While Wiktionary has "A device which uses atomic energy to produce heat" as one definition, other dictionaries all include the ability to regulate/control/sustain a nuclear reaction. I'm inclined to agree with them.
Well, we all understand that a nuclear warhead is technically a reactor but not what we mean in practice when we use that word. The typo in the article was just a bit unfortunate.
It's only technically a reactor if you accept Wiktionary's definition of what a reactor is, instead of any of the "real dictionaries". I'm of a mind that setting off an uncontrolled nuclear reaction doesn't make something a reactor.
