One of the world's largest uranium producers is warning that uranium could be in shorter supply than most people realize.

Tim Gitzel, the CEO of Saskatoon-based Cameco Corp, told investors in Toronto earlier this week that there is potential for supply shortfalls.

"We've seen 93 net nuclear reactors being built by 2020 so that obviously demands more uranium; right now there are not many new mines being built. There's a Russian HEU agreement that's in place that's ending in 2013 and that will take a lot of uranium off the market so we see the demand growing and supply tight."

Uranium prices have fallen 23 per cent since an 8.9-magnitude earthquake and ensuing tsunami rocked Japan in March and contributed to the meltdown of the Fukushima nuclear plant. That crisis led countries around the world to reexamine their nuclear energy programs, and Germany announced it would close its reactors by 2022.

But Gitzel says the end of the Russian deal to supply uranium from decommissioned atomic warheads means uranium prices are likely on their way up.