Why the moaning about nuclear power plant cost if refineries sit at a similar cost?
Refineries return that money faster.
Human lifespan is short. So things that affect one human lifespan quickly are scarier. Radiation scares people because it can kill them fast. Effects from oil and gas tend to take much longer.
What kind of things go into a refinery that form that price?
Engineering costs, inspection costs, a lot of stainless steel tanks and tubing, a lot of stainless steel valves/clamps/misc attachments, a lot of stainless steel welding that needs to be certified, redundant failsafes, various safety devices/monitoring systems, etc. I'm sure some bribes are buried/hidden in these costs as well, such as if you allow this oil refinery we'll use your construction company and you can over charge us so any payoff is legal.