Irénée du Pont, Jr. is a member of the storied du Pont family and the son of the President (1919 to 1925) of the E. I. du Pont de Nemours and Company. He is an engineer and worked for DuPont for many years.
The DuPont Company played a crucial role in the Manhattan Project; in 1942, DuPont was enlisted to design and build the project facilities at Hanford, including the B Reactor. Du Pont’s second oldest sister, Margaretta, married Crawford Greenewalt, a famous Manhattan Project scientist and chemical engineer who served as liaison between the Met Lab physicists and the DuPont engineers working on the B Reactor.