No its actually factors of millions less per unit mass. Fossil fuels produce energy via combustion, so the fundamental limitation here is the laws of chemistry since it is a chemical reaction. For somewhat technical reasons which I won't bore you with chemical reactions max out at around 17 MJ/kg. Nuclear fission reactions have a theoretical limit somewhere between 80 and 90 MILLION MJ/kg.

If you've ever seen the comparison of tonnes and tonnes of oil compared to this tiny, pinkie nail sized bit of uranium that's why. Nuclear just packs way more of a punch since far more energy is contained in the nucleus as opposed to the electron shells.

Nuclear power is considered as an alternate or substitute to those sources. Also it contains low carbon emission when it is compared to other non renewable sources like oil and coal. And it has a higher intensity than fossil fuel.

No nuclear power has a higher energy intensity than fossil fuel.

Nuclear power is more intensive than fossil fuels

:)