Considerations about TENORM: a study case on niobium facilities

Two niobium mining facilities located at two different geological settings were selected as case studies for assessing the radiological impacts associated with mining and milling activities. The impacts were assessed both for operational and post-operational (future unrestricted use of the area) scenarios. The work methodology encompassed sampling and analysis of different materials along the operational process, including wastes, effluents and by-products, mass balance calculations, and dose assessment. The exposure scenario considered during the operational phase included the land use by hypothetical groups of members of the general public. In the case of post-operational phase the possible occupation of contaminated areas was considered. The results pointed out that during the operational phase of the investigated industries no relevant impacts could be attributed to them. However, in the case of the potential occupation of the contaminated areas where the wastes are being deposited, the unrestricted use of these areas cannot be accepted in terms of the relevant radiation protection requirements.