I came over this term and, while I have looked up the words separately, I am not sure of the meaning in a compund noun. Does it has anything to do with nuclear power, or is it more like the meaning of the nuclear family?
<< moderator note. Unless we have a complete sentence, a source if it is not one you have written yourself, and some context (see The Longer Guide to English Only), I'm afraid that this thread will be deleted >>
Hey Andy - My guess is that the term is from anthropology/sociology. It looks much odder than it is: it's simply a small settlement with all the dwellings clumped together in a central nucleus. (So the same use of the word "nuclear" as in "nuclear family," but talking about a small town rather than a family.
But I would understand if you considered this to be wild speculation and deleted it.