Donald Ross worked on the Manhattan Project at the University of California-Berkeley and the Y-12 Plant for Tennessee Eastman. In this interview, Ross discusses supervising “Calutron girls” at Y-12. He explains how the electromagnetic separation process for separating uranium isotopes work, and recalls the tight security at Oak Ridge. Ross also describes the social life at Oak Ridge, meeting his wife, and the terrible food in the mess halls. He discusses his views on dropping the bomb on Japan and how his thoughts have changed over time.