There is enough uranium on Earth for getting all our current power for millions of years. (source: wikipedia)
There just isn't much at current prices, but fuel costs are not significant so prices cam rise.
There just isn't much at current prices, but fuel costs are not significant so prices cam rise.
With that assumption, fission can last for a very long time if we get uranium from the oceans, and burn it in fast reactors. The oceans hold four billion tons of uranium, and with fast reactors we'd use it a hundred times more efficiently than we do today.