Cameco trying to fix water problems at MacArthur; Jerritt

Operations at Cameco‘s (cco-t) MacArthur River uranium mine in northern Saskatchewan were suspended on April 6 after water infiltration in a development drift overburdened the mine’s pumping system.

Cameco described the water inflow as being “marginally above existing capacity,” and said that miners had re-entered the mine to begin remedial work. The mine can pump about 550 cubic metres per hour, but about 600 cubic metres of water were flowing in per hour by the afternoon of April 7.

The company planned to install more pumps and increase the capacity of its water treatment plant.

The water inflow is in a drift providing access to an area slated for mining in about a year’s time. An area of poor ground in the drift failed but appears to have stabilized. There were no injuries in the incident.

MacArthur River is the highest-grade uranium mine in the world, and water from the workings must be treated before it is released to the environment. High-volume groundwater inflows can force radon gas into the workings, creating a health hazard for miners.

Some of the inflow water is being directed into other areas of the mine, which are being allowed to flood while other remedial action is taken. Cameco estimated that a concrete barrier to control the inflow could be put up in two weeks, and that the workings could be sealed off in about two months.

The company has about nine months’ worth of inventory available to cover production shortfalls. Martin Quick, vice-president of mining, says the block that would have been mined in the area would be developed from another direction.