Workers examine a B53 nuclear bomb at the B&W Pantex nuclear weapons storage facility outside Amarillo, Texas, in this handout photograph taken and released on October 25, 2011. The United States dismantled the oldest nuclear bomb in its Cold War arsenal -- and one of the most powerful it ever built -- on Tuesday as part of President Barack Obama's nuclear security policy. Built at the height of the Cold War in 1962, the bomb was designed to be dropped onto a target by a massive B-52 Stratofortress strategic bomber.