I got a laugh out of this one (in a "OMG, you have got to be kidding" kind of way). According to an organisation called the Project on Government Oversight, there have been a few incidents at the Pantex facility, near Amarillo, Texas where nuclear weapons are disassembled. One of these incidents was called a "near-miss event" and could have meant a massive nuclear disaster:
Pantex has had serious safety problems spanning back at least several years. For example, in 2004, while a W56 warhead – which, at 1200 kilotons (or 100 times the yield of a Hiroshima bomb), is one of the largest missile-launched warheads in our stockpile – was being disassembled, a crack was discovered in the high explosive (HE). Technicians used the equivalent of duct tape to hold the cracked high explosive together. The next year, Pantex paid a $124,000 fine for safety violations related to the HE cracking incident.
Now we have learned that in March 2005, there was a “near-miss?? event while disassembling another W56 warhead. Apparently the production technicians were using a faulty tool, putting too much pressure on the warhead. On November 29, 2006, Pantex was only fined $110,000 – 18 months after the near-miss incident. What was not made public at the time the fine was levied, however, is that according to safety experts knowledgeable about this event, it could actually have resulted in the detonation of the warhead. This incident was particularly dangerous because the W56 warhead was deployed in 1965, pre-dating the three basic enhanced safety features which reduce the possibility of an accidental detonation that are now required on more modern weapons. There are still several older warheads slated for dismantlement that do not include these enhanced features.
The W56 warhead is 100 times more powerful than the bomb dropped on Hiroshima and could have put a serious dent in Texas. From the looks of it, the facility may be underground but look how close it is to a populated area: