German nuclear energy project The German nuclear energy project ( German : " Uranprojekt " ; informally known as the Uranverein ; English : " Uranium Society " ) , was an attempted clandestine scientific effort led by Germany to develop and produce atomic weapons during World War II . This program started in April 1939 , just months after the discovery of nuclear fission in January 1939 , but ended only months later , due to the German invasion of Poland , where many notable physicists were drafted into the " Wehrmacht " . However , the second effort began under the administrative auspices of the " Wehrmacht ' s " " Heereswaffenamt " on the day World War II began ( 1 September 1939 ) . The program eventually expanded into three main efforts : the " Uranmaschine " ( nuclear reactor ) , uranium and heavy water production , and uranium isotope separation . Eventually it was assessed that nuclear fission would not contribute significantly to ending the war , and in January 1942 , the " Heereswaffenamt " turned the program over to the Reich Research Council while continuing to fund the program . At this time , the program split up between nine major institutes where the directors dominated the research and set their own objectives . At that time , the number of scientists working on applied nuclear fission began to diminish , with many applying their talents to more pressing war - time demands . The most influential people in the " Uranverein " were Kurt Diebner , Abraham Esau , Walther Gerlach , and Erich Schumann ; Schumann was one of the most powerful and influential physicists in Germany . Diebner , throughout the life of the nuclear energy project , had more control over nuclear fission research than did Walther Bothe , Klaus Clusius , Otto Hahn , Paul Harteck , or Werner Heisenberg . Abraham Esau was appointed as Hermann Göring ' s plenipotentiary for nuclear physics research in December 1942 ; Walther Gerlach succeeded him in December 1943 . Politicization of the German academia under the National Socialist regime had driven many physicists , engineers , and mathematicians out of Germany as early as 1933 . Those of Jewish heritage who did not leave were quickly purged from German institutions , further thinning the ranks of academia . The politicization of the universities , along with the demands for manpower by the German armed forces ( many scientists and technical personnel were conscripted , despite possessing useful skills ) , would eventually all but eliminate a generation of physicists . At the end of the war , the Allied powers competed to obtain surviving components of the nuclear industry ( personnel , facilities , and materiel ) , as they did with the V - 2 program . Discovery of nuclear fission . In December 1938 , German chemists Otto Hahn and Fritz Strassmann sent a manuscript to the science journal " Naturwissenschaften " ( " Natural Science " ) reporting they had detected the element barium after bombarding uranium with neutrons ; simultaneously , they communicated these results to Lise Meitner , who had fled in July to the Netherlands and then to Sweden . Meitner , and her nephew Otto Robert Frisch , correctly interpreted these results as being nuclear fission . Frisch confirmed this experimentally on 13 January 1939 . First " Uranverein " . Paul Harteck was director of the physical chemistry department at the University of Hamburg and an advisor to the " Heereswaffenamt " ( HWA , Army Ordnance Office ) . On 24 April 1939 , along with his teaching assistant Wilhelm Groth , Harteck made contact with the " Reichskriegsministerium " ( RKM , Reich Ministry of War ) to alert them to the potential of military applications of nuclear chain reactions . Two days earlier , on 22 April 1939 , after hearing a colloquium paper by Wilhelm Hanle on the use of uranium fission in a " Uranmaschine " ( uranium machine , i . e . , nuclear reactor ) , Georg Joos , along with Hanle , notified Wilhelm Dames , at the " Reichserziehungsministerium " ( REM , Reich Ministry of Education ) , of potential military applications of nuclear energy . The communication was given to Abraham Esau , head of the physics section of the " Reichsforschungsrat " ( RFR , Reich Research Council ) at the REM . On 29 April , a group , organized by Esau , met at the REM to discuss the potential of a sustained nuclear chain reaction . The group included the physicists Walther Bothe , Robert Döpel , Hans Geiger , Wolfgang Gentner ( probably sent by Walther Bothe ) , Wilhelm Hanle , Gerhard Hoffmann , and Georg Joos ; Peter Debye was invited , but he did not attend . After this , informal work began at the Georg - August University of Göttingen by Joos , Hanle , and their colleague Reinhold Mannkopff ; the group of physicists was known informally as the first " Uranverein " ( Uranium Club ) and formally as " Arbeitsgemeinschaft für Kernphysik " . The group ' s work was discontinued in August 1939 , when the three were called to military training . Another notification . The industrial firm " Auergesellschaft " had a substantial amount of " waste " uranium from which it had extracted radium . After reading a June 1939 paper by Siegfried Flügge , on the technical use of nuclear energy from uranium , Nikolaus Riehl , the head of the scientific headquarters at Auergesellschaft , recognized a business opportunity for the company , and in July he went to the HWA ( " Heereswaffenamt " , Army Ordnance Office ) to discuss the production of uranium . The HWA was interested and Riehl committed corporate resources to the task . The HWA eventually provided an order for the production of uranium oxide , which took place in the Auergesellschaft plant in Oranienburg , north of Berlin . Second " Uranverein " . The second " Uranverein " began after the " Heereswaffenamt " ( HWA , Army Ordnance Office ) squeezed out the " Reichsforschungsrat " ( RFR , Reich Research Council ) of the " Reichserziehungsministerium " ( REM , Reich Ministry of Education ) and started the formal German nuclear energy project under military auspices . The second " Uranverein " was formed on 1 September 1939 , the day World War II began , and it had its first meeting on 16 September 1939 . The meeting was organized by Kurt Diebner , advisor to the HWA , and held in Berlin . The invitees included Walther Bothe , Siegfried Flügge , Hans Geiger , Otto Hahn , Paul Harteck , Gerhard Hoffmann , Josef Mattauch , and Georg Stetter . A second meeting was held soon thereafter and included Klaus Clusius , Robert Döpel , Werner Heisenberg , and Carl Friedrich von Weizsäcker . Also at this time , the " Kaiser - Wilhelm Institut für Physik " ( KWIP , Kaiser Wilhelm Institute for Physics , after World War II the Max Planck Institute for Physics ) , in Berlin - Dahlem , was placed under HWA authority , with Diebner as the administrative director , and the military control of the nuclear research commenced . When it was apparent that the nuclear energy project would not make a decisive contribution to ending the war in the near term , control of the KWIP was returned in January 1942 to its umbrella organization , the " Kaiser - Wilhelm Gesellschaft " ( KWG , Kaiser Wilhelm Society , after World War II the Max - Planck Gesellschaft ) , and HWA control of the project was relinquished to the RFR in July 1942 . The nuclear energy project thereafter maintained its " kriegswichtig " ( important for the war ) designation and funding continued from the military . However , the German nuclear power project was then broken down into the following main areas : uranium and heavy water production , uranium isotope separation , and the " Uranmaschine " ( uranium machine , i . e . , nuclear reactor ) . Also , the project was then essentially split up between a number of institutes , where the directors dominated the research and set their own research agendas . The dominant personnel , facilities , and areas of research were : The point in 1942 , when the army relinquished its control of the German nuclear energy project , was the zenith of the project relative to the number of personnel devoted to the effort . There were only about seventy scientists working on the project , with about forty devoting more than half their time to nuclear fission research . After this , the number of scientists working on applied nuclear fission diminished dramatically . Many of the scientists not working with the main institutes stopped working on nuclear fission and devoted their efforts to more pressing war related work . On 4 June 1942 , a conference initiated by the " Reich Minister for Armament and Ammunition " Albert Speer regarding the nuclear energy project , had decided its continuation merely for the aim of energy production . On 9 June 1942 , Adolf Hitler issued a decree for the reorganization of the RFR as a separate legal entity under the " Reichsministerium für Bewaffnung und Munition " ( RMBM , Reich Ministry for Armament and Ammunition , after autumn 1943 the Reich Ministry for Armament and War Production ) ; the decree appointed Reich Marshal Hermann Göring as the president . The reorganization was done under the initiative of Minister Albert Speer of the RMBM ; it was necessary as the RFR under Minister Bernhard Rust was ineffective and not achieving its purpose . It was the hope that Göring would manage the RFR with the same discipline and efficiency as he had in the aviation sector . A meeting was held on 6 July 1942 to discuss the function of the RFR and set its agenda . The meeting was a turning point in National Socialism ' s attitude towards science , as well as recognition that its policies which drove Jewish scientists out of Germany were a mistake , as the Reich needed their expertise . Abraham Esau was appointed on 8 December 1942 as Hermann Göring ' s " Bevollmächtigter " ( plenipotentiary ) for nuclear physics research under the RFR ; in December 1943 , Esau was replaced by Walther Gerlach . In the final analysis , placing the RFR under Göring ' s administrative control had little effect on the German nuclear energy project . Over time , the HWA and then the RFR controlled the German nuclear energy project . The most influential people were Kurt Diebner , Abraham Esau , Walther Gerlach , and Erich Schumann . Schumann was one of the most powerful and influential physicists in Germany . Schumann was director of the Physics Department II at the Frederick William University ( later , University of Berlin ) , which was commissioned and funded by the " Oberkommando des Heeres " ( OKH , Army High Command ) to conduct physics research projects . He was also head of the research department of the HWA , assistant secretary of the Science Department of the OKW , and " Bevollmächtigter " ( plenipotentiary ) for high explosives . Diebner , throughout the life of the nuclear energy project , had more control over nuclear fission research than did Walther Bothe , Klaus Clusius , Otto Hahn , Paul Harteck , or Werner Heisenberg . Isotope separation . Heinz Ewald , a member of the " Uranverein " , had proposed an electromagnetic isotope separator , which was thought applicable to U production and enrichment . This was picked up by Manfred von Ardenne , who ran a private research establishment . In 1928 , von Ardenne had come into his inheritance with full control as to how it could be spent , and he established his private research laboratory the " Forschungslaboratoriums für Elektronenphysik " , in Berlin - Lichterfelde , to conduct his own research on radio and television technology and electron microscopy . He financed the laboratory with income he received from his inventions and from contracts with other concerns . For example , his research on nuclear physics and high - frequency technology was financed by the " Reichspostministerium " ( RPM , Reich Postal Ministry ) , headed by Wilhelm Ohnesorge . Von Ardenne attracted top - notch personnel to work in his facility , such as the nuclear physicist Fritz Houtermans , in 1940 . Von Ardenne had also conducted research on isotope separation . Taking Ewald ' s suggestion he began building a prototype for the RPM . The work was hampered by war shortages and ultimately ended by the war . Moderator production . The production of heavy water was already under way in Norway when the Nazis invaded on April 9 , 1940 . The Norwegian production of heavy water was quickly secured and improved by Nazis . The takeover and eventual sabotage was depicted in the movie , The Heroes of Telemark ( 1965 ) . Internal reports . Reports from the research conducted were published in " Kernphysikalische Forschungsberichte " ( " Research Reports in Nuclear Physics " ) , an internal publication of the " Uranverein " . The reports were classified Top Secret , they had very limited distribution , and the authors were not allowed to keep copies . The reports were confiscated under the Allied Operation Alsos and sent to the United States Atomic Energy Commission for evaluation . In 1971 , the reports were declassified and returned to Germany . The reports are available at the Karlsruhe Nuclear Research Center and the American Institute of Physics . Individual reports are cited on the pages for some of the research participants in the " Uranverein " ; see for example Friedrich Bopp , Kurt Diebner , Klara Döpel , Robert Döpel , Siegfried Flügge , Paul Harteck , Walter Herrmann , Karl - Heinz Höcker , Fritz Houtermans , Horst Korsching , Georg Joos , Heinz Pose , Carl Ramsauer , Fritz Strassmann , Karl Wirtz , and Karl Zimmer . Politicization . Two factors which had deleterious effects on the nuclear energy project were the politicization of the education system under National Socialism and the rise of the " Deutsche Physik " movement , which was anti - Semitic and had a bias against theoretical physics , especially quantum mechanics . Emigrations . Adolf Hitler took power on 30 January 1933 . On 7 April , the Law for the Restoration of the Professional Civil Service was enacted ; this law , and its subsequent related ordinances , politicized the education system in Germany . This had immediate deleterious effects on the physics capabilities of Germany . Furthermore , combined with the " Deutsche Physik " movement , the deleterious effects were intensified and prolonged . The consequences to physics in Germany and its subfield of nuclear physics were multifaceted . An immediate consequence upon passage of the law was that it produced both quantitative and qualitative losses to the physics community . Numerically , it has been estimated that a total of 1 , 145 university teachers , in all fields , were driven from their posts , which represented about 14 % of the higher learning institutional staff members in 1932 – 1933 . Out of 26 German nuclear physicists cited in the literature before 1933 , 50 % emigrated . Qualitatively , 10 physicists and four chemists who had won or would win the Nobel Prize emigrated from Germany shortly after Hitler came to power , most of them in 1933 . These 14 scientists were : Hans Bethe , Felix Bloch , Max Born , Albert Einstein , James Franck , Peter Debye , Dennis Gabor , Fritz Haber , Gerhard Herzberg , Victor Hess , George de Hevesy , Erwin Schrödinger , Otto Stern , and Eugene Wigner . Britain and the USA were often the recipients of the talent which left Germany . The University of Göttingen had 45 dismissals from the staff of 1932 – 1933 , for a loss of 19 % . Eight students , assistants , and colleagues of the Göttingen theoretical physicist Max Born left Europe after Hitler came to power and eventually found work on the Manhattan Project , thus helping the United States , Britain and Canada to develop the atomic bomb ; they were Enrico Fermi , James Franck , Maria Goeppert - Mayer , Robert Oppenheimer , Edward Teller , Victor Weisskopf , Eugene Wigner , and John von Neumann . Otto Robert Frisch , who with Rudolf Peierls first calculated the critical mass of U - 235 needed for an explosive , was also a Jewish refugee . Max Planck , the father of quantum theory , had been right in assessing the consequences of National Socialist policies . In 1933 , Planck , as president of the " Kaiser Wilhelm Gesellschaft " ( Kaiser Wilhelm Society ) , met with Adolf Hitler . During the meeting , Planck told Hitler that forcing Jewish scientists to emigrate would mutilate Germany and the benefits of their work would go to foreign countries . Hitler responded with a rant against Jews and Planck could only remain silent and then take his leave . The National Socialist regime would only come around to the same conclusion as Planck in the 6 July 1942 meeting regarding the future agenda of the " Reichsforschungsrat " ( RFR , Reich Research Council ) , but by then it was too late . Heisenberg affair . The politicization of the education system essentially replaced academic tradition and excellence with ideological adherence and trappings , such as membership in National Socialist organizations , such as the " Nationalsozialistische Deutsche Arbeiterpartei " ( NSDAP , National Socialist German Workers Party ) , the " Nationalsozialistischer Deutscher Dozentenbund " ( NSDDB , National Socialist German University Lecturers League ) , and the " Nationalsozialistischer Deutscher Studentenbund " ( NSDStB , National Socialist German Student League ) . The politicization can be illustrated with the conflict which evolved when a replacement for Arnold Sommerfeld was sought in view of his emeritus status . The conflict involved one of the prominent " Uranverein " participants , Werner Heisenberg . On 1 April 1935 Arnold Sommerfeld , Heisenberg ' s teacher and doctoral advisor at the University of Munich , achieved emeritus status . However , Sommerfeld stayed on as his own temporary replacement during the selection process for his successor , which took until 1 December 1939 . The process was lengthy due to academic and political differences between the Munich Faculty ' s selection and that of both the " Reichserziehungsministerium " ( REM , Reich Education Ministry ) and the supporters of " Deutsche Physik " . In 1935 , the Munich Faculty drew up a candidate list to replace Sommerfeld as ordinarius professor of theoretical physics and head of the Institute for Theoretical Physics at the University of Munich . There were three names on the list : Werner Heisenberg , who received the Nobel Prize in Physics in 1932 , Peter Debye , who would receive the Nobel Prize in Chemistry in 1936 , and Richard Becker — all former students of Sommerfeld . The Munich Faculty was firmly behind these candidates , with Heisenberg as their first choice . However , supporters of " Deutsche Physik " and elements in the REM had their own list of candidates and the battle commenced , dragging on for over four years . During this time , Heisenberg came under vicious attack by the supporters of " deutsche Physik . " One such attack was published in " Das Schwarze Korps " , the newspaper of the " Schutzstaffel " , or SS , headed by Heinrich Himmler . In the editorial , Heisenberg was called a " White Jew " who should be made to " disappear . " These verbal attacks were taken seriously , as Jews were subject to physical violence and incarceration at the time . Heisenberg fought back with an editorial and a letter to Himmler , in an attempt to get a resolution to this matter and regain his honour . At one point , Heisenberg ' s mother visited Himmler ' s mother to help bring a resolution to the affair . The two women knew each other as a result of Heisenberg ' s maternal grandfather and Himmler ' s father being rectors and members of a Bavarian hiking club . Eventually , Himmler settled the Heisenberg affair by sending two letters , one to " SS - Gruppenführer " Reinhard Heydrich and one to Heisenberg , both on 21 July 1938 . In the letter to Heydrich , Himmler said Germany could not afford to lose or silence Heisenberg as he would be useful for teaching a generation of scientists . To Heisenberg , Himmler said the letter came on recommendation of his family and he cautioned Heisenberg to make a distinction between professional physics research results and the personal and political attitudes of the involved scientists . The letter to Heisenberg was signed under the closing " " Mit freundlichem Gruss und , Heil Hitler ! " " ( " With friendly greetings , Heil Hitler ! " ) Overall , the settlement of the Heisenberg affair was a victory for academic standards and professionalism . However , the replacement of Sommerfeld by Wilhelm Müller on 1 December 1939 was a victory of politics over academic standards . Müller was not a theoretical physicist , had not published in a physics journal , and was not a member of the " Deutsche Physikalische Gesellschaft " ( DPG , German Physical Society ) ; his appointment as a replacement for Sommerfeld was considered a travesty and detrimental to educating a new generation of theoretical physicists . Missing generation of physicists . Politicization of the academic community , combined with the impact of the " Deutsche Physik " movement and other policies , such as drafting physicists to fight in the war ( e . g . , Paul O . Müller , a member of the " Uranverein " who died on the Russian front ) , had the net effect of bringing about a missing generation of physicists . At the close of the war , physicists born between 1915 and 1925 were almost nonexistent . Autonomy and accommodation . Members of the " Uranverein " , Wolfgang Finkelnburg , Werner Heisenberg , Carl Ramsauer , and Carl Friedrich von Weizsäcker were effective in countering the politicization of academia and effectively putting an end to the influence of the " Deutsche Physik " movement . However , in order to do this they were , as were many scientists , caught between autonomy and accommodation . Essentially , they would have to legitimize the National Socialist system by compromise and collaboration . During the period in which " Deutsche Physik " was gaining prominence , a foremost concern of the great majority of scientists was to maintain autonomy against political encroachment . Some of the more established scientists , such as Max von Laue , could demonstrate more autonomy than the younger and less established scientists . This was , in part , due to political organizations , such as the " Nationalsozialistischer Deutscher Dozentenbund " ( National Socialist German University Lecturers League ) , whose district leaders had a decisive role in the acceptance of an " Habilitationsschrift " , which was a prerequisite to attaining the rank of " Privatdozent " necessary to becoming a university lecturer . While some with ability joined such organizations out of tactical career considerations , others with ability and adherence to historical academic standards joined these organizations to moderate their activities . This was the case of Finkelnburg . It was in the summer of 1940 that Finkelnburg became an acting director of the NSDDB at " Technische Hochschule " , Darmstadt . As such , he organized the " Münchner Religionsgespräche " , which took place on 15 November 1940 and was known as the " Munich Synod " . The " Münchner Religionsgespräche " was an offensive against " deutsche Physik " . While the technical outcome may have been thin , it was a political victory against " deutsche Physik " . Also , in part , it was Finkelnburg ' s role in organising this event that influenced Carl Ramsauer , as president of the " Deutsche Physikalische Gesellschaft " , to select Finkelnburg in 1941 as his deputy . Finkelnburg served in this capacity until the end of World War II . Early in 1942 , as president of the DPG , Ramsauer , on Felix Klein ' s initiative and with the support of Ludwig Prandtl , submitted a petition to Reich Minister Bernhard Rust , at the " Reichserziehungsministerium " ( Reich Education Ministry ) . The petition , a letter and six attachments , addressed the atrocious state of physics instruction in Germany , which Ramsauer concluded was the result of politicization of education . Exploitation and denial . Near the end of World War II , the principal Allied war powers made plans for exploitation of German science . In light of the implications of nuclear weapons , German nuclear fission and related technologies were singled out for special attention . In addition to exploitations , denial was an element of their efforts , i . e . , the Americans and Russians conducted their respective operations to try to deny German technology , personnel , and material to the other party . Application of denial often meant getting there first , which to some extent put the Russians at a disadvantage in some geographic locations , even if the area was to be in the Russian zone of occupation . When it came to applications of exploitation and denial , all parties were sometimes heavy - handed . A general US denial and exploitation effort was Operation Paperclip . Operations directed specifically towards German nuclear fission were Operation Alsos and Operation Epsilon , the latter being done in collaboration with the British . In lieu of the codename for the Russian operation , if it had one , it has been referred to by Oleynikov as the Russian " Alsos " . American and British . Berlin had been a location of many German scientific research facilities . To limit casualties and loss of equipment , many of these facilities were dispersed to other locations in the latter years of the war . Unfortunately for the Russians , the " Kaiser - Wilhelm - Institut für Physik " ( KWIP , Kaiser Wilhelm Institute for Physics ) had mostly been moved in 1943 and 1944 to Hechingen and its neighboring town of Haigerloch , on the edge of the Black Forest , which eventually became the French occupation zone . This move allowed the Americans to take into custody a large number of German scientists associated with nuclear research . The only section of the institute which remained in Berlin was the low - temperature physics section , headed by Ludwig Bewilogua , who was in charge of the exponential uranium pile . Nine of the prominent German scientists who published reports in " Kernphysikalische Forschungsberichte " as members of the " Uranverein " were picked up by Operation Alsos and incarcerated in England under Operation Epsilon : Erich Bagge , Kurt Diebner , Walther Gerlach , Otto Hahn , Paul Harteck , Werner Heisenberg , Horst Korsching , Carl Friedrich von Weizsäcker , and Karl Wirtz . Also , incarcerated was Max von Laue , although he had nothing to do with the nuclear energy project . Goudsmit , the chief scientific advisor to Operation Alsos , thought von Laue might be beneficial to the postwar rebuilding of Germany and would benefit from the high level contacts he would have in England . With the interest of the " Heereswaffenamt " ( HWA , Army Ordnance Office ) , Nikolaus Riehl , and his colleague Günter Wirths , set up an industrial - scale production of high - purity uranium oxide at the " Auergesellschaft " plant in Oranienburg . Adding to the capabilities in the final stages of metallic uranium production were the strength ' s of the Degussa corporation ' s capabilities in metals production . The Oranienburg plant provided the uranium sheets and cubes for the " Uranmaschine " experiments conducted at the KWIP and the " Versuchsstelle " ( testing station ) of the " Heereswaffenamt " ( Army Ordnance Office ) in Gottow . The G - 1 experiment performed at the HWA testing station , under the direction of Kurt Diebner , had lattices of 6 , 800 uranium oxide cubes ( about 25 tons ) , in the nuclear moderator paraffin . Work of the American Operation Alsos teams , in November 1944 , uncovered leads which took them to a company in Paris that handled rare earths and had been taken over by the " Auergesellschaft " . This , combined with information gathered in the same month through an Alsos team in Strasbourg , confirmed that the Oranienburg plant was involved in the production of uranium and thorium metals . Since the plant was to be in the future Soviet zone of occupation and the Red Army ' s troops would get there before the Allies , General Leslie Groves , commander of the Manhattan Project , recommended to General George Marshall that the plant be destroyed by aerial bombardment , in order to deny its uranium production equipment to the Soviets . On 15 March 1945 , 612 B - 17 Flying Fortress bombers of the Eighth Air Force dropped 1 , 506 tons of high - explosive and 178 tons of incendiary bombs on the plant . Riehl visited the site with the Russians and said that the facility was mostly destroyed . Riehl also recalled long after the war that the Soviets knew precisely why the Americans had bombed the facility — the attack had been directed at them rather than the Germans . French . From 1941 to 1947 , Fritz Bopp was a staff scientist at the KWIP , and worked with the " Uranverein " . In 1944 , when most of the KWIP was evacuated to Hechingen in Southern Germany due to air raids on Berlin , he went there too , and he was the Institute ' s Deputy Director there . When the American Alsos Mission evacuated Hechingen and Haigerloch , near the end of World War II , French armed forces occupied Hechingen . Bopp did not get along with them and described the initial French policy objectives towards the KWIP as exploitation , forced evacuation to France , and seizure of documents and equipment . The French occupation policy was not qualitatively different from that of the American and Russian occupation forces , it was just carried out on a smaller scale . In order to put pressure on Bopp to evacuate the KWIP to France , the French Naval Commission imprisoned him for five days and threatened him with further imprisonment if he did not cooperate in the evacuation . During his imprisonment , the spectroscopist Hermann Schüler , who had a better relationship with the French , persuaded the French to appoint him as Deputy Director of the KWIP . This incident caused tension between the physicists and spectroscopists at the KWIP and within its umbrella organization the " Kaiser - Wilhelm Gesellschaft " ( Kaiser Wilhelm Society ) . Soviet . At the close of World War II , the Soviet Union had special search teams operating in Austria and Germany , especially in Berlin , to identify and " requisition " equipment , material , intellectual property , and personnel useful to the Soviet atomic bomb project . The exploitation teams were under the Soviet Alsos and they were headed by Lavrentij Beria ' s deputy , Colonel General A . P . Zavenyagin . These teams were composed of scientific staff members , in NKVD officer ' s uniforms , from the bomb project ' s only laboratory , Laboratory No . 2 , in Moscow , and included Yulij Borisovich Khariton , Isaak Konstantinovich Kikoin , and Lev Andreevich Artsimovich . Georgij Nikolaevich Flerov had arrived earlier , although Kikoin did not recall a vanguard group . Targets on the top of their list were the " Kaiser - Wilhelm Institut für Physik " ( KWIP , Kaiser Wilhelm Institute for Physics ) , the Frederick William University ( today , the University of Berlin ) , and the " Technische Hochschule Berlin " ( today , the " Technische Universität Berlin " ( Technical University of Berlin " ) . German physicists who worked on the " Uranverein " and were sent to the Soviet Union to work on the Soviet atomic bomb project included : Werner Czulius , Robert Döpel , Walter Herrmann , Heinz Pose , Ernst Rexer , Nikolaus Riehl , and Karl Zimmer . Günter Wirths , while not a member of the " Uranverein " , worked for Riehl at the " Auergesellschaft " on reactor - grade uranium production and was also sent to the Soviet Union . Zimmer ' s path to work on the Soviet atomic bomb project was through a prisoner of war camp in Krasnogorsk , as was that of his colleagues Hans - Joachim Born and Alexander Catsch from the " Kaiser - Wilhelm Institut für Hirnforschung " ( KWIH , Kaiser Wilhelm Institute for Brain Research , today the " Max - Planck Institut für Hirnforschung " ) , who worked there for N . V . Timofeev - Resovskij , director of the " Abteilung für Experimentelle Genetik " ( Department of Experimental Genetics ) . All four eventually worked for Riehl in the Soviet Union at Laboratory B in Sungul ' . Von Ardenne , who had worked on isotope separation for the " Reichspostministerium " ( Reich Postal Ministry ) , was also sent to the Soviet Union to work on their atomic bomb project , along with Gustav Hertz , Nobel laureate and director of Research Laboratory II at Siemens , Peter Adolf Thiessen , director of the " Kaiser - Wilhelm Institut für physikalische Chemie und Elektrochemie " ( KWIPC , Kaiser Wilhelm Institute for Chemistry and Electrochemisty , today the Fritz Haber Institute of the Max - Planck Society ) , and Max Volmer , director of the Physical Chemistry Institute at the Berlin " Technische Hochschule " ( Technical University of Berlin ) , who all had made a pact that whoever first made contact with the Soviets would speak for the rest . Before the end of World War II , Thiessen , a member of the Nazi Party , had Communist contacts . On 27 April 1945 , Thiessen arrived at von Ardenne ' s institute in an armored vehicle with a major of the Soviet Army , who was also a leading Soviet chemist , and they issued Ardenne a protective letter ( " Schutzbrief " ) . Comparison of the Manhattan Project and the " Uranverein " . The joint American , British , and Canadian Manhattan Project developed the uranium and plutonium atomic bombs . Its success is attributable to meeting all four of the following conditions : Even with all four of these conditions in place the Manhattan Project succeeded only after the war in Europe had been brought to a conclusion . Mutual distrust existed between the German government and some scientists . For the Manhattan Project , the second condition was met on 9 October 1941 or shortly thereafter . Germany fell short of what was required to make an atomic bomb . Significant here is that by the end of 1941 it was already apparent that the German nuclear energy project would not make a decisive contribution to ending the German war effort in the near term , and control of the project was relinquished by the " Heereswaffenamt " ( HWA , Army Ordnance Office ) to the " Reichsforschungsrat " ( RFR , Reich Research Council ) in July 1942 . Concerning condition three , the needs in materiel and manpower for a large - scale project necessary for the separation of isotopes for a uranium - based bomb and heavy water production for reactors for a plutonium - based bomb may have been possible in the early years of the war . As to condition four , the high priority allocated to the Manhattan Project allowed for the recruitment and concentration of capable scientists on the project . In Germany , on the other hand , a great many young scientists and technicians who would have been of great use to such a project were conscripted into the German armed forces , while others had fled the country before the war due to antisemitism and political persecution . Whereas Enrico Fermi , a scientific Manhattan leader , had an " " unique double aptitude for theoretical and experimental work " " in the 20th century , the successes at Leipzig until 1942 resulted from the cooperation between the theoretical physicist Werner Heisenberg and the experimentalist Robert Döpel . Most important was their experimental proof of an effective neutron increase in April 1942 . At the end of July of the same year , the group around Fermi also succeeded in the neutron increase within a reactor - like arrangement . In June 1942 , Döpels " " Uran - Maschine " " was destroyed by a chemical explosion introduced by hydrogen , which finished the work on this topic at Leipzig . Thereafter , despite increased expenditures the Berlin groups and their extern branches didn ' t succeed in getting a reactor critical until the end of World War II . However , this was realized by the Fermi group in December 1942 , so that the German advantage was definitively lost , even with respect to research on energy production . Recent developments . A book by Rainer Karlsch , " Hitlers Bombe " , published in 2005 , alleged that Diebner ' s team conducted the first successful nuclear weapon test of some type ( employing hollow charges for ignition ) of nuclear - related device in Ohrdruf , Thuringia on 4 March 1945 . However , Karlsch has been criticized for displaying " a catastrophic lack of understanding of physics " by physicist Michael Schaaf , who is himself the author of an earlier 2001 book about Nazi atomic research which controversially paints Heisenberg as a pacifist who allegedly tried to prevent development of a Nazi nuclear weapon , while Karlsch himself has acknowledged that he lacked absolute proof for the claims made in his book . Shaaf ' s own motives for denouncing Karlsch might be explained by the underlying theory expounded in Michael Schaaf ' s book that Heisenberg did not support development of a nuclear weapon which was discredited in Karlsch ' s 2005 work which uncovered Heisenberg ' s speech notes from the Harnack Haus conference of July 1942 , located in KGB archives at Moscow . These speech notes revealed Heisenberg was a strong advocate for development of a Nazi nuclear weapon . Retired Luftwaffe Field Marshall Erhard Milch also recounted and corroborated the speech notes found in KGB archives . A similar project was described in David Irving ' s 1967 book " The Virus House " , where it was claimed that some of Diebner ' s researchers had unsuccessfully attempted to produce fusion using conventional explosives and heavy paraffin as a deuterium carrier . Irving also describes a further experiment in 1943 carried out by Trinks and Sachsse , which used a hollow sphere of silver filled with deuterium , imploded by conventional explosives . Again it was unsuccessful , no trace of radioactivity being produced . Science historian Mark Walker also published his analysis in 2005 , and in 2005 Karlsch and Walker published an article on the controversial historical evidence , briefly referenced in the article . The " Physikalisch - Technische Bundesanstalt " ( PTB , Federal Physical and Technical Institute ) tested soil samples in the area of the alleged test , and in 2006 it issued its results : " keinen Befund " ( nothing found ) . Karlsch published a follow - on book with Heinko Petermann to elaborate on issues raised in his first book .