When we talk about nuclear accidents we often think of Chernobyl or Fukushima, but perhaps not everyone knows that the first accident of this type in history occurred in the Nazi Germany The 23 June of 1942. That day in a basement of theUniversity of Leipzig a group of physicists led by Werner Heisenberg He was carrying out studies on uranium but, due to an incorrect experimental setup, a sudden hydrogen production occurred inside the L-IV reactor. The flames produced not only destroyed the reactor but caused a large fire in the building which, within two days, became charcoal And radioactive.
The setup of the experiment
The goal of Heisenberg and Professor Robert Döpel it was to make a reactor capable of produce neutronsso as to start a nuclear fission reaction controlled. After various experimental attempts and sett-ips, they made the model L-IV. From a technical point of view, these were two aluminum semi -sisferes held together by 22 Rivets And, of the two parts, the lower one was immersed for three quarters in a small water tank installed specifically in the laboratory floor. This, ideally, would have prevented the merger of aluminum in the event that criticality had been reached.
On the internal surface of the aluminum sphere from 1.6 meters there was a level of metal uranium, kept in place by another aluminum sphere. Inside this second sphere there was a heavy water level And, again, one third smaller sphere aluminum containing another layer of uranium. Finally, at the center of everything, the fourth and last aluminum sphere containing heavy water. Transversely to these spheres was present a fireplace that came straight in the central sphere.
The idea behind the experiment was to drop inside the fireplace (and therefore in the heart of the central sphere) a mix of powders of radio and beryllium To start the production of neutron. These would have been slowed down by heavy water and would then hit the first level of uranium. The neutrons produced by this layer of uranium would in turn have been slowed down by the subsequent level of heavy water and finally they would have hit the Second and last layer of metal uranium. He too would have produced neutrons, and the objective of the experiment was really measured how many were produced.
The nuclear accident caused by the Nazis
That fateful morning of the June 23, 1942 Dr. Döpel noted that the tub installed at the base of the laboratory began to rise bubbles. He then approached a match to one of these and immediately felt a small burst: it was a loss of hydrogen.
Döpel He immediately went to call Heisenberg and, shortly after his arrival, from the sphere they started to go out flames And melted uranium, who began to spread throughout the laboratory. The pressure inside the sphere was going up and then the two scientists immediately abandoned the room. In a short time the L-IV reactor explodedmaking a fire burst into the building. According to the information at our disposal there were no victims but the entire building burned in two days – despite the efforts of the firefighters.
We do not know what went wrong from a technical point of view to today, even if it was probably one loss In one of the spheres that caused the contact Between air, water And uranium, causing the spontaneous combustion of the latter and the liberation of large quantities of hydrogen – which, as is well known, is highly flammable. The fact is that the news immediately went around the academic world, deceiving himself day by day: in the USA it was in fact thought that this disaster had killed an entire team of German scientists.
