A friend, Betty Lilienthal, told The Santa Fe New Mexican Duffield was "the perfect secretary and Oppenheimer's right hand." Duffield knew a lot of secrets and never talked about them, Lilienthal said.
Duffield died of natural causes July 21 at her home in Norwood.
Duffield was born Priscilla Greene in California and graduated from the University of California at Berkeley. In 1943, she became secretary to E.O. Lawrence at what is now known as the Lawrence Berkeley National Laboratory.
Oppenheimer started by borrowing her from Lawrence and offered her the post as his secretary at Los Alamos.
Duffield met her husband, who died in 2000, at Los Alamos. She later described the years there as the best in her life and called Oppenheimer, who led the Manhattan Project in creating the world's first atomic bomb, a "considerate and smart man."
In the 1960s and 1970s, Duffield worked for other well-known scientists at the Scripps Institution of Oceanography and the Fermi National Accelerator Laboratory.