Dewatering Of An Underground Uranium Mine In Saskatchewan, Canada

The Cigar Lake Project is an underground uranium mine under construction in Northern Saskatchewan, Canada. The test mining program at Cigar Lake Project demonstrated the effectiveness of artificial ground freezing to control water inflows. However an inflow event occurred on October 26th 2006 on the 465 level of an unfrozen section of the development. The inflow was hypothesized to be result of the of ground failure of a relatively thin (about 8 m) beam of weak, fractured rock exposed in the roof of the drift and being loaded from above by relatively high hydrostatic pressure (about 4.2 MPa). The mine was flooded as the result of the inflow event. This paper documents the various activities of remediating and dewatering the mine carried out over a three year period.