosol particles by hydrometeors and cloud droplets. Our conclusion is that an ion-pair generation rate G equal to or greater than 1012m-3s-1 will prevent significant electric-field growth