National Museum of Nuclear Science & History
L. A. Castellanos worked for the J.A. Jones Construction Company.
Jack Hefner joined the Manhattan Project at Oak Ridge in 1943. Hefner was a reactor engineer and helped supervise the construction of the X-10 Graphite Reactor.
Julian Mack was an American physicist. Mack was the leader of Group G-11 (Optics), the photography group, in the Weapons Physics Division at Los Alamos during the Manhattan Project.
