It's August 6th, 1945. The first atomic bomb ever dropped hurtles to the ground. Its fuse fails and with a thunk it buries itself in the ground. The Enola Gay flies home, its crew worried they did something wrong.
Now the brass back in Washington have a problem; they just hand delivered an atomic bomb to their desperate enemies, and it might be easy to repair.
I couldn't find any contingencies about it, but I'm also not a professionally trained historian with access to primary sources. I did find plans, which were abandoned, for building a giant concrete containment vessel around the Trinity device in case that failed to completely detonate, so they could save the uranium.
My question is, what, if anything was their plan for this situation?