are those \"web\" structures you see in the above screenshot.
It acts as a redundancy against hull breaches, so if power gets split, it is automatically re-routed.
I also have a \"coil\" reactor that\'s a condensed structure of the typical design, just cylindrical instead of oblong.
There are also multiple power \"bricks\" just for stacking in those extra power gen, since after 1mil regen the \"axis\" method no longer applies.
Hope this answered your question.
~TheSol