The company said that the entire province has been experiencing a "significant negative trend in the pandemic" that has left Cameco uncertain for the mine's continuous operation as the pool of qualified workers dwindles.
"One of the most challenging trends we've had to navigate is the shrinking availability of workers in critical roles at Cigar Lake due to self-isolations, absenteeism and communities being on temporary pause for transporting workers due to the pandemic," president and CEO Tim Gitzel said, adding that the mine has had six positive cases recently.
"While the protocols we have put in place have to date allowed us to effectively manage these cases, there are broader risks we don't control. Therefore, we believe it is prudent to do our part to continue to protect our people and our operations from the increasing threats that are outside our influence."
The end of the stoppage will depend on how the pandemic develops. Cigar Lake will be maintaining a skeleton crew during the care and maintenance period who will be following increased protocols on-site.
Gitzel also noted that, due to the mine's suspension, it has planned to increase its market purchases to secure needed uranium to meet sales commitments.
"COVID-19 has taught us many lessons, including that the pandemic is a greater risk to uranium supply than to uranium demand," adding that its deliveries to date have not seen a material impact from the pandemic - and none are expected through the end of the year.
As of September 30, Cigar Lake had produced 2.3 million pounds (Cameco's share) of uranium concentrates in 2020. It does not expect it will reach its goal of 5.3M lb (its share) of whole-year 2020 production.
Cigar Lake, in operation since 2015, is owned by Cameco (50.025%), Orano Canada (37.1%), Idemitsu Canada Resources (7.875%) and TEPCO Resources (5%), and is operated by Cameco.
