The details on Castle Bravo and why the yield was unexpectedly high is an interesting story. If I remember correctly, there was some stuff they thought wouldn't be involved in the reaction, but due to the nuclear reaction of the explosion (nuclear synthesis?), it got converted to "fuel" and gave them more bang than they expected.
was a big, big Russian nuke.
The US almost nuked North Carolina
There's some amazing stories involving nuclear power and bombs.