 The Director of the Manhattan Project, Brigadier General Leslie R. Groves, Jr., had, in November 1942, recruited DuPont as the prime contractor for the construction of a plutonium production complex.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 of heavy water would be required per month.