Nikolaus Vasilyevich Riehl (; 1901 — 2 August 1990) was a German nuclear chemist of Russian-Jewish descent. Before the fall of Berlin, he was director of the scientific headquarters of the Auergesellschaft AG, and was taken to the Soviet Union.
Riehl was one of many of the German nuclear physicist in the former Soviet program of nuclear weapons, for which, he was recruited in 1945 until 1955 when he was released from the Soviet custody after accepting a technical position at the Technical University of Munich in Germany. He was a recipient of many former Soviet honors which he was awarded for his work in the Soviet Union.
Education Nikolaus Riehl was born in Saint Petersburg, then part of the Russian Empire, in 1901.
His father, Wilhelm Gottfried Riehl, was a German working in Russia as an engineer employed by Siemens; his mother, Elena Riehl (née Kagan) was Russian and was of Jewish descent.Michael D. Gordin, Red Cloud at Dawn: Truman, Stalin, and the End of the Atomic Monopoly, Farrar, Straus and Giroux (2009), p. 145 Riehl was fluent in both German and Russian languages, and attended the German language schools in Russia. The family stayed throughout the World War I and left for Berlin in 1918; he enrolled to attend the chemistry program at the University of Berlin in 1920.
On topics of nuclear science, he collaborated with Otto Hahn on behalf of the Auer Company. Between 1927–29, Riehl defended his thesis in nuclear chemistry, working under Lise Meitner; his thesis contained work on the Geiger-Müller counters for beta ray spectroscopy.Hentschel and Hentschel, 1996, Appendix F; see the entry for Riehl.Riehl and Seitz, 1996, 4-5 and 68.
Career Early years After his doctorate in chemistry, Riehl completed his habilitation but took an employment in the German industry with Auergesellschaft, where he became an authority on luminescence. From 1927, he was a staff scientist in the radiology department and eventually headed the optical engineering department for the company in 1937.Riehl and Seitz, 1996, 8. From 1939 to 1945, he was the director of the scientific headquarters.Riehl and Seitz, 1996, 8.
During this time, Auergesellschaft had a substantial amount of "waste" uranium from which it had extracted radium.Siegfried Flügge Kann der Energieinhalt der Atomkerne technisch nutzbar gemacht werden?, Die Naturwissenschaften Volume 27, Issues 23/24, 402-410 (June 1939). After reading a June 1939 paper by Siegfried Flügge on the technical use of nuclear energy from uranium,Also see the article by Siegfried Flügge Document 74. Siegfried Flügge: Exploiting Atomic Energy. From the Laboratory Experiment to the Uranium Machine – Research Results in Dahlem [15 August 1939] reprinted in English in Hentschel and Hentschel, 1996, 197-206. Riehl recognized a business opportunity for the company, and, in July of that year, went to the Heereswaffenamt (HWA) – the German 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.Hentschel and Hentschel, 1996, 369, Appendix F, see the entry for Riehl, and Appendix D, see the entry for Auergesellschaft.Riehl and Seitz, 1996, 13.
In Russia Near the end of World War II, as the Allied forces were closing in on Berlin, Riehl and some of his staff moved to a village west of Berlin, to try and assure occupation by either the British or American forces. However, in mid-May 1945, with the assistance of Riehl's colleague Karl Zimmer, the Russian physicists Georgy Flyorov and Lev Artsimovich showed up one day in NKVD colonels' uniforms.Riehl and Seitz, 1996, 71-72.Oleynikov, 2000, 7. The use of Russian physicists in the wake of Soviet troop advances to identify and "requisition" equipment, materiel, intellectual property, and personnel useful to the Russian atomic bomb project is similar to the American Operation Alsos. In early 1945, the Soviet war planners initiated the parallel efforts to that of American's where forty out of less than 100 Russian scientists from the Soviet atomic bomb project's Laboratory 2Laboratory 2 was in Moscow. It was later known as LIPAN and then the Kurchatov Institute. See Oleynikov, 2000, 4. went to Germany, Austria, and Czechoslovakia in support of acquisitions for the Russian program.Oleynikov, 2000, 3-5.
The two colonels requested that Riehl join them in Berlin for a few days, where he also met with physicist Yulii Borisovich Khariton, also in the uniform of an NKVD colonel. Riehl and his staff, including their families, were flown to Moscow on 9 July 1945.Riehl and Seitz, 1996, 71-72 and 80.Hentschel and Hentschel, 1996, Appendix F, see the entry for Riehl. Eventually, Riehl's entire laboratory was dismantled and transported to the Soviet Union.Walker, 1993, 183.
Other prominent German scientists from Berlin who were taken to the Soviet Union at that time, and who would cross paths with Riehl, were Manfred von Ardenne, director of his private laboratory Forschungslaboratoriums für Elektronenphysik, Gustav Hertz, Nobel Laureate and director of Research Laboratory II at Siemens, Peter Adolf Thiessen, ordinarius professor at the Humboldt University of Berlin and director of the Kaiser-Wilhelm Institut für physikalische Chemi und Elektrochemie (KWIPC) in Berlin-Dahlem, and Max Volmer, ordinarius professor and director of the Physical Chemistry Institute at Technische Universität Berlin. Soon after being taken to the Soviet Union, Riehl, von Ardenne, Hertz, and Volmer were summoned for a meeting with Lavrentiy Beria, head of the NKVD and the Soviet atomic bomb project.Naimark, 1995, 209-214.Oleynikov, 2000, 10-13.
When a Soviet search team arrived at the Auergesellschaft facility in Oranienburg, they found nearly 100 tons of fairly pure uranium oxide. The Soviet Union took this uranium as reparations, which amounted to between 25% and 40% of the uranium taken from Germany and Czechoslovakia at the end of the war. Khariton said the uranium found there saved the Soviet Union a year on its atomic bomb project.Naimark, 1995, 236.Holloway, 1995, 111.Oleynikov, 2000, 9.
From 1945 to 1950, Riehl was in charge of uranium production at Plant No. 12 in Elektrostal ()Riehl and Seitz, 1996, 89-104. German scientists, who were mostly atomic scientists sent by the Soviets at the end of World War II to work in the Riehl group at Plant No. 12, included A. Baroni (PoW), Hans-Joachim Born, Alexander Catsch (Katsch), Werner Kirst, H. E. Ortmann, Herbert Schmitz (PoW), Walter Sommerfeldt, Herbert Thieme, Günter Wirths, and Karl Günter Zimmer as well as Heinrich Tobien, formerly "Chemiemeister" at Auergesellschaft; Walter Przybilla, brother of Riehl's wife, and mentioned in this context, also spent 10 years in SU, but was not a scientist under Riehl. While Born, Catsch, and Zimmer had collaborated with Riehl in Germany, they were actually not part of Auergesellschaft but with Nikolay Timofeev-Ressovsky's genetics departmentH. J. Born, N. W. Timoféeff-Ressovsky and K. G. Zimmer Biologische Anwendungen des Zählrohres, Naturwissenschaften Volume 30, Number 40, 600-603 (1942). The authors were identified as being in the genetics department of the Kaiser Wilhelm Institute in Berlin-Buch. at the Kaiser-Wilhelm Gesellschaft's Institut für Hirnforschung (KWIH, Kaiser Wilhelm Institute for Brain Research) in Berlin-Buch. Riehl had a hard time incorporating these three into his tasking at Plant No. 12 on his uranium production tasking, as Born was a radiochemist, Catsch was a physician and radiation biologist, and Zimmer was a physicist and radiation biologist.Riehl and Seitz, 1996, 2, 31, 71, 83, 121-128, and 202.Maddrell, 2006, 179-180, 186, 189, and 210-221.Albrecht, Heinemann-Grüder, and Wellmann, 1992, Reference #22 on p. 57.
Elektrostal Plant No. 12, by the last quarter of 1946, was delivering about three metric tons of metallic uranium per week to Laboratory No. 2., which was later known as the Kurchatov Institute. By 1950, Plant No. 12 was producing about one metric ton per day, and it was not the only metallic uranium production plant in operation.Holloway, 1994, 180 and Reference #56 on p. 410.
After the detonation of the Russian uranium bomb, uranium production was going smoothly and Riehl's oversight was no longer necessary at Plant No. 12. Riehl then went, in 1950, to head an institute in Sungul, where he stayed until 1952. Essentially the remaining personnel in his group were assigned elsewhere, with the exception of H. E. Ortmann, A. Baroni (PoW), and Herbert Schmitz (PoW), who went with Riehl. However, Riehl had already sent Born, Catsch, and Zimmer to the institute in December 1947. The German contingent at the institute in Sungul never exceeded 26 – in 1946 there were 95 people at the facility, which grew to 451 by 1955, and the German contingent had already left a few years before that. Besides those already mentioned, other Germans at the institute were Rinatia von Ardenne (sister of Manfred von Ardenne, director of Institute A, in Sukhumi) Wilhelm Menke, Willi Lange (who married the widow of Karl-Heinrich Riewe, who had been at Heinz Pose's Laboratory V, in Obninsk), Joachim Pani, and K. K. Rintelen. The institute in Sungul was responsible for the handling, treatment, and use of radioactive products generated in reactors, as well as radiation biology, dosimetry, and radiochemistry. The institute was known as Laboratory B, and it was overseen by the 9th Chief Directorate of the NKVD (MVD after 1946), the same organization which oversaw the Russian Alsos operation. The scientific staff of Laboratory B – a ShARAShKA – was both Soviet and German, the former being mostly political prisoners or exiles, although some of the service staff were criminals.Riehl and Seitz, 1996, 121-128, and 202.Oleynikov, 2000, 15-17.Penzina, V. V. Archive of the Russian Federal Nuclear Centre of the All-Russian Scientific Research Institute of Technical Physics, named after E. I. Zababakhin. Resource No. 1 – Laboratory "B". [In Russian] (VNIITF ). Penzina is cited as head of the VNIITF Archive in Snezhinsk. (Laboratory V, in Obninsk, headed by Heinz Pose, was also a sharashka and working on the Soviet atomic bomb project. Other notable Germans at the facility were Werner Czulius, Hans Jürgen von Oertzen, Ernst Rexer, and Carl Friedrich Weiss.Polunin, V. V. and V. A. Staroverov Personnel of Special Services in the Soviet Atomic Project 1945 – 1953 [In Russian] (FSB, 2004) .)