Depleted uranium

This is a video of Bill Gate’s recent presentation at TED where he argues that the most promising way of reaching zero carbon footprint by 2050 will be through terra nuclear energy. Gates claims that, because terra nuclear plants will be burning U238 (in contrast to the current U235), they will have not only little to no waste, but will actually be fueled by the depleted uranium stockpiles from our current and past generation of nuclear power plants.  Thus the terran nuclear power-plants will be not only extremely efficient and economical, thereby bringing down the average price of energy, but will also be guaranteed uninterrupted supply of nuclear fuel in the form of our present day copious amounts of depleted uranium stockpiles.  This in turn, says Gates, will provide us with nuclear fuel for hundreds of years to come and [...]