From watts to warheads: Secretary of energy oversees big science research and the US nuclear arsenal

The U.S. Department of Energy was created in 1977 by merging two agencies with different missions: the Atomic Energy Commission, which developed, tested and maintained the nation's nuclear weapons, and the Energy Research and Development Administration, a collection of domestic energy research programs.

Today the department describes itself, with what some might call understatement, as "one of the