Dr. Clarence Larson, a chemist, began working under Ernest O. Lawrence in his lab at the University of California, Berkeley in 1942. In 1943, he moved to Oak Ridge and was appointed head of operations for Union Carbide. He later served as director of Oak Ridge National Laboratory and as a commissioner on the U.S. Atomic Energy Commission. During the Manhattan Project, Larson designed a process to recover and purify uranium deposits from the walls of calutron receivers at the Y-12 Plant. In this interview, he explains the importance of this innovation in producing enough enriched uranium for an atomic bomb. He also describes the challenges encountered in the Y-12 Plant’s early days, as well as Lawrence’s unyielding confidence.