Radioactive Dog

[TexasRanger]

I'm looking for a movie made in either the 80's or early 90's. From what I remember, there was a nuclear plant or research facility, with an older security guard, who I think has to leave behind a white puppy. A few years later the pup is full grown and from what I remember looks like a wolf. The dog gets out and ends up mating with this boys dog. I remember the dog dies or is killed soon after giving birth and the pups run off. I also remember the dog being killed in the end by a  beam/air vent falling off the ceiling. Thanks.

[Derf]

Sounds almost like Watchers, a 1988 Corey Haim movie based on a Dean Koontz novel. It's been a while since I've seen it, though, so I might be wrong.

[Javakoala]

May not be the right movie, there's the amazing Atomic Dog http://www.imdb.com/title/tt0147857/