Uranium jumped to US$26 per pound, a 2020 high.
Like many of its mining peers, Cameco is suspending Cigar Lake for at least four weeks due to the threat of COVID-19.
Cigar Lake partner Orano is suspending the nearby McClean Lake mill that is used to process ore.
The operations had produced 4 million pounds of uranium oxide so far this year, but Cameco said it was too early to assess the impact.
"We are in unprecedented and challenging times," Cameco president and CEO Tim Gitzel.
"In the face of great uncertainty, our first priority is to protect the health and wellbeing of our employees, their families and their communities. Our leadership team took a measured approach and weighed many factors in assessing the situation both globally and locally to make this decision, which takes into account the specific and unique circumstances at Cigar Lake, a remote, isolated fly-in/fly-out northern Saskatchewan operation."
Earlier this month, Canaccord Genuity analysts said in a decarbonising world, nuclear had an advantage as a "compelling zero emission, cost competitive (levelised cost per kWh 50% of unsubsidised renewables) and highly reliable (capacity plus-80%, regardless of reactor age) generation source".
"This, combined with the likelihood of life extensions at existing generators, means we are increasingly bullish on uranium demand," it said.
Canaccord is forecasting a 45% jump in uranium demand by 2035 and is forecasting a rise in price to $50/lb from 2025.
"While bouncing off decade lows, we note the sustained uptick (nine months) in long-term pricing to $35/lb," analysts said.
Canaccord favours ASX juniors Vimy Resources, Boss Resources, Paladin Energy and Peninsula Energy due to advanced projects in low-risk jurisdictions.