NPC vs bureau

NPC and bureau both are nouns.

Word	Noun	Adjective	Verb	Adverb
NPC	Yes	No	No	No
bureau	Yes	No	No	No

As nouns, bureau is a hypernym of NPC; that is, bureau is a word with a broader meaning than NPC:

NPC: an agency that serves as the focal point for all Intelligence Community activities related to nonproliferation of weapons of mass destruction and their missile delivery systems
bureau: an administrative unit of government

Other hypernyms of NPC include agency, authority, federal agency, government agency, office.

NPC (noun)	bureau (noun)
an agency that serves as the focal point for all Intelligence Community activities related to nonproliferation of weapons of mass destruction and their missile delivery systems	furniture with drawers for keeping clothes
	an administrative unit of government