Question: how much energy is required for nuclear fission?
Answer: The total binding energy released in fission of an atomic nucleus varies with the precise break up, but averages about 200 MeV* for U-235 or 3.2 x 10-11 joule. This is about 82 TJ/kg. That from U-233 is about the same, and that from Pu-239 is about 210 MeV* per fission.