These methods were used during the preparation of plutonium-239 , the fissile material used in the construction of the atomic bomb for the Trinity nuclear test , on July 16 , 1945 . Analogous methods were used for the uranium weapon , code-named " Little Boy " , which destroyed Hiroshima , Japan on August 6 , 1945 , and for the plutonium bomb which destroyed Nagasaki , Japan on August 9 , 1945 , leading to the Japanese surrender . The secret program was under the general direction of J. Robert Oppenheimer , whom Bachelder described as : The conclusion of the Second World War was also the dawning of a new " Atomic Age " , in which the peacetime potential of nuclear energy began to be explored . Bachelder was among the scientists who opposed the May-Johnson Bill of October 1945 , a Congressional bill proposed by the Interim Committee , which would have maintained military control over nuclear research . The bill was defeated in Congress and superseded by the McMahon Atomic Energy Act . In January 1947 , the newly formed Atomic Energy Commission approved the declassification of 270 previously secret documents . These included discoveries related to X-radiation and purification of uranium ores , which had been made by Bachelder during the course of the war effort . At this time , the rarity and importance of Bachelder 's achievements as a woman in science were also acknowledged
Trinity nuclear test
Trinity (nuclear test)
Myrtle Bachelder