In a sprawling plant near Amarillo, Texas, rows of workers perform by hand one of the most dangerous jobs in American industry. Contract workers at the U.S. Department of Energy's Pantex facility gingerly remove the plutonium cores from retired nuclear warheads.

Although many safety rules are in place, a slip of the hand could mean disaster.

In Energy Department facilities around the country, there are 54 metric tons of surplus plutonium. Pantex, the plant near Amarillo, holds so much plutonium that it has exceeded the 20,000 cores, called "pits," regulations allow it to hold in its temporary storage facility. There are enough cores there to cause thousands of megatons of nuclear explosions. More are added each day.