Let us assume that before the nuclear bomb was ever invented in the United States, us Americans lived in a state of minarchy, anarcho-capitalism, or whatever.
So when WW2 came about, from the beginning we as a nation decided to stay out of the conflict. All of the intellectuals/scientists in the warring nations then proceeded to flee to the US to escape the madness and persecution, the "brain drain" as it is called. As a super power in a world of mad warring nations, we then decide to establish means
for defense only. The scientists living in the country, would have no reason whatsoever to create an atom bomb. Their time and limited resources would be spent on something more productive instead of the insanely destructive atom bomb. The Manhattan project simply would not have been able to come about in a libertarian minded country, the funds would not be allotted to them and the scientists would not agree to work together to create it.
My point by saying all of this is:
If it were not for big government, if we had been living in a libertarian society all along, the atom bomb would not have been invented.
But since we unfortunately live in a statist world, and nukes do exist.... In the transition to a more libertarian society, most if not all of our nuclear arsenal would be destroyed.
The policy for individual or corporate ownership of nukes might have to be what this guy said:
Nuclear weapons present a public danger if not properly contained, and no private citizen has the ability to be able to store them.
So basically, it might be necessary for a libertarian minded government to use its power to protect people against the after-effects of a statist government (the invention of nuclear weaponry).