Paper engineering is more like chemical engineering; actually I think at some schools it is a focus of chemical engineering. Um... he might be able to get a chemistry engineers position, although I know here it seems we require environmental degrees or equivalent experience in the chemistry program for these positions... I could be wrong on that, though, I'm in computer engineering and so not that familiar with their requirements.
His management experience might apply, the not having nuke experience might hurt. Does he have a license? If he has one of those, in and out of the industry that should take him far, at the very least as a consulting engineer. It sounds like he has alot of possibilities.
Couldn't hurt to apply and I wish him the best of luck wherever he ends up!