Kess .. nuclear energy can only replace the fossil fuel we needed for power generation ..here are some facts to chew on i look'em up in the CIA FACT BOOK as of 2005
Electricity - production by source: fossil fuel: 81.7% hydro: 14.5% nuclear: 3.4% other: 0.3% (2001) i hope u get what am trying to say here from above chart .