Continuous monitoring of the artifical beta-activity of the aerosol in real time

We have constructed a system to monitor the artificial beta-activity ofthe aerosol continuously in real time around nuclear power plants. The smaller releases of artificial radionuclides from the nuclear power plants can be lost in fluctuations of the natural background of the beta-activity of the aerosol, in case that the beta-activity of the aerosol is only measured. The method to discriminate artificial beta-activity and natural beta-activity of the aerosol is based on the almost constant ratio of the natural alpha- and beta-activity of the aerosol. The detection limit of this system is below 3Bq/m3. (author) 4 refs.; 6 figs.; 1 tab