The 80th anniversary of the atomic bombing of Hiroshima and Nagasaki is this week. It was the only time nuclear warheads were used during war. Here’s a look at the history and current U.S. stockpile.

The Hiroshima atomic bomb, with an explosive yield of 15 kilotons, would be considered a low-yield nuclear weapon by today’s standards. The largest nuclear weapon in the US arsenal has a yield of 1.2 ...

Add Yahoo as a preferred source to see more of our stories on Google. A subsurface atomic test near Yucca Flats, Nev., in March 1955. (U.S. Atomic Energy Commission via AP) (U.S. Atomic Energy ...