Walter Zinn

Walter Henry Zinn was a Canadian-born American nuclear engineer and physicist who directed construction of the world's first nuclear reactor. Working on the Manhattan Project's Metallurgical Laboratory during the Second World War, he supervised the building of Chicago Pile-1, which achieved the first controlled, self-sustaining nuclear chain reaction on December 2, 1942, at the University of Chicago, and he went on to oversee the follow-on Chicago Pile-2 and Chicago Pile-3 reactors. From 1946 to 1956 he served as the first director of Argonne National Laboratory, where he led the design and construction of Experimental Breeder Reactor I, nicknamed Zip, which on December 20, 1951 became the first reactor to generate electricity for a building. His laboratory's reactor research also contributed to the development of naval nuclear propulsion, including the reactor used in the USS Nautilus, the first nuclear-powered submarine. He was elected the first president of the American Nuclear Society in 1955 and later received the Atoms for Peace Award in 1960 and the Enrico Fermi Award in 1969.