TORONTO (miningweekly.com) – Production from Cameco’s Cigar Lake project, located in the uranium-rich Athabasca basin, in northern Saskatchewan, would be delayed to the first half 2014, after the company on Monday announced that it would need to complete additional work at the project.

Construction of the Cigar Lake mine was reported to be 97% complete and commissioning of mining systems was well advanced.

However, during commissioning of the underground ore handling facilities in the mine, Cameco had identified additional work that would delay jet boring in ore. Based on current information, Cameco said it expected to begin ore production during the first quarter of 2014.

Ore from Cigar Lake will be processed at the McClean Lake mill, which is majority owned and operated by Areva Resources Canada.

Areva had also advised that further mill modifications were required and that the mill was expected to begin processing Cigar Lake ore by the end of the second quarter of 2014.

As a result of these developments, Cameco will not meet its forecast production of 300 000 lb of triuranium octoxide from Cigar Lake during 2013.

"Cigar Lake is among the most technically challenging mining projects in the world and we continue to make solid progress," Cameco president and CEO Tim Gitzel said.

Cigar Lake was originally expected to open in 2007, but was delayed twice by flooding. The deposit occurs at depths ranging between 410 m to 450 m below the surface where water-saturated Athabasca sandstone meets the underlying basement rocks. Due to geological conditions, it is necessary to freeze the deposit and surrounding rock to improve the ground stability and prevent groundwater inflows to the mine.

The jet boring mining method was selected for the Cigar Lake deposit after extensive testing. Operated from tunnels in the basement rock below the orebody, the jet boring mining system would use high-pressure water jets to mine out cavities in the orebody. A mixture of ore and water would then be piped away from the cavities to underground processing circuits, where it would be ground and thickened and pumped to the surface for transportation to the McClean Lake mill for processing to uranium concentrate.

Cameco also said the capital cost of the Cigar Lake project would not be materially impacted by the additional work required at the mine. Based on preliminary information, the capital cost of the mill modifications was also not expected to be material.