atomic pile vs atomic reactor

atomic pile and atomic reactor both are nouns.

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

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

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

Other synonyms of atomic pile include chain reactor, pile.

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