'Temperature' is really just a statistical construct. Thermal energy is a sum of kinetic energy of all the moving massive particles in a given region. You can have a colder area that still contains fast enough neutrons to trigger fusion, but just less of them than in a 'hotter' area in a bomb, for example. But all things being equal, more neutron flux at the appropriate energy/velocity per neutron will equal more fission interactions.

bikedork5000t1_j4quv9z wroteReply to comment by

iksbobinIf nuclear fission in U-235 causes the atom to be split into 2 smaller atoms (such as Kr-92 and Ba-141) then how is it that U-236 is produced as waste since the U-235 was just split into smaller peices?byIan98766'Temperature' is really just a statistical construct. Thermal energy is a sum of kinetic energy of all the moving massive particles in a given region. You can have a colder area that still contains fast enough neutrons to trigger fusion, but just less of them than in a 'hotter' area in a bomb, for example. But all things being equal, more neutron flux at the appropriate energy/velocity per neutron will equal more fission interactions.