Ten days after the disaster a further risk immeasurably greater than the initial explosions was identified. Initially firefighters had unsucessfully used water to try to extinguish the flames from the reactor. This contaminated water had pooled beneath the reactor core which, having had a combination of sand, clay and boron dropped on it in an attempt to smother the flames, had turned into a lava like substance. This lava was slowly burning through the foor of the reactor, and had it reached the water below would have set off a massive thermal explosion that would have had devastating consquences across most of Europe.Three men -- Valeri Bezpalov, Alexie Ananenko, and Boris Baranov -- volunteered to avert the crisis and paid the ultimate price for doing so.
via /r/TIL
