FISSION is a playable word

fission Scrabble® Dictionary

verb
fissioned, fissioning, fissions
to split into parts
36 Playable Words can be made from "FISSION"
   2-Letter Words (10 found)
   3-Letter Words (11 found)
   4-Letter Words (10 found)
   5-Letter Words (4 found)
   7-Letter Words (1 found)