Rapid Measurement of Radon Daughters Concentrations in Allouga Uranium Exploration Gallery, Sinai, Egypt

Radon gas and radon daughters concentrations were measured by active techniques using two instruments: EDA( RDA-200) and Tri-Met-372. The measurements were carried out during the month of June in a tunnel network at Allouga area, west central Sinai. In the ventilated sector (16 stations), the average tunnel air temperature was 24.4 ± 2.2 degree c and average relative humidity 38%. The radon gas concentrations using calibrated Lucas cell ranged 3.3-22.8 pCi/1 with an average of 11.9 pCi/1. The radon daughters concentration using Tri-Met-372: Kusnetz method range 0.01 -0.36 Wl and average 0.1 WL and Modified Tsivoglou method range 0.01-0.38 WL and average 0.1 WL. The results of the EDA(RDA-200) are :Rolle method range 0.01-0.29 WL and average 0.13 WL, Kusnetz method range 0.01-0.31 WL and average 0.12 WL, and Tsivoglou method range 0.02-0.41 Wl and average 0.15 WL. These reported averages estimated by the different techniques are consistent within the statistical errors. In the non-ventilated sector (12 stations), the average tunnel air temperature was 22.2±0.4 degree and average relative humidity 70%. The radon gas concentrations range 313-1348 pCi/1 and average 786 pCi/1. The radon daughters concentrations using Tri-Met-372 :Kusnetz method range 1.4 -13.88 WL and average 7.21 WL. The results of the EDA (RDA-200) are : Rolle method range 1.04- 12.9 Wl and average 6.910 WL. Kusnetz method range 0.98 - 12.24 WL and average 6.92 WL, and Tsivoglou method range 0.92-12.09 WL and average 6.84 WL. The reported averages by the different methods are consistent within the statistical errors. It is clear that the non-ventilated sector presents occupational working hazard in these tunnels, and strict radiation protection measures should be undertaken such as industrial ventilation