ABSTRACT
It is important to dispose the tailings hermetically, using bottom liners and caps on tailings, to last for 200 to 1000 years. In situ bioremediation technologies are being developed to optimize the containment process. In all cases, monitoring of groundwater has to be carried out for tens of years. There is need to understand the role of microorganisms on the behaviour of radionuclides and heavy elements in regard to the tailings. We know that while iron and sulphur-oxidising bacteria may cause the rise in radionuclide concentrations through acidification, metal-and sulphate-reducing bacteria bring about the precipitation of radionuclides, through the reduction of U6+ to U4+.
