If you're comparing with solar, it seems fair to assume a level of energy usage that could reasonably be supplied by solar. We're not going to cover the planet in solar panels.

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.

I said "all our current power" and I mentioned my source.