In June 1941, Riewe co-authored a paper electron optics and plasma physics with the nuclear physicist Fritz Houtermans. At this time, Houtermans is known to have been at the Forschungslaboratoriums für Elektronenphysik (Research Laboratory for Electron Physics), a private laboratory of Manfred von Ardenne, in Berlin-Lichterfelde. The paper cites the two as being at a facility in Berlin; other papers by Riewe, three years earlier (see below), cited him as being at a facility in the community of Berlin-Wilmersdorf, which is in the vicinity of Berlin-Lichterfelde.
Near the close of World War II, the Soviet Union sent special search teams into Germany to locate and deport German nuclear scientists or any others who could be of use to the Soviet atomic bomb project. The Russian Alsos teams were headed by NKVD Colonel General A. P. Zavenyagin and staffed with numerous scientists, from their only nuclear laboratory, attired in NKVD officer’s uniforms. The main search team, headed by Colonel General Zavenyagin, arrived in Berlin on 3 May, the day after Russia announced the fall of Berlin to their military forces; it included Colonel General V. A. Makhnjov, and nuclear physicists Yulij Borisovich Khariton, Isaak Konstantinovich Kikoin, and Lev Andreevich Artsimovich. Targets on the top of their list were the physics facilities in Berlin and its environs.
Riewe was sent to the Russia to work on the Soviet atomic bomb project, at Heinz Pose’s Laboratory V in Obninsk, either in the initial sweep by the special search teams or later by Pose’s six-month recruitment trip, from March to August 1946, with NKVD General Kravchenko and two other officers.
In 1948, two scientists at Laboratory V, Riewe and Dr. Renger, went on strike for reasons of their work conditions or hoping to be sent back to Germany after their two-year contracts expired. As their actions where while working on a defense project, they were accused of being ring-leaders of sabotage and imprisoned. Riewe received a sentence of 25 years in the Soviet GULAG and disappeared. Tamara Andrjuschenko recalled hearing that Riewe had been executed for sabotage.
Reiwe’s widow moved to Sukhumi, where at that time there was workforce of 300 Germans working at Manfred von Ardenne’s Laboratory A, in Sinop, a suburb of Sukhumi. She eventually married the German draftsman Willi Lange. In 1950, Lange, his wife, Lange’s daughter Hannelora, and his wife’s children by Riewe, moved to Sungul', where he worked at Nikolaus Riehl’s Laboratory B, also known under another cover name, Объект 0211 (Ob'ekt 0211, Object 0211). After 1953, they were quarantined in the Agudzery (Agudseri) transition camp, after which Germans returned to Germany.