Occupational monitoring in a mine and processing plant of uranium in Brazil

This work describes the activities of occupational radiological monitoring of workers from Uranium Concentrate Unit - URA, from 1/1/2003 to 12/31/2003. In this period 1657 Licenses to Work with Radiation (LTR) were issued, covering 4548 workers. 157 of these were visitors and 21 were inspectors. For external exposure the location with the highest dose rate was the stocking DUA, with an average of 3.10 x 10-2 mSv/h, followed by mina (drilling) with 1.13 x 10-2 mSv/h and decontamination with 0.74 x 10-2 mSv/h. With respect to internal exposure the area with the highest dose was the packaging of DUA with 1.33 x 10-2 mSv/h, patio of crushing with 0.40 x 10-2 mSv/h and the leaching patio with 0.36 x 10-2 mSv/h. For external exposure, the operating function which obtained higher dose group was process operator with 2.35 man-mSv, driver with 1.54 man-mSv and servant with 1.13 man-mSv. For internal dose, the function with highest dose group was the drilling helper with 4.28 x 10-1 man-mSv, followed by process operator with 0.46 x 10-1 man-mSv and finally the driver with 10 x 0.22-1 man-mSv