Werner Heisenberg, in a meeting that includes senior Nazi officials, declares: As soon as such a machine [reactor] is in operation, the question of how to obtain explosive material, according to an idea of von Weizsäcker takes a new turn. In the transmutation of the uranium in the machine, a new substance comes into existence, element 94, which is very probably—just like 92U235—an explosive of equally unimaginable force. This substance is much easier to obtain from uranium than 92U235, however, since it can be separated from uranium by chemical means.
