TRANSPORT MODELING IN THE NATURAL ANALOG STUDY OF THE CIGAR-LAKE URANIUM DEPOSIT (SASKATCHEWAN, CANADA)

A near-field release model is developed both conceptually and mathemat ically. The model is tested against known helium release from the Ciga r Lake uranium ore deposit. The release and transport of various aqueo us species (including some radionuclides) in the deposit are studied b y using this model. The uranium release rate predicted by the model is extremely low, which is consistent with field observations. In modell ing the release of three other radionuclides (H-3, C-14 and Cl-36), th e in situ generation and decay are taken into account. The measured co ncentration gradients of hydrogen was used to estimate the net rate of radiolysis. The simultaneously formed oxidising species are found in sulphates formed by oxidation of sulphides. There is a good agreement of the estimated rate of formation of the reducing component hydrogen and the oxidising component as found in the sulphate.