I spent a summer (intern) working at the Nevada Test Site and visited the Sedan crater when I was there (my supervisor gave me the 'nickel tour' as he called it).

He said that one of the goals of the Sedan test was to test the feasibility of using nuclear weapons to create a replacement for the Panama canal across the lower part of Mexico "in a hurry." I don't know what their conclusion was but I remain skeptical that such a plan had any merit.

I read that in the early 2000's NASA went back over this test as part of an effort to evaluate what the impact of a nuclear weapon would be as an asteroid defense. And caveat the issue of turning one asteroid into a dozen, they concluded that significant delta-V could be added to an asteroid in this way.