A Nuclear Accident in The Third Reich

An article kindly supplied by Nick Brazil, author, film maker and photographer.

The world's first nuclear accident

Most people would be very surprised to learn that the world’s first nuclear accident did not occur in Britain or America but in the heart of Hitler’s Germany.  In the summer of 1942, a team of German nuclear scientists led by Werner Heisenberg had developed an experimental nuclear reactor called L IV in their Leipzig laboratory. As early as 1938, this team under Heisenberg had been working towards creating a nuclear bomb. L IV was the latest stage of this project.

Werner Heisenberg and Niels Bohr

Born in the Bavarian city of Würzburg in 1901, Heisenberg was probably Germany’s most brilliant physicist. He showed early promise in this field when, aged only 24, he published a groundbreaking paper on quantum mechanics. This was the first of many achievements in a life that would be devoted to physics. Not least of his early achievements was to be awarded The Nobel Peace Prize in 1932 for his work on quantum mechanics.

However, he did not spend all his time cloistered away in laboratories. During the turbulent period following Germany’s defeat in World War One, he joined the Freikorps. Made up of a mixture of former soldiers, mercenaries and political idealists, this was a paramilitary group closely aligned with the Weimar Republic. Heisenberg’s motivation for joining was to bring down The Bavarian Soviet Republic in 1918 -19.

In 1922, he met the Danish nuclear physicist Niels Bohr which proved to be a watershed event that would shape the rest of his life. By the mid to late 1930s, Heisenberg was pre-eminent in the field of nuclear physics. He may not have known it then, but Hitler’s new Nazi regime would soon play an important part in his life.

Werner Heisenberg

SS investigation

Curiously, many leading members of the Nazi Party did not cherish Germany’s brilliant scientists like Heisenberg. In fact, they seemed to regard them as secret enemies of the Reich. This led to a personal attack  on Heisenberg in the SS newspaper “Black Corps” which called him a “White Jew” who should “disappear”.

However, he survived this and a subsequent SS investigation, probably because enough influential Nazis appreciated his value to the Reich. At the outbreak of the Second World War, Heisenberg was a member of the Uranverein, the German nuclear weapons programme. It was during this time and before, that Werner Heisenberg and his colleagues including Robert Dopel developed the experimental nuclear reactor called L-IV

Nazi Nuclear programme
Dismantling the German experimental nuclear pile at Haigerloch, 50 km S.W of Stuttgart, April 1945. Courtesy Brookhaven National laboratory, Emilio Segrè Visual Archives, Goudsmit Collection

The reactor explodes

On 23rd June 1942, a leak of heavy water was discovered in the protective jacket of this Leipzig reactor. During the inspection, air  leaked into the  nuclear pile setting the uranium powder inside alight. This immediately caused a violent conflagration boiling the cooling water in the reactor and blowing it apart. Particles of the uranium heated to a temperature of 1000 degrees centigrade shot up six metres to the ceiling and showering across the laboratory building.

After this explosion, which destroyed the reactor, Heisenberg and his team would continue to work on nuclear reaction right up to the end of the war. He was also involved in the country’s weapons programme in other ways as well.


A ploy to prevent the Nazi's getting nuclear weapons?

In June 1942, he was called to a meeting with Albert Speer, Hitler’s Minister For Armaments to discuss the development of the German A-Bomb. Heisenberg had the unenviable task of telling Speer that limitations of manpower and materials meant a nuclear bomb could not be built before 1945. But in saying this, was Heisenberg simply being practical and “telling truth to power”? Or perhaps this just a desperate ploy to prevent the Nazis from getting nuclear weapons for as long as possible.

There is every indication to show that Heisenberg believed nuclear weapons could be developed. Whether he actually wanted an A-bomb in Nazi hands or he simply wanted to develop nuclear fission for energy is an open question.

But this did not seem to be the case with much of the Nazi hierarchy. Strangely, they did not appear to understand the potency of such a weapon. In 1943 the Uranverein was diverted from work on nuclear weapons to nuclear power which was considered more important to the war effort.

This must have delayed the development of Hitler’s A-Bomb for a crucial period. Had this not happened, Nazi Germany could well have dropped the first A-Bomb in anger rather than the Americans. The effect on the course of World War 2 would have been incalculable.

Capture at the end of the war

At the end of the War, Heisenberg was captured by the Allies. He spent a lengthy period of interrogation by British Intelligence in Farm Hall a “safe house” in Godmanchester, Cambridgeshire. To find out what he and the other German scientists really knew, the British spooks had bugged the building.

Perhaps, unsurprisingly, the recordings revealed that all the scientists  were pleased the Allies had won the War. What Heisenberg said was more revealing:

“We wouldn’t have had the moral courage to recommend to the Government in the spring of 1942 that they should employ 120,000 men just for building the thing up.”

Heisenberg was finally allowed back to Germany where he was reunited with his family. He resumed his career in scientific research and development which he pursued for the rest of his life. This included the establishment of Germany’s first nuclear reactor in 1957.

He died in Munich of kidney failure at the age of 74. 

The Leipzig L-IV explosion was the first nuclear accident in history.

This article is an extract from Nick’s latest book:-

“Before Chernobyl – Nuclear Accidents the World Has Forgotten.”

Planned publication is mid 2021.

About The Author

Nick Brazil is an author, film maker and photographer. He has made eight documentaries and numerous shorter videos for the internet. He has also published three books including “Cheating Death – The Story of a PoW” and “Billy Biscuit – The Colourful Life & Times of Sir William Curtis” which is the story of the man who coined the phrase “The Three Rs”


Nick Brazil self portrait
Nick Brazil

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