You are indeed correct and it was Sweeny who I talked with. Somewhere I have an autographed photo I paid $5 for of him.
An H-Bomb was dropped over the Carolinas as well as three off the coast of Spain. As the unoffical story goes, one of the bombs was one fail safe device away from actually dentonating and when this was found out, the failsafe mechanisms were changed.
The explosions that resulted were from the chemical explosive lenses that are used to trigger the bomb, going off. In order to have an actual ignition, the Bomb needs a source of neutrons at the moment of ignition without which you just have a chemical explosion. -Dick