In 2005, seventeen countries produced concentrated uranium oxides, with Canada (27.9% of world production) and Australia (22.8%) being the largest producers and Kazakhstan (10.5%), Russia (8.0%), Namibia (7.5%), Niger (7.4%), Uzbekistan (5.5%), the United States (2.5%), Argentina (2.1%), Ukraine (1.9%) and China (1.7%) also producing significant amounts.<53> Kazakhstan continues to increase production and may have become the world's largest producer of uranium by last year (2009) with an expected production of 12,826 tonnes, compared to Canada with 11,100 tonnes and Australia with 9,430 tonnes.<54><55> The ultimate available uranium is believed to be sufficient for at least the next 85 years<47> although some studies indicate underinvestment in the late twentieth century may produce supply problems in the 21st century.<56>
http://en.wikipedia.org/wiki/Uranium#Supply