1934: zwaar-water fabriek gebouwd

The first commer-cial heavy water plant was the Norsk Hydro facility in Norway (built 1934, capacity 12 metric metric tons per year); this is the plant which was attacked by the Allies to deny heavy water to Germany.

Heavy water is the key to one type of reactor in which plutonium can be bred from natural uranium. As such, the production of heavy water has always been monitored, and the material is export controlled.

http://www.fas.org/nuke/intro/nuke/heavy.htm