Dimitri’s Reviews > The First War of Physics: The Secret History of the Atom Bomb, 1939-1949 > Status Update

The energy released in a slow neutron reaction would heat up the uranium, possibly melting or even evaporating it long before it could explode. As the uranium heated up, more and more neutrons would escape the surface and eventually the chain reaction would grind to a halt.

What if?... A fast-neutron chain reaction in pure U-235. Insofar as the atomic bomb ever had a secret, Frish had just found it.