NUCLEI is a playable word

nucleus Scrabble® Dictionary

noun
pl. nucleuses or nuclei
an essential part of a cell
34 Playable Words can be made from "NUCLEI"
   2-Letter Words (7 found)
   3-Letter Words (11 found)
   4-Letter Words (11 found)
   5-Letter Words (3 found)
   6-Letter Words (2 found)