The person who was in charge of all scientific experiments and procedures related to the development of the atomic weapon was J. Robert Oppenheimer. He was given the job in 1942 by the project director, Leslie Groves.
Oppenheimer never worked at Hanford. In fact, Oppenheimer was responsible for the selection of Los Alamos, New Mexico, as the place where plutonium produced at Hanford would be placed into the atomic bombs for use in World War II. Los Alamos, like Hanford, was another top secret facility. Starting in late 1942, while scientists and engineers at Hanford were busy building nuclear reactors to produce the plutonium, Oppenheimer’s team was doing work at Los Alamos as well. Their job was to make sure that when the plutonium did arrive, the bomb that needed it would be ready to be used shortly after that.
After nearly two years, enough Hanford plutonium had been taken to Los Alamos for a test of the new atomic weapon to be held. Under Oppenheimer’s direction, this plutonium was put inside a test bomb that was placed in a remote part of the New Mexico Desert. With many of the important people who had been working on making an atomic bomb watching from a safe location, the world’s first atomic bomb was detonated. Called the Trinity Test, the explosion proved that atomic bombs would work, and could be used in World War II.
With the success of the Trinity Test, President Harry Truman decided to proceed with plans to drop an atomic weapon on Japan. On August 6, 1945, the first atomic bomb, called “Little Boy”, was exploded over the city of Hiroshima, Japan. Three days later, the second atomic bomb called “Fat Man”, which included plutonium produced at Hanford, was blown up over the city of Nagasaki, Japan. World War II ended a few days later.