HipShot would be the one to ask if that is a doable attack target. I'm thinking probably NOT..... given the levels of 24/7 security and authority to shoot without warning beyond posted signs. I know that it's been done on nuke bases overseas in the 1980's. It usually only takes one protester completely riddled by a belt fed M60 machinegun to calm the crowd down. In the post 911 era, I think that trigger fingers would be much more nervous and....itchy.
There is no conceivable way for our nukes to be a target of anything other than inbound mirvs. The success of that would be in grave doubt.
Also, if I recall correctly, our nuke plants.