??? if youve got anything remotely like a meltdown, the pressure of the water goes up and will burst a seam eventually. The water will boil away before things get chernobyl bad.
Okay, reading through part of the book I have come to the following conclusions:
Professor Esau, who effectively started the first atomic weapon program, needs to be brought into the program that has been started by the War Office, rather than shunted aside and left outside of it entirely. While the progress he had accomplished was mixed, he had already obtained the overwhelming majority of the uranium compounds that were available through the Economics Ministry, and refused to release them to the other teams.
Force the scientists to work together at the Kaiser Wilhelm Institute, rather than allowing them to stay at their various universities and colleges. Many would come in for maybe a day a week to discuss the program with the others before returning home, producing a very inefficient organization, made even worse considering some of the best equipment for the project was there at the Institute. This POD would have been around the 20th of September in 1939.
Of course, you would also have everyone trying to work on a single team, rather than having a whole host of teams trying to beat the others in results.
Keep Peter Debye as the Director of the Institute. The man's departure created a vacuum between what would become the division of the scientists into the Heisenberg and Diebner factions. Even if he still departs, try and find someone that is not so liable to inflame tensions.
Keep Heisenberg from coming to the conclusion that Graphite is not an effective moderator.
Keep the French from attaining the available Heavy Water from the Norwegian plant shortly before the German Invasion. Send a less effective negotiator possibly.
There were also early proposals for a Heavy Water plant to be built in Germany, can't remember the exact location they were looking at, though I am not sure how realistic it is, let alone the time-frames involved.