Figure 1.--.

The German reserarch team concluded at an early point that the plutonium 239 option was preferable because the critical mass was smaller and the bomb itself would be easier to construct. The German scientists failed to perfect a graphite-moderated reactor for plutonium production. They thus explored a heavy water based reactor. This would be useful for bomb research and eventually breed the plutonium for a fission weapon. Heavy water is also called deterium oxide. It is an isotope of hydrogen which has a neuton in the nucleus. Thus it has double the atomic weight of ordiary hydrogen. This characteristic slows down neutrons in radoactive elements. In the case of uranium 235, it facilitates a chain reaction of exploding atoms that produces plutonium, another fissionable element. Heavy water itself was not a component of the atom bomb, but it was essential in experiments associated in the manufacture of a bomb. Enormous quantities of electrical powerwere needed to produce heavy water in any quantity. This could not be done in the Reich because the diversion of electical power would have disrupted war industries. The United States had the electricalm power generating capacity to do this. Germany did not. There was only one place in Europe capable pf producing large quatities of heavy water--Telemark, Norway. And the NAZIs had occupied Norway (April 1940). The Norwegians had constructed the Vemork hydroelectricity power plant outside Rjukan in Tinn. The 60-MW Vemork plant was named after a waterfall, but is often referred to as Telemark which is the name of the county. The plant was constructed for Norsk Hydro (1911). The primary purpose was to produce hydrogen needed to manufacture fertilizer. Norsk Hydro built the first commercial plant at Vemork specifically to produce heavy water (1934). It had the capacity to produce of 12 tons of heavy water annually. Just before the German invasion, Deuxième Bureau (French intelligence) successfully removed 185 kilograms of heavy water from the plant. Many Norwegian scientists fled Norway when the NAZIs occupied the country. Professor Leif Tronstad, designer and construction supervisor of the Vemork plant, remained with his family in Norway. He managed to inform the British of German plans to increase production of heavy water. A double agent informed Tronstad that the Germans had learned of his illegal transmissions and he had to flee to Britain (September 1942). British and Resistance attacks prevented the Germans from getting much of the plant's production back to the Reich. Norwegian resistance damaged the plsnt. The attacks were code named Freshman, Grouse and Gunnerside. The Gunnerside attack argeted the fuel cells and destroyed the plant woks (February 1943). The Germans attempted to repair the damage and had the plant opersational agin (August 1943). The resistance kept the Allies informed of German activities. The Americans bombed the plant (November 16, 1943). The plant was so severly damaged that Göring, responsible for bomb projrct, ordered the heavy water production effort moved back to the Reich. About 14 tons of heavy water survived the bombing. The Germans attempted to transpoort the drums of heavy water protected by SS guards by rail and ferry (February 20, 1944). The resistance blue up the ferry. The Germans were only able to salvage three drums. By this time the war siutation had been significantly changed. German had suffered enormous defeats in the East and Mediterraean. the Allies were achieving air superiority over Germany. The Germans did not haver capacity to produce heavy water in 1940 and had even less capacity in 1944. And without the heavy water, the German researchers had not been able to pursue planned operations.

Plutonium Option

The German reserarch team concluded at an early point that the plutonium 239 option was preferable because the critical mass was smaller and the bomb itself would be easier to construct. This meant that it would be necessary to produce plutonium which does not exist naturally.

Profuction Methods

The German scientists failed to perfect a graphite-moderated reactor for plutonium production. They thus explored a heavy water based reactor. This would be useful for bomb research and eventually breed the plutonium for a fission weapon.

Heavy Water

Heavy water is also called deterium oxide. It is an isotope of hydrogen which has an extra neuton in the nucleus. Thus it has double the atomic weight of ordiary hydrogen. This characteristic slows down neutrons in radoactive elements. In the case of uranium 235, it facilitates a chain reaction of exploding atoms that produces plutonium, another fissionable element. Heavy water itself was not a component of the atom bomb, but it was essential in experiments associated in the manufacture of a bomb. Enormous quantities of electrical power were needed to produce heavy water in any quantity. This could not be done in the Reich because the diversion of electical power would have disrupted critical war industries. The United States had the electricalm power generating capacity to do this. Germany did not. The industrial production of heavy water requires a technical infrastructure. The required facilities are similar to those required for ammonia production, alcohol distillation, and other standard industrial processes.

Norway (1940-44)

There was only one place in Europe capable pf producing large quatities of heavy water--Telemark, Norway. And the NAZIs had occupied Norway (April 1940). The Norwegians had constructed the Vemork hydroelectricity power plant outside Rjukan in Tinn. The 60-MW Vemork plant was named after a waterfall, but is often referred to as Telemark which is the name of the county. The plant was constructed for Norsk Hydro (1911). The primary purpose was to produce hydrogen needed to manufacture fertilizer. Norsk Hydro built the first commercial plant at Vemork specifically to produce heavy water (1934). It had the capacity to produce of 12 tons of heavy water annually. Just before the German invasion, Deuxième Bureau (French intelligence) successfully removed 185 kilograms of heavy water from the plant. Norway was still neutral at the time. The plant's managing director, Aubert, agreed to loan the heavy water to the French for the duration of the war. The French secretly transported it first to Oslo and then on to Perth, Scotland and finally to France. Of course the French could not conceive of Frebch capitulation to the Germans. Many Norwegian scientists fled Norway when the NAZIs occupied the country. Professor Leif Tronstad, designer and construction supervisor of the Vemork plant, remained with his family in Norway. He managed to inform the British of German plans to increase production of heavy water. A double agent informed Tronstad that the Germans had learned of his illegal transmissions and he had to flee to Britain (September 1942). RAF reconisance flighs provided additional information. (A HBC reader is trying to acertain if the RAF used thecAmerican P-51 Mustangs fitted with extra fuel tanks (150 gallon) in the ammo/gun bays during 1942-43. [Bybee]) British and Resistance attacks prevented the Germans from getting much of the plant's production back to the Reich. Norwegian resistance damaged the plant. The attacks were code named Freshman, Grouse and Gunnerside. The Gunnerside attack targeted the fuel cells and destroyed the plant woks (February 1943). The Germans attempted to repair the damage and had the plant opersational agin (August 1943). The resistance kept the Allies informed of German activities. The Americans bombed the plant (November 16, 1943). The plant was so severly damaged that Göring, responsible for the bomb project, ordered the heavy water production effort moved back to the Reich. About 14 tons of heavy water survived the bombing. The Germans attempted to transpoort the drums of heavy water protected by SS guards by rail and ferry (February 20, 1944). The resistance blue up the ferry. The Germans were only able to salvage three drums. [Drummond] This ended German efforts to get Norwegian heavy water to the Reich.

War Situation (1944)

The inability to obtain the Norwegian heavy water dusrupted the German research effort. And by the time the final German efforts in Norway failed, the war siutation had been significantly changed. Germant\y had suffered enormous defeats in the East and Mediterraean. Andcthe Allies finally landed in Normandy. The Allies were achieving air superiority over Germany. The Germans did not have capacity to produce heavy water in 1940 and had even less capavity in 1944. And without the heavy water, the German researchers had not been able to pursue the plutonium option..

Sources

Bybee, John. E-mail message, April 5, 2011.

Drummond, John D. But Tor These Men.

Created: 1:59 AM 4/6/2011
Last updated: 1:59 AM 4/6/2011