Can nuclear fission occur in any other element other than Uranium-235?
Yes, uranium-233 is really useful for fission, but not as abundant as U-235. Pu-239 is another good candidate for fission. U-238, the most abundant isotope in natural uranium, will also fission if used in the right type of reactor. For example, the CANDU reactor (the reactor design that canadians use), only uses natural, non-enriched uranium to operate. Thorium-232 will also fission. Th-232 and U-238 are actually known as “fissionable but not fissile”, which means that they can be used for fission, but they can’t be the only fuels in th reactor. If you were to use either of those two isotopes, you would also need a fissile material like U-235, U-233 or Pu-239. Now, Th-232 isn’t fissile, but it can be converted (in a breeder reactor) into U-233, which is fissile. This also goes for U-238, which can be converted into neptunium-239, which in turn could be converted to Pu-239 (fissile). If you keep going with this chain, Pu-239 can be converted into nonfissile Pu-240, absorb another neutro
