Reduction in air activity and occupational dose at the Mineral Separation Plant, IREL OSCOM

Monazite concentrate in the non-conducting fraction is fed to High Intensity Roll Magnetic Separator (HIRMS), followed by Rare Earth Drum magnetic separator (RED) to separate the feebly magnetic monazite and weak magnet garnet fractions. After rejecting the garnet fraction, the monazite concentrate is fed to Semi Lift Magnetic Separator (SLMS) and then to the air tables, where monazite gets concentrated up to 65%. The air activity levels, due to 232Th, in the operational area show substantial reduction by two orders of magnitude between 2003 and 2010. Corresponding reduction in the overall exposure in the plant between 2006 and 2010 has also been significant, by a factor of 3, when the new system was introduced. The above modification in the monazite processing has also significantly reduced the external exposure in the Mineral Separation Plant, details of which will be discussed in the paper. Technological improvements have always resulted in substantial occupational and environmental dose reduction in the front end of the nuclear fuel cycle. As technology further improves radiation exposure in this area is bound to show more reduction in the years to come