After just 30 seconds of exposure, dizziness and fatigue will find you a week later. Two minutes of exposure and your cells will soon begin to hemorrhage; four minutes: vomiting, diarrhea, and fever. 300 seconds and you have two days to live.
By the fall of 1986, the emergency crews fighting to contain the nuclear disaster at Chernobyl made it into a steam corridor beneath failed reactor Number 4. Inside this chamber they found black lava that had oozed straight from the core. The most famous formation was a solid flow that their radiation sensors firmly told them not to approach. With cameras pushed in from around a corner, the workers dubbed the dimly lit mass "the Elephant's Foot." According to readings taken at the time, the still hot portion of molten core put out enough radiation to give a lethal dose in 300 seconds.
The Elephant's Foot could be the most dangerous piece of waste in the world.
Hot Zone
During a routine test on April 26, 1986, reactor Number 4 at the Chernobyl Nuclear Power Plant experienced a power surge that triggered an emergency shutdown. It did not work. The attempt to manage the surge in power and the alarming increase in the core's temperature caused an even larger power surge. Control rods that are used to manage core temperature were inserted too late. Their insertion into the hot core caused the rods themselves to crack and fracture, locking them in place. Heat and power output continued to rise until the water that was used to cool the entire reactor vaporized, generating massive amounts of pressure. The first explosion from the steam inside the reactor was enough to send the 4-million-pound lid of the reactor assembly through the roof of the building. Now catastrophically damaged, the remaining cooling water from broken channels seeped into the reactor as well, turning directly into steam as it touched the increasingly hot nuclear fuel rods. A second, even more massive explosion followed shortly after the first, belching broken core material into the air, spreading fire and radioactive detritus.
With a glowing heart no longer shielded by tons of steel and concrete, the core could no longer be cooled. It began to melt.
When we say that a nuclear reactor "melts down," it's not simply illustrative language. The radioactive materials used as fuel get hotter and hotter, due to their unstinting emission of high-energy particles, until they literally melt, turning into something like lava. At Chernobyl, the loss of coolant caused a meltdown of the fuel, some of which was scattered into the atmosphere. Much of it however, flowed into the bottom of the reactor vessel and eventually melted through it. Oozing through pipes and eating through concrete, the radioactive lava flow from reactor Number 4 eventually cooled enough to solidfy. The result was a collection of stalactites and stalagmites, steam valves clogged with hardened lava, and the large black mass that would later be dubbed the Elephant's Foot.
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