When it comes to nuclear weapons, one doesn't want to accept any risk of accidental detonation - it's bad enough if someone pushes the button on purpose - or someone making off with nuclear materials (of any kind). However, if what I learned in graduate school is true, then we have to live with some risk, even with nukes; now that's just a bit unnerving.
Of course, we have some pretty smart people (a whole lot of them in fact) working in our nuclear weapons laboratories, making sure that the nuclear weapons they design are reliable (read "They won't blow unless we want them to."). Then, there is the military (the Air Force in this case) that is responsible for ensuring the safety of these weapons out in the real world. That's where things get a little sketchy.
We learned over the course of 2008 about events in the prior year that raise serious questions about the people directly responsible for the safety and security of our nations nuclear weapons.
The most serious incident involved personnel at Minot Air Force Base "mistakenly" loading nuclear tipped Cruise missiles onto a B-52 bomber, which was flown to Barksdale Air Force Base. The nuclear weapons went unnoticed and unprotected from the time they were removed from the bunker to well after the bomber landed at Barksdale (a mere 36 hours); only when the weapons were being unloaded did anyone notice that something was amiss! Reading the details of how many things went wrong - all of them related to human error - is enough to make you dizzy.
Of course, there was some sort of "inquisition", but even after all that Minot's 5th Bomb Wing failed the initial nuclear surety inspection (NSI) required for re certification to handle nuclear weapons. It finally passed an NSI three months later at the end of March 2008. Of course the Air Force came up a laundry list of things to do ensure nuclear weapons safety. One interesting change is that they no longer allow nuclear armed and nonnuclear armed weapons in the same storage facility. And, all nonnuclear weapons have to have placards stating that they are not armed with nukes. I'm feeling much safer now. Aren't you?
By the way; did I mention that the infamous 5th Bomb Wing again FAILED the mother of all NSI's in May 2008??? You can read all about it in the Air Force Times that referred to the "Litany of Failure". The 5th finally received a "passing grade" in August. Did I also mention that these NSI's were scheduled so that everyone knew what was coming? Nuclear bases have since moved to "no notice inspections"; now there is a novel concept.
Of course if they can't pass scheduled inspections... Well, you get the idea. So where is all this leading? We have been living with nuclear weapons since 1945 (over 63 years) and although there have been many incidents and accidents since then, it is only a matter of time before one of those accidents causes the detonation of a nuclear weapon. So wouldn't it be prudent to do all we can to continue dismantling these weapons of mass destruction before they dismantle us? After all, no matter how well we design them, sooner or later something will fail. And as for the human beings that tend to them; well, nobody is perfect.
P.S. - I almost forgot to mention the Air Force Times reported that in the failed May NSI, "one security forces airman was found using his cell phone to play video games while on guard duty in a restricted zone". Better living through modern technology.