INTRODUCTION• Uranium mining is treated differently than other mines!• The environmental Impact Statement (EIS) during approval process• Higher level of community concern in relation to uranium mining than with other mining activities• Lack of trust consultants/contractors EIA reports• Increase cost and Delays – The Community perceptions; – The actual and perceived risks
OBJECTIVES OF THIS PRESENTATION(I)BRIEF OVERVIEW OF URANIUM MINERALIZATION IN TANZANIA(I)TO ESTABLISH A PRELIMINARY BASELINE RADIOACTIVITY LEVELS
U MINERALIZATION IN TANZANIAGeosurvey International in 1976-1980 carried out uraniumexploration on country wideFurther ground follow-up was undertaken by Uranerzbergbau ofGermany in 1978-82 Airborne geophysical survey comprising magnetics, radiometricand electromagnetic methods was carried out all over the countrySpacing of the flight lines was 1 km and tie lines 10 kmPotential for follow up work suggested:Sandstone and siltstone of Karroo System;Igneous/intrusive type; -Carbonatite; and -Intra-intrusive rocks.Hydrothermal type; - Unconformity vein type in Ubendian and Karagwe-Ankolean SystemPhosphate rocks; Superficial calcrete and mbuga deposits; andRadioactive beach sand.
Selous Game Reserve (SGR)U Anomalies• Tabular Sandstone-hosted uranium deposit• The SGR is the largest game reserve in Africa and includes two national parks• It was declared a natural world heritage site in 1982 by UNESCO• The discovery alarmed the public and encounters oppositions from public and civil societie• The baseline radiological studies were conducted by non partial audience to characterize the initial conditions
LOCAL GEOLOGYThe local geology of the project is located in large intracratonic basin filled with clastic sedimentsThe uranium mineralization is a tabular occurs intestinally in the course sandstones and conglomerate channelThree trap lithologies namely: (i) Arkose unit containing carbonaceous debris, carbonaceous siltstone rip-up and mercasite/pyrite concretions (ii) Permeable coarser sandstones with marcasite concretions and fine joints and clay development in the matrix of permeable stratigraphy (iii) The oxidized organic rich outer zones where mineralized layers exposed on the sides of the steep hillsThe rich outer zones are caused by uranium concentration andupgrading as a direct result of reducing environment caused byincrease in organic materials
Why?Independent information for:Regulatory authorities government AuthoritiesEnvironmentalistThe public,Politicians; andGovernment officials
High Purity Germanium (HPGe) detector was usedRelative efficiency of 55% and resolution of 1.70 keV at 1332 keV energy of 60CoThe detector chamber was shielded with three layers of copper, cadmium and Lead of 30 mm, 3 mm and 100 mm thick, respectively Soil, sediment and surface water, food crops and Vegetations commonly feed by wild animals samples were measured The performance of the system was validated using IAEA reference materials like soil 375, the experimental values were within ± 5 %
ACTIVITY CONCENTRATION IN SOILMaximum activity concentration of 238U and 232Th and 40K in soil samples compared to the control (7*)Any significant deviation from these values in future may be attributed to the uranium mining processes
Activity Concentration in sedimentsThe activity concentrations of 238U and 232Th and 40K radionuclide were higher than the control samples As expected, the activity concentration of the 238U, 232Th and 40K in the sediment samples were much higher than those found in control samples
Activity Concentration in waterThe activity concentrations 238U in the samples from Mkuju were slightly higher than the mean value in control sampleThe activities of radionuclides in the analyzed water samples were comparableThe activities were also in the same range as the activity in the control sample The samples from wet Mkuju River had slightly higher activity concentration than other three samples
Activity Concentration in food cropsThe results show highest average activity concentration of238U, 232Th and 40K in from maize samples while cassava tuberand millet grains have lowest activity concentration.
Activity Concentration in wild vegetation feed by wild animals The results showed elevated activity concentration of radionuclides 238U and 232Th in weeds sampled from riverbank than in grass Wild fruits showed lowest activity concentrations for all radionuclides The activity concentration is typical grass shows lowest activity concentrations which are commonly fed by animals d animals
6. CONCLUSIONThe baseline information presented compared withenvironmental data collected once the mine isoperational, will be used as a basis to evaluate potentialenvironmental impacts of the mine operationsThe radiological baseline studies are important to build public trust about the industryThe Wildlife Act of 2009 has weakened the legal basis for World heritageHowever, the status of to whether mining and milling activities will take place or not awaits UNESCO discretion