Chernobyl is presumably what you're talking about. It was a high pressure steam explosion due a sudden introduction of energy into the system, which of course

Chernobyl is presumably what you're talking about. It was a high pressure steam explosion due a sudden introduction of energy into the system, which of course would cause an explosion and contaminate a wide area [0]. > The engineering and physics is well understood. as are the safety issues which is why there what research there is for a modern nuclear reactor design would not repeat those mistakes (e.g. molten-salt). Whether the region around Chernobyl is uninhabitable is debatable, given that animals have returned to it in abundance. [0] https://en.wikipedia.org/wiki/RBMK https://en.wikipedia.org/wiki/RBMK