Exposure to short-lived radon daughters: comparison of individual and ambient monitoring in a French uranium mine

The components of the radiological hazard in uranium mines are: exposure to radon and its short-lived daughters; exposure to long-lived ore dust; and external irradiation. With usual ventilation rates, the dosimetry relative to the first component only requires to know each miner's exposure to a potential energy of short-lived radon daughters, (EXP α). Presently in France, (EXP α) is determined monthly from radon concentration measurements. This is an indirect method based on ambient monitoring. After technical improvements achieved during the last years it is now possible to measure (EXP α) directly with an individual portable monitor developed by the CEA. The purpose of this study is to analyze and compare monitoring results obtained by these methods