Some good news:

Uranium Seawater Extraction Makes Nuclear Power Completely Renewable

A few hundred thousand years of recoverable uranium is available in seawater, and technology improvements are making it economically feasible. Chemical adsorbtion nets are collecting about 6 grams of uranium per kilogram of adsorbent per fifty days, for a cost of about $200 per pound of uranium oxide… about twice the current market rate. And even at that rate, the technology exists to negate any argument about nuclear power being a limited energy source.

Enough uranium is available to also negate any argument against constructing a fleet of 4,000 ton Orion vehicles to conquer the solar system out to Ceres.