Luckily they mostly worked well enough that we didn't have to repair them-- or use fire extinguishers on them.
"What's that, ensign? You want a checkout on this here control rod drive mechanism? Well, sure, why'n'cha sitcherself down right over there and draw me a cross-section of the CRDM while I get a cup of coffee. When I get back you can describe what happens when the Reactor Operator applies latch voltage, and then show how the current flows and which direction the motor turns when he shims out. Oh, and what happens to the system if this fuse right here blows?"
Here's an "unclassified" system which I'm sure is just a coincidental resemblance using similar technological design principles:
http://jolisfukyu.tokai-sc.jaea.go.jp/fukyu/tayu/ACT01E/02/0202.htm
Ever pop the hood of a fire control computer? You know, the older ones that had to be greased weekly?
Hey, I still have my graduation certificate from Mk 113 Mod 9 Fire Control System school-- you know, from back when submariners had to be real steely-eyed killers of the deep twiddling analog dials, not just a bunch of sissified electronic dot-stackers...
Although I sincerely hope that both of those systems will never again be inflicted on unsuspecting young submariners.
The USS BOWFIN Submarine Museum has earlier versions of these FCSs from older nuclear boats. When I try to explain to my daughter how they work, she looks at me like I'm an animatronic dinosaur with vocal cords.
