non-fissile

adjective

1. capable of being split or divided; cleavable.
2. Physics.
   1. fissionable.
   2. (of a nuclide) capable of undergoing fission induced by low-energy neutrons, as uranium 233 and 235.

adjective

1. British capable of undergoing nuclear fission as a result of the impact of slow neutrons
2. US and Canadian another word for fissionable
3. tending to split or capable of being split

adj.1660s, from Latin fissilis “that which may be cleft or split,” from fissus, past participle of findere (see fissure).