That's exactly what you do, but that means some finely pulverised irradiated material probably gets ejected. The notorious example of this was the Sedan nuclear

That's exactly what you do, but that means some finely pulverised irradiated material probably gets ejected. The notorious example of this was the Sedan nuclear excavation test [1] which created a usefully big hole (100m deep, 390m diameter) by removing some 11 million tons of soil, but "the radioactive fallout from the test contaminated more US residents than any other nuclear test." Much of the fallout was due to the fraction of the yield that was from fission, and WP notes that "had this test been conducted after 1965 when improvements in device design were realized, achieving a 100-fold reduction in radiation release is considered feasible". But the public enthusiasm for the program was naturally impaired. [1] https://en.wikipedia.org/wiki/Sedan_(nuclear_test) https://en.wikipedia.org/wiki/Sedan_(nuclear_test)