Science literature is often held back by facts, where you can express yourself, like an expository essay since they are held back by facts as well. Plain fiction is all up to the author with nothing holding them back, like an argumentative essay would be since it’s opinionated.
2 goes with the second one (control rods).
3 goes with forth one (mass of unstable fuel)
4 goes with one (shield)
1 goes with third one (moderator)
5 goes with coolant
