Soviet Espionage and Manhattan Project

Soviet atomic bomb project
From Wikipedia, the free encyclopedia.
Espionage
The project had the benefit of much espionage information gathered from the Manhattan Project in the United States and United Kingdom (which the Russians had code-named Enormoz) by the spies Alan Nunn May, Klaus Fuchs and Theodore Hall, among others. However, the information was not shared freely among the project's scientists, and was used by Beria as a "check" on the accuracy of the scientists. After the United States used its atomic weapons on Hiroshima and Nagasaki, Japan, in 1945, and published the Smyth Report outlining the basics of their wartime program, Beria had the scientists duplicate the American process as closely as possible in terms of development of resources and factories. The reason was expedience: the goal was to produce a working weapon as soon as possible, and after Hiroshima and Nagasaki they knew that the American design would work.
Scholar Alexei Kojevnikov has estimated, based on newly released Soviet documents, that the primary way in which the espionage may have sped up the Soviet project was that it allowed Khariton to avoid dangerous tests to determine the size of the critical mass ("tickling the dragon's tail," as they were called in the U.S., which consumed a good deal of time and claimed at least two lives).
Logistical problems the Soviets faced
The single largest problem during the early Soviet project was the procurement of uranium ore, as it had no known domestic sources at the beginning of the project. The first Soviet nuclear reactor was fueled using uranium confiscated from the remains of the German atomic bomb project. Eventually, however, large domestic sources were found, and mined using penal labor.