Could you please write a short description on how to use this mod? I checked on the description thread of the Realistic Reactor in the forum but didn't find any manual for the utilities. I'm especially confused on how to use the underground heat pipe, since I thought I should use it like underground pipes or belts (i.e. put one as an end then put another as the other end), or lay it like the common heat pipe and expect it to have properties like an underground network of heat pipe, but I can't put anything on it. Your help is much appreciated

there's a technology to unlock them
the underground heat pipe basically averages the temperature of all underground heat pipes every tick which is very efficient at transmitting heat. they can be anywhere you want, even on different surfaces.
the heat switch can be controlled like an electricity switch via circuit network
radiation suit reduces radiation damage
decontamination foam can remove radiation or extinguish fires