Norsk Hydro
The properties of heavy water had been discovered in 1932 by Harold Urey. In 1933, Leif Tronstad and Jomar Brun, the head of Norsk Hydro Rjukan, created a plan for industrial production of heavy water in Norway. As Norsk Hydro were already producing ammonia for nitrogen fertilizer, Tronstad and Brun had realized that large amounts of electrolyzed water were available. Tronstad was paid by Norsk Hydro as a consultant. Already in 1934, Norsk Hydro had opened a plant near the power station at Vemork. This was the world's first plant for industrial mass production of heavy water. Both French and German scientists expressed interest in the project.