Operational limit for uranium ore dust applicable to Uranium Complex at Jaduguda

The operational limit for uranium ore dust applicable to the workers at the Uranium Complex at Jaduguda (India) has been rederived considering the experimental findings regarding the aerosols particle size and activity distribution thereof, during different operations, solubility rate of uranium ore dust in lung serum simulant and changes in the concept of radiation protection. The derived operational limits for various operations range from 48.6 p Ci.h/1 to 69.3 p Ci.h/1. The operational limits are calculated considering an activity median aerodynamic diameter (AMAD) of 1 μm. It is impractical from operational point of view to adopt several standard values in one place when the radionuclides under consideration are the same. In the case of Jaduguda Uranium Complex, the range of values being small, a figure of 60 p Ci.h/1 can be adopted for day to day plant operation. (B.G.W.)