<P> Cominco had produced electrolytic hydrogen at Trail, British Columbia, since 1930 . Urey suggested in 1941 that it could produce heavy water . To the existing $10 million plant consisting of 3,215 cells consuming 75 MW of hydroelectric power, secondary electrolysis cells were added to increase the deuterium concentration in the water from 2.3% to 99.8% . For this process, Hugh Taylor of Princeton developed a platinum - on - carbon catalyst for the first three stages while Urey developed a nickel - chromia one for the fourth stage tower . The final cost was $2.8 million . The Canadian Government did not officially learn of the project until August 1942 . Trail's heavy water production started in January 1944 and continued until 1956 . Heavy water from Trail was used for Chicago Pile 3, the first reactor using heavy water and natural uranium, which went critical on 15 May 1944 . </P> <P> The Chalk River, Ontario, site was established to rehouse the Allied effort at the Montreal Laboratory away from an urban area . A new community was built at Deep River, Ontario, to provide residences and facilities for the team members . The site was chosen for its proximity to the industrial manufacturing area of Ontario and Quebec, and proximity to a rail head adjacent to a large military base, Camp Petawawa . Located on the Ottawa River, it had access to abundant water . The first director of the new laboratory was Hans von Halban . He was replaced by John Cockcroft in May 1944, who in turn was succeeded by Bennett Lewis in September 1946 . A pilot reactor known as ZEEP (zero - energy experimental pile) became the first Canadian reactor, and the first to be completed outside the United States, when it went critical in September 1945, ZEEP remained in use by researchers until 1970 . A larger 10 MW NRX reactor, which was designed during the war, was completed and went critical in July 1947 . </P> <P> The Eldorado Mine at Port Radium was a source of uranium ore . </P> <P> Although DuPont's preferred designs for the nuclear reactors were helium cooled and used graphite as a moderator, DuPont still expressed an interest in using heavy water as a backup, in case the graphite reactor design proved infeasible for some reason . For this purpose, it was estimated that 3 long tons (3.0 t) of heavy water would be required per month . The P - 9 Project was the government's code name for the heavy water production program . As the plant at Trail, which was then under construction, could produce 0.5 long tons (0.51 t) per month, additional capacity was required . Groves therefore authorized DuPont to establish heavy water facilities 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 . Although known as Ordnance Works and paid for under Ordnance Department contracts, they were built and operated by the Army Corps of Engineers . The American plants used a process different from Trail's; heavy water was extracted by distillation, taking advantage of the slightly higher boiling point of heavy water . </P>

What was the purpose of the manhatten project