“It’s still claimed to be unlivable after 60 years, but I would take that with a grain of salt if you consider Hiroshima and Nagasaki with the caveat the both Japanese sites were actively “decontaminated” while the Bikini Atoll was not.”
That atoll blast(s) actually hit the ground, I think that those may have been hydrogen based, and blew part of the atoll itself away; the Japan blasts were in the air which is “cleaner”.
The Atoll blasts were numerous, and both nuclear and Thermonuclear. Detonating such weapons on the surface, or in some cases below the surface (waterline) are inherently more “dirty” as far as nuclear fallout is concerned, so your point is crucial.
However, no “cleanup” that would be useful with current knowledge was ever undertaken as far as I can tell, but I may be mistaken with that premise. Even more to the point, such cleanup may not have even been feasible considering the difference in “terrain” between my two examples, so that point is also crucial concerning a valid comparison.
I suppose it would have been a better point to consider if the Marshall Islands would be better off if a concerted effort would have been made to decontaminate the affected sites by our country over the last 6 decades considering we were the ones who contaminated it in the first place, along with the question of would it have been viable in the first place.
So many variables...