then give us better tools! :) Most of the sims require (at least?) registration with the IAEA: https://www.iaea.org/topics/nuclear-power-reactors/nuclear-r... (I want that Micro-Physics Nuclear Reactor Simulator)

Then there's this https://dalton-nrs.manchester.ac.uk/ but it's down for "maintenance" (a web site - can you imagine?!)

I found this interesting https://www.youtube.com/watch?v=59hVaIjxMIM but people say it does no longer work on recent Windows version. Also I don't like to install random binaries from Mega or similar.

In the end a realistic reactor simulation would probably to complicated for the layman, anyway.

try Nucleares (on Steam), it's a heavily gamified one but does cover various important aspects, including Xenon poisoning. You can find some play videos on YouTube.