Newer reactors have very redundant security systems, and are very safe. Again, its up to the US gov't (NRC) to allow these to be built on US soil, so that nuclear power will become a major factor in energy production.
And no, new nuke reactors are far safer than oil. See BP oil spill, and find me a nuclear reactor incident on equal scale inside the US.
A SHIT TON. Probably close to 60%