Uranium from World War II reveals how close the Nazis were to an atomic bomb

Despite claims by Nazi leader Werner Heisenberg, a new study reveals the German atomic bomb project was far from completing a working reactor at the end of World War II. The B8 reactor, composed of five concentric circles of uranium cubes, was intended to achieve a self-sustaining fission reaction but had less than half the heavy water and about half the needed uranium.

The reactor also had significantly fewer cubes than the 1,200 required for successful operation. This study, published in PNAS Nexus, refutes Heisenberg's claim that the reactor was nearly complete and instead suggests it was far from achieving a stable reaction. The heavy water used in the B8 reactor, produced in Norway, was insufficient for the reactor's needs.

The study concludes that Germany could not have built either a heavy water or graphite reactor during World War II.