300 seconds will produce a relatively quick death, which is better than many alternatives. 

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....