Koval was transferred from Oak Ridge to a top-secret lab in Dayton, Ohio on June 27, 1945, where polonium initiators were fabricated. The world's first atomic bomb was detonated in New Mexico on July 16 of that year. Atomic bombs were dropped on Japan on August 6 and 9, leading to Japan's surrender and the end of World War II. The Soviet Union responded by increasing efforts to develop its own atomic bomb. While the American Central Intelligence Agency estimated the Soviets would not succeed until 1950–53, the first Soviet atomic bomb was detonated on August 29, 1949. The initiator for the plutonium bomb was, according to Russian military officials, "prepared to the 'recipe' provided by military intelligence agent Delmar [Koval]".