Question: Who was the uncle of German physicist and philosopher who was the longest-living member of the team which performed nuclear research in Germany during the Second World War?
Context: The Saclay Nuclear Research Centre is one of 9 laboratories belonging to the Commissariat à l'énergie atomique (CEA), which hosts the administrative headquarters of the CEA and a major national laboratory.  It is the heart of French nuclear research since Frederic Joliot-Curie founded it after the Second World War.  Its campus has been built by famous architect Perret. Josef Schintlmeister (16 June 1908, Radstadt – 14 August 1971, Hinterglemm) was an Austrian-German nuclear physicist and alpinist from Radstadt.  During World War II, he worked on the German nuclear energy project, also known as the Uranium Club.  After World War II, he was sent Russia to work on the Soviet atomic bomb project.  After he returned to Vienna, he took positions in East Germany.  He was a professor of physics at the "Technische Hochschule Dresden" as well holding a leading scientific position at the Rossendorf Central Institute for Nuclear Research. Heinz Barwich (22 July 1911 in Berlin – 10 April 1966 in Cologne) was a German nuclear physicist.  He was deputy director of the Siemens Research Laboratory II in Berlin.  At the close of World War II, he followed the decision of Gustav Hertz, to go to the Soviet Union for ten years to work on the Soviet atomic bomb project, for which he received the Stalin Prize.  He was director of the "Zentralinstitut für Kernforschung" (Central Institute for Nuclear Research) at Rossendorf near Dresden.  For a few years he was director of the Joint Institute for Nuclear Research in Dubna, Russia.  In 1964 he defected to the West. Rudolf Fleischmann (1 May 1903 – 3 February 2002) was a German experimental nuclear physicist from Erlangen, Bavaria.  He worked for Walther Bothe at the Physics Institute of the University of Heidelberg and then at the Institute for Physics of the Kaiser Wilhelm Institute for Medical Research.  Through his association with Bothe, he became involved in the German nuclear energy project, also known as the Uranium Club; one of Fleischmann’s areas of interest was isotope separation techniques.  In 1941 he was appointed associate professor of experimental physics at the newly established Reichsuniversität Straßburg, in France.  Late in 1944, he was arrested under the American Operation Alsos and sent to the United States.  After he returned to Germany 1946, he became Director of the State Physical Institute at the University of Hamburg and developed it as a center of nuclear research.  In 1953, he took a position at the University of Erlangen and achieved "emeritus" status in 1969.  He was a signatory of the Göttingen Manifesto in 1957. Carl Friedrich Freiherr von Weizsäcker (28 June 1912 – 28 April 2007) was a German physicist and philosopher.  He was the longest-living member of the team which performed nuclear research in Germany during the Second World War, under Werner Heisenberg's leadership.  There is ongoing debate as to whether or not he and the other members of the team actively and willingly pursued the development of a nuclear bomb for Germany during this time. Viktor Freiherr von Weizsäcker (21 April 1886 in Stuttgart – 9 January 1957 in Heidelberg) was a German physician and physiologist.  He was the brother of Ernst von Weizsäcker, and uncle to Richard von Weizsäcker and Carl Friedrich von Weizsäcker.  (For his family tree, see Weizsäcker.) Karl Lintner (1917 - 11.2.2015) is an Austrian nuclear physicist.  During World War II, he worked on the German nuclear energy project, also known as the Uranium Club; he did research on the inelastic dispersion of fast neutrons in uranium.  After the war, he taught and did nuclear research at the University of Vienna.  He was a full member of the Austrian Academy of Sciences. Forschungsreaktor 2 (FR2) ("Research Reactor 2") was the second nuclear reactor built in and by Germany after restrictions on nuclear research imposed as a result of the Second World War were lifted in 1955.  Construction began in 1957 in Eggenstein-Leopoldshafen/BW.  The organization charged with the project evolved into the "Kernforschungszentrum Karlsruhe (KfK)" (Karlsruhe Nuclear Research Centre), which in turn evolved into the present day Karlsruhe Institute of Technology (KIT). He did pioneering work which contributed to the understanding nuclear energy levels.  He worked on the German nuclear energy project "Uranverein".  After World War II, the Soviet Union sent him to establish and head Laboratory V in Obninsk.  From 1957, he was at the "Joint Institute for Nuclear Research" in Dubna, Russia.  He settled in East Germany in 1959, and he held teaching posts and directed nuclear physics institutes at the "Technische Hochschule" Dresden. The Helmholtz-Zentrum Dresden-Rossendorf (HZDR) is a German research laboratory in Dresden and member of the Helmholtz Association of German Research Centres.  Research is conducted in three of the Helmholtz Association's research areas: matter, health, and energy.  While the research center was formerly known as "Forschungszentrum Dresden-Rossendorf" (since 1992), the research site dates back as far as 1956, when the "Zentralinstitut für Kernforschung" (national institute for nuclear research) in East Germany was founded.
Answer: Viktor Freiherr von Weizsäcker