Very common at the national labs. Someone with background in nuclear and geology or civil/geological will have an easy time finding a job. Waste disposition a big part of the field and 25% of nukes will work on the back end of the fuel cycle at some point in their career.
EM "owns" about a third of INL and their jobs are never done. If you can get and keep a clearance then you'll be set for life.
You can do research at INL too, civil background and MS Nuclear is more than sufficient to do work there. You'd probably need more than that at the NNSA labs though. One thing to bear in mind is that any research work you do there will never get "built". It's a lot of paper studies that end up on a shelf.
I'll PM with more info later.