http://en.wikipedia.org/wiki/Peak_uraniumThe European Commission said in 2001 that at the current level of uranium consumption, known uranium resources would last 42 years. When added to military and secondary sources, the resources could be stretched to 72 years. Yet this rate of usage assumes that nuclear power continues to provide only a fraction of the world’s energy supply.
If electric capacity were increased six-fold, then the 72-year supply would last just 12 years.