The Soviet Union did not keep a record of the Soviet atomic project, even of the major events, so there is very little information known about this topic. As it was a regime with strict secrecy, only a few of the top leaders knew of the events on the atomic bomb project. Most of the people who worked on this project have died, so it is really difficult to find out about the project. Much of what we know about the project is through memoirs of the people working on the project, but these occasionally contain some inaccuracies. But it is known that the first Soviet bomb was built with the help of a spy, Klaus Fuchs.
Klaus Fuchs was born on December 29, 1911 in Russelsheim, Germany. He was a Communist, and the Communist Party in Germany sent him out of Germany to Britain, saying that after the revolution against Hitler's Nazi Party, people with technical knowledge would be required to built a new Communist state in Germany.
In Britain, Fuchs proved to be a brilliant scientist and earned a PhD in physics from the University of Bristol. He was then chosen to work in Edinburgh with the pioneers of quantum mechanics. After the Second World War broke out, the British chose him to work on the development of the atom bomb, although knowing of his Communist past. Fuchs took part.
He says he when he was recruited he knew he would have to work "on some war work. I accepted it and started work without knowing at first what the work was... When I learned the purpose of the work I decided to inform Russia and I established contact through another member of the Communist Party."
In 1943 Fuchs was sent to the United States to work...