Question: What group was tasked with making nuclear weapons in April of 1939, and was sabotaged by the Allied Nations in World War II?

<P0-S0> "Atomic spies" or "atom spies" were people in the United States, Great Britain, and Canada who are known to have illicitly given information about nuclear weapons production or design to the Soviet Union during World War II and the early Cold War. <P0-S1>  Exactly what was given, and whether everyone on the list gave it are still matters of some scholarly dispute, and in some cases, what were originally seen as strong testimonies or confessions were admitted as fabricated in later years. <P0-S2>  Their work constitutes the most publicly well-known and well-documented case of nuclear espionage in the history of nuclear weapons. <P0-S3>  There was a movement among nuclear scientists to share the information with the world scientific community, but it was firmly quashed by the U.S. government. <SEP> <P1-S0> The World Federation of Democratic Youth (WFDY) is an international youth organization, recognized by the United Nations as an international youth non-governmental organization, and has historically characterized itself as anti-imperialist and left-wing. <P1-S1>  WFDY was founded in London in 1945 as a broad international youth movement, organized in the context of the end of World War II with the aim of uniting youth from the Allied nations behind an anti-fascist platform that was broadly pro-peace, anti-nuclear war, expressing friendship between youth of the capitalist and socialist nations. <P1-S2>  The WFDY Headquarters are in Budapest, Hungary. <P1-S3>  The main event of WFDY is the World Festival of Youth and Students. <P1-S4>  The last festival was successfully held in Quito, Ecuador, in December 2013. <P1-S5>  It was one of the first organizations granted general consultative status with the United Nations Economic and Social Council. <SEP> <P2-S0>  During World War II, the Allies decided to remove the heavy water supply and destroy the heavy water plant in order to inhibit the German development of nuclear weapons. <P2-S1> The Norwegian heavy water sabotage (Bokmål: "Tungtvannsaksjonen" , Nynorsk: "Tungtvassaksjonen" ) was a series of operations undertaken by Norwegian saboteurs during World War II to prevent the German nuclear weapon project from acquiring heavy water (deuterium oxide), which could have been used by the Germans to produce nuclear weapons. <P2-S2>  In 1934, at Vemork, Norway, Norsk Hydro built the first commercial plant capable of producing heavy water as a byproduct of fertilizer production. <P2-S3>  It had a capacity of 12 tonnes per year. <P2-S4>  Raids were aimed at the 60 MW Vemork power station at the Rjukan waterfall in Telemark, Norway. <SEP> <P3-S0> The German nuclear weapon project (German: "Uranprojekt" ; informally known as the "Uranverein"; English: Uranium Society or Uranium Club ) was a scientific effort led by Germany to develop and produce nuclear weapons during World War II. <P3-S1>  The first effort started in April 1939, just months after the discovery of nuclear fission in December 1938, but ended only months later due to the German invasion of Poland, after many notable physicists were drafted into the "Wehrmacht".