Experimental study of the electrical charging of radioactive aerosols.
F. Gensdarmes, D. Boulaud, A. Renoux, European aerosol conference, 3-8 september 2000, Dublin (Irland).
In case of an accident within a nuclear power plant, radioactive aerosols are generally the main source of contamination. In such case, the knowledge of the aerosol charge distribution is necessary to modelling aerosol transport and deposition in the containment.
The electrical charging of radioactive aerosols is different from the charging of a non-radioactive aerosol. The experiments carried out by Yeh et al. (1976) showed that one can observe a positive self-charging of the radioactive aerosol, which is due to the emission of the charged particles (a or b). Several theories exist to predict the charge distribution of a radioactive aerosol (Yeh, 1976; Clement and Harrison, 1992). These theorie s show that the aerosol mean charge increase both, when the aerosol specific activity increase or when the ionisation rate decrease. However very few experimental data are available, making the validation of the existing theories not reliable.
The aim of this work is to carry out experimental measurements on the radioactive aerosol charge distribution. For this purpose, we have designed and realised an experimental device allowing to generate a standard radioactive aerosol of 137 Cs and to analyse its electric charge distribution in a stationary state.