Walter Zinn, showed that uranium underwent fission when bombarded with neutrons

December 10, 1906, Kitchener (Ontario, Canada) - February 14, 2000, Clearwater (Florida, USA)

In 1930, he received his master's degree from Queens University and, four years later, his doctorate from Columbia University, both in the United States.

He continued his research at the university in atomic fission, with the help of Leó Szilárd. The two showed that uranium underwent fission when bombarded with neutrons, converting part of its mass into energy (according to Albert Einstein's famous equation relating mass and energy). His work with uranium led him to participate in the Manhattan Project at the Metallurgical Laboratory of the University of Chicago (USA). He worked closely with Enrico Fermi to initiate the first self-sustaining nuclear chain reaction at the Chicago Pile-1 reactor on 2 December 1942. He was responsible for removing the control rod that started the reaction.

After the war, he supervised the decommissioning the Chicago Pile-1 reactor and became the director of the Argonne National Laboratory between 1946 and 1956. He also supervised the construction of several new nuclear reactors, including the Experimental Breeder Reactor I (EBR-I) in Idaho, USA. He served as chief scientific advisor on the design of the USS Nautilus, the first nuclear-powered submarine.

After leaving Argonne, he moved to Florida where he founded a consulting firm.

He received numerous awards and distinctions, including the Atoms for Peace Prize (1960) and the Enrico Fermi Prize (1969). He was also the first president of the American Nuclear Society.