I brought up this question during the current TL about what if Germany had the bomb at D-day, but after searching it, it seems a separate topic not covered before (I may be wrong).
Background: During the Manhattan project scientist were acutely aware that neutron got absorbed into surrounding materials and of the deadly potential of radiation (they lost scientists to it). Leo Szilard is usually credited with the "Salted Bomb" concept in which a good absorber that produces really nasty isotopes is placed around a nuclear weapon. When it goes off, the fallout is MUCH more troublesome than after a regular weapon. I am postulating that everyone new this and Leo Szilard just publicized the potential to create debate about the devastating potential of nuclear weapons (the underlying bit seems logical, but I have no reference. The other part is the stated reason).
Suppose that something goes wrong and the first field test results in a fizzle (incomplete detonation) and less than wanted effect. The bombs needs to go to have role in the war and it is decided to upgrade the disappointing weapon with a nice Cobalt casing. When it is then deployed it works beautifully. What happens next?
Consequences for Japan? For nuclear weapons? For the US prestige as they (by mistake) used excessive brutality?