Evaluation of inhalation exposure contributed by backfill mill tailings in underground uranium mine

Abstract

Radon and its short-lived decay products are the most important contributors of inhalation exposure to ionizing radiation in uranium mines. This paper describes the assessment of inhalation exposure potential of backfill mill tailings in Jaduguda uranium mine. The inhalation exposure of the miners to radon daughters in nine stopes was estimated based on the measurement of radon exhalation rate from backfill tailings, airflow rate, occupancy period and equilibrium factor in the stopes. The maximum inhalation exposure in the stopes was worked out to be 0.19 WLM year−1, which is about 5 % of the prescribed limit of 4 WLM year−1 for the miners recommended by the International commission on radiological protection. Thus, it may be concluded that the inhalation exposure of miners to radon daughters contributed by backfill mill tailings is not significant in a well-ventilated uranium mine extracting low-grade uranium ore.