Occupational radiological aspects of the downstream processing of mineral sands

The downstream processing of some of the products of the mineral sands industry may involve substantial worker exposure to external and internal sources of radioactivity. The relative magnitude of the various pathways for occupational radiation exposure are reviewed in the light of published information and these are contrasted with criteria proposed by various proponents of plants to be established in Australia. It is concluded that workers exposures in new monazite processing plants can be controlled to below 20 mSv y-1 provided careful attention is paid to intrinsic radiation protection, such as process equipment layout, selection and operation, ventilation, and engineering controls to minimise contamination. In existing plants reliance may need to be placed on secondary protective measures such as respiratory protection and job rotation to achieve satisfactory exposure control. 22 refs., 3 tabs., 1 fig