Use of an Automated Fluxmeter Employing Solid-State Diffused-Junction Alpha-Detectors and a Meteorological Package to Determine Surface Radon Flux

Several radon fluxmeters have been designed to determine surface radon flux in uranium mines, tailings sites and other locations of interest. The fluxmeter consists basically of a chamber where radon gas is collected, and a data logger provided with standard RS-232 capabilities for interfacing with a microcomputer (Apple II). The fluxmeters are cylindrically shaped with sharp edges so that they can be partly driven into the ground with negligible disturbing effect on the material formation. The fluxmeter chamber is equipped with ¿-particle detectors and meteorological sensors to monitor radon gas levels, soil parameters and meteorological variables. The fluxmeters can be operated in a continuous fashion or in a discrete mode, and are fully programmable and automated. The apparatus has been extensively used in the field and is ideally suited for unattended, continuous, monitoring of radon gas levels and meteorological variables for extended periods of time. Some field data obtained with one of the fluxmeters are presented and the relevance of the data discussed. On the average the surface radon flux at the tailings site where the fluxmeter was installed was in the order of 20 pCi/m2s (740 mBq/m2s). However, much higher values were obtained depending on meteorological conditions and the conditions of the soil (tailings material).