atomic reactor vs chain reactor

atomic reactor and chain reactor both are nouns.

Word	Noun	Adjective	Verb	Adverb
atomic reactor	Yes	No	No	No
chain reactor	Yes	No	No	No

As nouns, atomic reactor and chain reactor are synonyms defined as:

atomic reactor and chain reactor: a nuclear reactor that uses controlled nuclear fission to generate energy

Other synonyms of atomic reactor include atomic pile, pile.

atomic reactor (noun)	chain reactor (noun)
a nuclear reactor that uses controlled nuclear fission to generate energy	a nuclear reactor that uses controlled nuclear fission to generate energy