[9][10] 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.
: 13 The HWA eventually provided an order for the production of uranium oxide, which took place in the Auergesellschaft plant in Oranienburg, north of Berlin.
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.
[25][26] When a Soviet search team arrived at the Auergesellschaft facility in Oranienburg, they found nearly 100 tons of fairly pure uranium oxide.
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.
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.
[35][36][37] (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.
In 1947, Timofeev-Resovskij was rescued out of a harsh Gulag prison camp, nursed back to health, and sent to Sungul to complete his sentence, but still make a contribution to the Soviet atomic bomb project.
At Laboratory B, Born, Catsch, and Zimmer were able to conduct work similar to that which they had done in Germany, and all three became section heads in Timofeev-Resovskij's department.
The home in which Riehl lived had been designed by Max Volmer and had been previously occupied by Gustav Hertz, when he was director of Laboratory G.[47] For his contributions to the Soviet atomic bomb project, Riehl was awarded a Stalin Prize (first class), a Lenin Prize, and the Hero of Socialist Labor medal.
[51][52][53] While Riehl's work for the Soviet Union netted him significant prestige and wealth, his primary motivation for leaving Russia was freedom.