The Manhattan Project

In partnership with the National Museum of Nuclear Science & HistoryNational Museum of Nuclear Science & History

Oral Histories

Robert Holmberg's Interview

Robert Holmberg's Interview

Robert Holmberg began working on the Manhattan Project at the Chicago Met Lab and at Ames Laboratory in Iowa. He was then drafted into the Special Engineer Detachment and sent to Oak Ridge. He describes his life at Oak Ridge, where he met his wife and settled down, and recalls what he and his colleagues thought of General Leslie Groves at the time.

Hank Kosmata's Interview

Hank Kosmata's Interview

Hank Kosmata arrived in Hanford in January 1954 after graduating from the University of Utah with a degree in chemical engineering. After helping with the construction of K Reactor, Kosmata worked with “Reactor Design Analysis,” a team of physicists, mathematicians, and mechanical engineers that were tasked with designing a new, re-circulating reactor. After a year of planning, Kosmata and his team finalized the basis of what would become the “New Production Reactor,” or N Reactor. Kosmata discusses some of the similarities and differences of the design of N Reactor with that of B Reactor. He also explains that the development of N Reactor could not have been possible without the information and experience of those who worked on the B Reactor during the Manhattan Project. He talks about the role of nuclear power in the world today.

Haskell Sheinberg's Interview

Haskell Sheinberg's Interview

Haskell Sheinberg arrived at Los Alamos in late 1944 as part of the Special Engineer Detachment. Sheinberg’s first assignment was to purify plutonium under the direction of Arthur Wahl, one of the co-discoverers of plutonium. Sheinberg discusses the safety procedures the laboratory had in place to protect its workers from the harmful effects of radiation and also recalls attending several of Oppenheimer’s colloquiums regarding the overall progress of the Manhattan Project. He remembers meeting his wife, who worked in the Women’s Auxiliary Corps and received a commendation from Oppenheimer for her technical work, at one of the dances at the Los Alamos recreation hall. Sheinberg had a long and storied career at the Los Alamos National Laboratory.

Darrell Dvorak

Darrell Dvorak's Interview

Darrell Dvorak’s father-in-law, Colonel Clifford John Heflin, worked for the Manhattan Project. Dvorak became interested in Heflin’s life following his passing and has published several papers on Heflin’s war work. Col. Heflin organized the top-secret unit known as the “Carpetbaggers,” commanding their missions dropping supplies, arms to the resistance movement, landing behind enemy lines. Based on the strength of his work with the Carpetbaggers, Col. Heflin was selected as the Commanding Officer of Wendover Air Base, overseeing the management of the base as well as the ordnance and ballistics work. Dvorak discusses the relationship between Col. Heflin and Col. Tibbets and the military hierarchy at Wendover, explaining that Tibbets and Heflin represented two separate chains of command, and talks about why Heflin’s important role in the Manhattan Project has been overlooked for so long.

Catherine Dvorak's Interview

Catherine Dvorak's Interview

Cathy Dvorak’s father, Colonel Clifford Heflin, was selected as the Commanding Officer of Wendover Air Base, overseeing the management of the base as well as the ordnance and ballistics work. Dvorak first learned of her father’s involvement with the Manhattan Project when she was a teenager. Dvorak states that Col. Heflin gave only one interview concerning his work with the Manhattan Project, after his retirement from the Air Force. Dvorak shares stories about Col. Heflin as a family man.

Bob Kupp

Robert Kupp's Interview

Robert Kupp received mysterious orders to report to Knoxville, Tennessee just before he was shipped out to the Pacific Theater, and joined the Manhattan Project at Oak Ridge. He was assigned to work as a supervisor in the Line Recorder Department at the K-25 Plant. He discusses life at Oak Ridge and the security and secrecy involved in working on the project. Kupp went on to a prestigious career as a nuclear engineer.

Ken Pumphrey Final Cut

Kenneth Pumphrey's Interview

Ken Pumphrey worked as a security guard for the Special Engineer Detachment in Los Alamos from 1946-1948. Pumphrey recalls his part in securing the secret city and rotating around Los Alamos on guard duty. He was one of the last 12 military personnel to leave Los Alamos before the area was turned over to civilian administration. Pumphrey talks about getting treated at the hospital, the military hierarchy, and his family’s suspicion over his odd PO Box mailing address.

Richard Renner's Interview

Richard Renner's Interview

Richard Renner arrived in Los Alamos shortly after being drafted into the Special Engineer Detachment in 1945, after the war had ended. Renner worked as a firefighter at Los Alamos, stationed by the top-secret S-Site, where bombs were assembled. Renner recalls how his experiences in Santa Fe influenced his passion for Latin American studies. Renner later worked as a Professor at the University of Florida.

Dunell Cohn

Dunell Cohn's Interview

Dunell Cohn was born in Oak Ridge in 1944. Cohn’s father, Waldo, was recruited to work on the Manhattan Project in Chicago in 1942 for his work on radioisotopes at Berkeley and Harvard during the 1930s. Shortly thereafter, he was transferred to Oak Ridge, where he developed a method to separate the fission products from the nuclear reactor. He also pioneered the radioisotope program at Oak Ridge, producing radioisotopes in large quantities that could then be used for medical and biological research. Dunell recalls what it was like growing up as a child at Oak Ridge and describes his father’s effort to desegregate the town by integrating the public school system. He also remembers his father’s love for music and his role in creating Oak Ridge’s symphony orchestra.

Dolores Heaton's Interview

Dolores Heaton's Interview

Dolores Heaton’s father worked on the Manhattan Project at Los Alamos, and she arrived at Los Alamos with her family as a young girl. Heaton recalls what it was like growing up in Los Alamos as a child. With the housing shortage present there, Heaton and her family lived in Quonset huts and were subjected to rationing. Heaton also shares her memories of eating sandwiches with J. Robert Oppenheimer and growing up with the children of the famous scientists working on the Manhattan Project. She talks about the diversity of her school, the first-class education she received, and why Los Alamos was truly a unique town to be raised in.

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