Actually the peer reviewed science shows that nuclear energy has no net energy return. What this means is every dollar spent on nuclear energy is wasted. The study uses industrial standards for process measurement as a basis.
The site you linked to is bunk. They're using the 2nd law of thermodynamics to argue against mined resources. Let's see what they say: "From the Second Law follows that the generated amount of useful energy from mineral energy sources is insufficient to compensate for its coupled entropy generation, even if all useful energy would applied to that purpose." It's not possible for uranium mining to decrease entropy in the universe, so obviously it's not economically viable! You could say the same thing for breathing.
We can defeat gravity. The problem is the paperwork involved.