Assessment of Discharged 222Rn at Surface from Ventilation Shafts of Underground Uranium Mine at Narwapahar in India

Measurements of atmospheric release from underground uranium mine at Narwapahar in state of Jharkhand has been done to assess the discharged ²²²Rn at surface from ventilation shafts of mine. Annual volume of atmospheric discharge has been estimated around 6 × 10⁹ m³ from ventilation shafts of mine with associated radon (²²²Rn) activity around 2.3 × 10¹³ Becquerel. Such a huge amount of radioactivity discharge in open atmosphere through underground uranium mine is always under consideration to assess the exposure of public residing in surrounding villages, if any. Realizing the non-negligible health hazards due to radon exposure, the present study has been carried out to measure the radon concentrations in surface discharged air. A portable radon-measuring device (Alpha-guard) is used to determine the radon levels. Alpha-guard is used in diffusion mode for the measurements of radon concentration in the vicinity of ventilation shafts of the U-mine. The study reveals that the discharge of radon from mine exhaust is confined within 100 m of the discharge point of the mine (in no man area within mine premises) and it does not affect the inhalation hazards to inhabitants residing in public domain in nearby villages.