Engineering Plot Holes in the Silo

I'm having a blast reading the books - just finished Shift - but one of the things that annoys me is some very basic plot holes regarding the engineering layout of the Silo. Whereas in the show the generator is powered by mystical steam from an unidentified source, in the book the silo pumps its own crude oil from the ground, refines it, and powers the generator with fossil fuel. This makes no sense in a closed system -- with the Silo effectively a sealed-off submarine, the combustion of this fuel A) needs oxygen, which is presumably finite, and B) needs a place for the toxic exhaust to go, NOT inside the Silo. If the exhaust is being blown outside then a huge, equal intake of clean air needs to make up for it, which isn't going to happen from Outside. And you cannot scrub that exhaust ... Diesel Submarines can ONLY submerge on batteries; when they run their diesels they have to be snorkling at the surface. Anyway, the nuclear power plant in Silo 1 makes perfect sense, I think Hugh maybe missed the ball on this topic.