In my limited experience, I would say the Shipyard is 180 from Commercial Nuke Plant HP. I am thinking in the Shipyard you are dealing mostly with military contractors, Navy ELTs, NR, and NRC all rolled into one. I can imagine that sucking.
I think you will find a better world in commercial HP, but I will let you make that determination and I am sure more experienced shipyard folks and commercial HPs could assist you.
The closest you get to a shipyard availability in a nuke plant is a refueling outage and that is less than 45 days and there are no military bureaucrats/NR to deal with. There is time pressure, but I have not felt the pressure like I did back in the Navy.
In a nuke plant, Operations is typically the largest group. HP/Chem are typically the smallest. Do the math. I would say all would be good choices for advancement over the next 10 years as new plants come on line and older folks retire.
I am speaking from a non-Union perspective (whole nuther thread). In a non-Union plant, you don't have to officially worry about "seniority" and bidding on jobs, so a motivated hard charger may be able to move up faster (opinion only).
Also, in OPs, there is typically 2-3 years between license class, so you may have to wait a few classes before moving up.
There are so many factors, but I bet anywhere you could build your own career if you put forth the effort.