John Attanas was born in 1920 and grew up on farm near Kingston, New York. After graduating from Georgia Tech in 1942 with a degree in chemical engineering, he worked in a chemistry lab at the Remington Arms Company.
After the Manhattan Project began, Attanas worked for DuPont at Oak Ridge, Tennessee, researching plutonium extraction methods. His first wife, Mary Rita Lilli, accompanied him there.
Less than a year after arriving in Oak Ridge, Attanas transferred to Hanford, WA, where he worked in the 200 East Area as a supervisor. He and his wife lived in Richland.
On July 16, 1945, Attanas witnessed the Trinity Test. After the war, he worked for the Air Force in Ohio before returning to New York State to work on semiconductors for General Electric.