I built a fluid reactor in survival! -It sank into the swamp.
I built another fluid reactor! -It fell over, burned down, THEN sank into the swamp.
BUT THE THIRD ONE STAYED UP!
Oh, and their explosions aren't so bad.
I built a fluid reactor in survival. It was a BEAR to get all the lead, and I immediately tried to maximize its capabilities. I got it to 608Hu/t, removing 600Hu/t, and it might take an hour to eventually overheat. Well, I got distracted and left it running for something like 3 hours... the core exploded. Fun fact: The liquid shell remained!
So I rebuilt the nuclear core from a side reactor I had. I had to re-create all of the cooling components, but before too long I had a fluid reactor running again.
Over time, I made some iridium and got my reactor all the way to 1350Hu/t, with 1400 Hu/t cooling. Yay! no more overheat problems! As long as I had enough room for the resultant EU, I was fine!
So then I left it on for 3-4 hours with nothing using EU. No heat was converted, no heat was removed, heat built up and it exploded, taking my 4 iridium reflectors with it.
But the liquid shell remained! again!
I will eventually make another nuclear core, and will make more iridium reflectors over time... but for now the sheer amount of production disheartens me. It was fun to make such an accomplishment!
The moral of the story: Make SOME kind of check for reactor shutdown. Levers are cheap but not recommended for reactor control.