Question: What project was a scientific effort led by Germany to develop and produce nuclear weapons during World War II, and was subject to the Norweigian heavy water sabotage to prevent it?

Context articles: P-9 Project
Norwegian heavy water sabotage
Nuclear weapons debate
Jomar Brun
Operation Freshman
The Heavy Water War
Vemork
German nuclear weapon project
United States and weapons of mass destruction
Fritz Johann Hansgirg

The P-9 Project was the codename given during World War II to the Manhattan Project's heavy water production program.
 The Cominco plant at Trail, British Columbia, was upgraded to produce heavy water.
 DuPont built three plants in the United States: at the Morgantown Ordnance Works, near Morgantown, West Virginia; at the Wabash River Ordnance Works, near Dana and Newport, Indiana; and at the Alabama Ordnance Works, near Childersburg and Sylacauga, Alabama.
 The American plants operated from 1943 until 1945.
 The Canadian plant at Trail continued in operation until 1956.
 Three nuclear reactors were built using the heavy water produced by the P-9 Project: Chicago Pile 3 at Argonne, and ZEEP and NRX at the Chalk River Laboratories in Canada.
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.
 In 1934, at Vemork, Norway, Norsk Hydro built the first commercial plant capable of producing heavy water as a byproduct of fertilizer production.
 It had a capacity of 12 tonnes per year.
 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.
 Raids were aimed at the 60 MW Vemork power station at the Rjukan waterfall in Telemark, Norway.
The nuclear weapons debate refers to the controversies surrounding the threat, use and stockpiling of nuclear weapons.
 Even before the first nuclear weapons had been developed, scientists involved with the Manhattan Project were divided over the use of the weapon.
 The only time nuclear weapons have been used in warfare was during the final stages of World War II when United States Army Air Forces B-29 Superfortress bombers dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki in early August 1945.
 The role of the bombings in Japan's surrender and the U.S.'s ethical justification for them have been the subject of scholarly and popular debate for decades.
Jomar Brun MBE (18 June 1904 – 26 August 1993) was a Norwegian chemical engineer.
 He was born in Trondheim.
 He graduated from the Norwegian Institute of Technology in 1926, and worked for Norsk Hydro from 1929.
 He was central in the planning and running of the world's first industrial heavy water plant at Norsk Hydro Rjukan.
 During World War II he was called to London, and contributed to the planning phase of Operation Freshman and Operation Gunnerside, the heavy water sabotage at Vemork.
 He was decorated with the Order of the British Empire, and Officer of the French Legion of Honour.
 From 1951 he was appointed professor of electrochemistry at the Norwegian Institute of Technology in Trondheim.
Operation Freshman was the codename given to a British airborne operation conducted in November 1942 during World War II.
 It was the first British airborne operation conducted using gliders, and its target was the Vemork "Norsk Hydro" chemical plant in Telemark, Norway which produced heavy water for Nazi Germany.
 By 1942, the German nuclear weapons programme had come close to being able to develop a nuclear reactor, but in order for the reactor to function it would require a great deal of heavy water.
 The source of the heavy water was the Norsk Hydro plant, which had been occupied in 1940; when the British government learned of the German nuclear developments, it was decided that a raid would be launched to destroy the plant and deny the Germans the heavy water required to develop a nuclear weapon.
 Several tactics were discussed and discarded as impractical, and it was finally decided that a small airborne force composed of sappers from the Royal Engineer units attached to 1st Airborne Division would land by glider a short distance from the plant, demolish it with explosives and then escape over the Norwegian border into Sweden.
The Heavy Water War (original title Kampen om tungtvannet and alternative title The Saboteurs ) is a six-episode war drama TV miniseries produced by the Norwegian Broadcasting Corporation.
 It is a Norwegian/Danish/British co-production, directed by that tells about the German nuclear weapon project and the heavy water sabotage in Norway to disrupt it during the Second World War, with a particular emphasis on the role of Leif Tronstad.
Vemork is the name of a hydroelectric power plant outside Rjukan in Tinn, Norway.
 The plant was built by Norsk Hydro and opened in 1911, its main purpose being to fix nitrogen for the production of fertilizer.
 Vemork was later the site of the first plant in the world to mass-produce heavy water developing from the hydrogen production then used for the Haber process.
 During World War II, Vemork was the target of Norwegian heavy water sabotage operations.
 The heavy water plant was closed in 1971, and in 1988 the power station became the Norwegian Industrial Workers Museum.
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.
 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".
The United States is known to have possessed three types of weapons of mass destruction: nuclear weapons, chemical weapons, and biological weapons.
 The U.S. is the only country to have used nuclear weapons in combat, when it detonated two atomic bombs over the Japanese cities of Hiroshima and Nagasaki during World War II.
 It had secretly developed the earliest form of the atomic weapon during the 1940s under the title "Manhattan Project".
 The United States pioneered the development of both the nuclear fission and hydrogen bombs (the latter involving nuclear fusion).
 It was the world's first and only nuclear power for four years (1945–1949), until the Soviet Union managed to produce its own nuclear weapon.
 The United States has the second largest number of deployed nuclear weapons in the world, after Russia.
Fritz Johann Hansgirg (18911949) was an Austrian electrochemist and metallurgist who in 1928 invented the carbothermic magnesium reduction process (magnesium, like calcium, can be used to reduce uranium oxide to pure uranium metal for use in nuclear weapons), similar to the Pidgeon process.
 In 1934, he left Austria for the Empire of Japan where he worked with industrialist Shitagau Noguchi to set up a magnesium plant and further helped the Japanese build a pilot plant to produce heavy water by the Combined Electrolysis Catalytic Exchange (CECE) he invented.
 Coming to the United States in 1940, he worked with American industrialist Henry J. Kaiser to design a magnesium plant in California, but at the outbreak of World War II, Hansgirg was arrested by the FBI on a Presidential warrant and interned for "the duration of the war."
 After the war, the Soviet Union captured Hansgirg's plants in northern Korea, using the plants' processes and equipment for their atomic bomb project against the United States, likewise, using them in the Manhattan Project, the exact details of which still remain classified in both the United States and Russia.