Radium is the most significant contributor to dose in the mining effluents from uranium mining operations in the Areva portfolio and iron mineral / radium interactions are poorly constrained. The aim of this project is to define constraints on the environmental behaviour of radium in the presence of key Fe mineral phases. Preliminary work indicates that hydrous ferric oxide is reactive to Ra2+ and that the presence of counter ions (Ca2+, Ba2+) influences binding. Interestingly, reactivity of Ra2+ to goethite is variable with reasonably high retention reported; release of Ra2+ to solution during recrystallisation of ferrihydrite to goethite is also reported. Pyrite reactivity is again variable with chemically precipitated pyrite less reactive then microbially produced pyrite. Overall, there is a need to define Ra2+ / iron mineral interactions over a range of conditions relevant to U-mining legacy materials.
Prof. Katherine Morris (PI)
Prof. David Vaughan