I am very ignorant on this subject, so i'll be thankful for correcting any wrong assumptions here. As far as i know, both the Little Boy and Fat Man were built in Los Alamos. How would the media, the people and the US Goverment react had one of them accidentally explode during the process? Could such an explosion happen in Hanford Site or any other place of early devolopment or it was just possible during the final assemble?
Thank you all beforehand.
To answer this fully the 'devices' were in fact not fully assembled at any point at Los Alamos, or at Hanford. The Gun-Type (Little Boy) was the one they worried about the most since its operation was both straight forward and the 'easiest' to initiate. As mentioned the bomb wasn't actually "fully" armed until after take off for this very reason. (Parsons and assistant actually crawled into the bomb bay and inserted the 'gun' powder bags just before the run-in) The Implosion-Type (Fat Man and Gadget) bombs actually were actually rather 'safer' when armed as they had a more complex chain to detonation. (Literally more had to 'go-right' in sequence to get an implosion device to work than a gun type)
IIRC the night before the Trinity test they had someone 'babysit' the Gadget because of a lighting storm in the area and this is considered the most likely time to have an 'accidental' yield but as I recall he was really there to pull the wiring harness if the storm got to close as they were afraid either a lightning strike or static build up could cause the harness to go off prematurely. Had this happened it would not have actually 'imploded' the device but still had a high explosive yield.
As noted the main issue wasn't detention but criticality issues which were actually much more likely and, (unfortunately) common.
What about Louis Slotin’s criticality accident?
From accounts he wasn't very 'respectful' of the Demon Core and deviated from procedure in his handling of radioactive materials quite often. The process of "Tickling the Dragon" had initially been planned to use a 'remote' mechanical system but the scientists directly working with the core couldn't get it to work constantly so they came up with the 'manual' process and removing the shims and using a screwdriver blade were NOT in any way safe. (Oddly enough it was the compartmentalization that was an issue since the scientist themselves were less 'mechanically inclined' shall we say and were not allowed to seek help in the design and building of the mechanical system. The original device was stored in a closet at the lab where the initial work had been done and after the work had moved to Los Alamos a janitor/custodian/building-systems-worker found the machine and asked what he should do with it. Told it didn't "work" so throw it out he instead demonstrated several obvious flaws and issues and proccded to "fix" most of them in the afternoon and demonstrated it worked. Shorty afterwards, (after this second accidental death) it was shipped to Los Alamos and it and similar machines were used to test future cores)
So, the answer is no you can't get an actual 'detonation' event at any of the places where the parts were assembled and/or tested but you can get accidents that can kill or seriously injure people, which unfortunately happened far too often anyway.
The men and women working on the Manhattan Project were very intelligent and aware of the 'theory' of what they were doing but often were less aware of the actual practical dangers. Such disconnects were quite common during the early years of atomic development and often happened even with well trained and knowledgeable people doing arguably very obviously stupid things, (the SL1 incident comes to mind) because of a moment carelessness.
Randy