1946 ... Nuke the Poles!
'Operation Plowshare' was the Atomic Energy Commissions attempt to find 'peaceful' uses for nuclear weapons technology. Between 1961 and 1973, twenty-seven nuclear detonations were conducted to test the feasibility of everything from creating harbors to extracting natural gas from rock. Some ideas seemed to work, others didn't. One problem persisted. Everything was wildly radioactive. There were dim promises of special designs for extremely 'clean' atomic explosives whose residual radioactivity would have been lessened. These 'kinder-gentler' bombs never came to be and the project fizzled out under the weight of it's own absurdity.
Here is Edward Teller, one of the most notorious 'Strangelovian' characters, explaining it all to us in a recently de-classified film.