The Navy uses Pressurized Water reactors which seem to be a fairly common design in commercial use as well (according to Wikipedia, anyway). Which means a lot of how things work would be similar, and you'd just have to learn the specific systems for how that plant operated (i.e. the designs and how the cooling, electronics, power generation, etc. worked)
I would imagine there would be a lot of overall similarities in core principles and operations, but some specific systems would work differently being on land and likely generating a lot more power + having other requirements for discharges and cooling etc, vs. a seagoing vessel.
One of the things that was apparent is purpose. A commercial reactor is a profit making device whereas a Naval reactor is part of a war machine. In the former you end up with complexity designed to save cost, where the later favors simplicity and extra cost to ensure stability. That is not to say commercial is unsafe, but the motive behind design is different and hence leads to different results and design criteria.
From what I can tell, I haven't worked a commercial reactor but commercial reactors are toys in comparison to their Naval counter parts. Going back to your land based vs sea based comparison. Refueling a land based reactor is trivial compared to cutting into a hull that needs to sustain high pressure underwater. This requires extra design in poison placement and fuel placement to achieve a longer life cycle measured in decades not years. The material barely touches on this and no where near the level of detail you get in the full NNPP schooling.
Commercial plants are very well aware of the training and experience that Naval operators get. I have many friends that went commercial. In the commercial world you don't shutdown or startup a reactor very often and hence you have specialists to handle that task. In the Naval world you do this every time you pull into a port. A Naval operator with 6 years experience has most likely done a few hundred cycles compared to a civilian at the same number of years only doing startups measured in the tens. So order of magnitude difference.
Startup of a reactor is one of the most difficult controlled chaos events in which you calculate expectations, move rods, and monitor activity to make sure everything is safe. A quick study of the neutron life cycle illustrates the simple fact that you don't know the state of the reactor in current state, but only in what it might be in future state. So you guide future state with understanding of current state and what might influence that state. You have to understand the Xeon poison over the last hours of operation and when that is going to decay among other things. It's not rocket science but it does require an attention to detail.
In full disclosure my first 10 minutes on a live reactor resulted in a mental breakdown. I knew all of the formulas and what I was suppose to do, but at the first time I had to move the rods I just brain farted out of nervousness. I was not going to cause a problem or accident, but I could not flatly state what was going to happen in 10 hours if I moved the rods. After 6 years on my first in fleet real reactor I could tell you where the rods would be within a tenth of an inch 120 hours later. This is why Naval operators get jobs. They learn to become one with their reactor. This is a good thing we want people that understand what they are doing.
What the recruiters don't tell you, is that your course work will only be accepted for credit by colleges that are not ABET-accredited. The two years of nuke school can count as nearly all of an associate's degree in nuclear engineering technology, but almost none in nuclear engineering. I had to start from scratch when I got my degree (in Mechanical Engineering) - I didn't even get PE credit! But on the flip side, because I had a working knowledge of thermo/mechanical/electrical systems as a field tech, I found that my engineering courses were much more comprehensible. I was hungry for the detailed theory at that point, and didn't mind if the particular practice problems were contrived.
There are several lessons learned there but in reality it is really a case for how to do things going forward. I seriously doubt those mistakes will happen again.
I felt that my calculus training was subpar to my high school education. At the same time theory on neutron life cycle and other aspects of a reactor are more important. If I can tell you what is going to happen to the reactor in next 100+ hours then I don't need to fully understand the engineering that got us here. The basic core material here get's us close, not close enough to get to mastery.
I learned advanced Physics using Algebra and then supplemented that with Calculus. Nothing that I learned in Algebra based Physics was undone by Calculus only augmented. I was pretty good at Physics when I was 17 and got better when I was 18 understanding Calculus.
These are not mutually exclusive ideas.
The goal isn't designing plants; someone else already did that. It's knowing enough to know why plants were designed the way they were, as well as being able to safely operate, maintain, and fix the thing.
There is some calculus, but calculus really slows things down when you're trying to work through a lot of material.
From what I got from him, its not like many people are clamoring for these jobs, or have the necessary credentials. It seems like anyone who could do them could get a job as a civilian nuclear engineer. The problem with working in nuclear is that...they only put nuclear power plants in fairly bad locations (NIMBY is a big problem), so you are either stuck with a very long commute or are living in a rural area.
Ah, that was the other thing: the industry was very boom and bust. Dad made bank contracting in the late 70s and early 80s, then they stopped making new plants and it was a scramble to find any job at all around 1985-6. He didn't really want me going into it, I think, so I got into computers instead.
I had a math professor that spent 20 years as a navy nuclear operator (enlisted). At the end of his career he had 2 masters from MIT, one in Math and one in Nuclear Engineering. My understanding is that is fairly common for the best and brightest in the program.
Edit: Submarine
At the same time I have been on 6 off 18. Oh those where great days.
Time in the military is not a constant. It completely depends on the situation and patrol you on. I did complete an economics class in 3 hours with bad grades only because I signed up for it before realizing I was going to be on one of those 6 on 6 off events.