Maybe this is a dumb question. But I'm going on my annual wikipedia dive on nuclear disasters. If they built all of these like 500m below the surface and covered in heavy rocks or concrete/steel wouldn't most of the effects of a total melt down be contained by the ground? It seems like the worst part of a subterainian melt down vs one on the surface is there is probably a mini earth quake in the area. But in my mind it seems most of the fallout and radiation would be contained, you only have to worry about ejected materials and chuncks i suppose?/ And as long as your reactor isnt near any fault lines i dont see any real danger. Also after a melt down it seems itwould be much easier to fix the problem if its in a giant hole in the ground vs sitting in the middle of a Djiboutin village. IDK, educate me internet.