Conclusion

The utilization of nuclear energy became possible firstly due to the discovery of radioactivity; the centenary of this breakthrough was celebrated by the international scientific community in 1996. Foundations for radioactivity studies and nuclear fission physics in the USSR were laid in the pre-war period by V . G . Khlopin, L .S . Kolovrat-Chervinskiy, G . A . Gamow, L . V . Mysovskiy, A . F . Ioffe, I.V. Kurchatov and many other scientists. Great scientific advances such as radium production and its use in medicine, nuclear physics, and radiochemistry, the construction of a first cyclotron at RIAN (first in Europe), and the discovery of uranium fission enabled Academician V . I . Vernadskiy to establish in 1940 a Uranium Commission at the USSR Academy of Sciences. In 1940-1941 this Commission proposed the first version of the State Program on the use of uranium fission energy. This program stipulated activities in the exploration and mining of uranium resources, appointed the leading research institutes responsible for the development of uranium isotope separation techniques, and proposed that some of the institutes should be provided with new experimental equipment to carry out research into the utilization of nuclear fission in the national economy. Just before the war, two young researchers, G . N . Flerov and K . A . Petrzhak, discovered a spontaneous (without neutron irradiation) fission of uranium. Two monographs published by the Leningrad physicists, one by theoretician G . A . Gamow, the other by experimenter I .V. Kurchatov, demonstrated the abilities of Soviet scientists to carry out fundamental research into nuclear fission. In 1939-1940, Ya.B. Zeldovich and Yu .B . Khariton calculated that a nuclear chain reaction could be obtained in a system consisting of uranium, slightly enriched with 2 3 5 U , and heavy hydrogen or graphite. They also specified conditions for a nuclear explosion and evaluated its demolition power. Information about the accumulation of considerable reserves of uranium in the USA and Germany and publications on the determination of the yield of secondary neutrons per primary neutron captured

258 History of the Soviet Atomic Industry

by a uranium nucleus (E. Fermi and F. Joliot-Curie in the West, G . N . Flerov and L.Ï. Rusinov in the Soviet Union) proved the reality of a nuclear chain reaction. After the beginning of the war, publications of this kind were banned in the West; in the USSR many of the researchers engaged in this field joined the Army; the leading research centers of Moscow and Leningrad were moved to the East, and research into the utilization of nuclear fission was suspended and renewed after getting intelligence data evidencing that Germany, U K and the United States were very active in the use of nuclear energy for military purposes. Activities of the Soviet intelligence which informed the government of secret nuclear research under way abroad was well organized. As early as mid-1943, scientific coordinator of the Uranium Project I .V. Kurchatov, in his report to M . G . Pervukhin, emphasized the great value of 237 documents on 2 3 9 P u and enriched 2 3 5 U production provided by the intelligence. This is how Academician Yu.B. Khariton evaluated intelligence information in his book [170]: "Intelligence helped our researchers to save time and avoid "fall flats" when conducting the first A-bomb test which was of great political significance. Our intelligence helped to make I .V. Kurchatov one of the most informed nuclear physicists in the world. Aware of the advances of his colleagues in the USSR, he at the same time was aware of the progress of Western scientists. This was of great importance in the initial stage of the nuclear weapons race." It should be noted that Kurchatov (given Pervukhin's authorization) had the right of showing these documents to his colleagues who were his deputies in particular areas of the Uranium Project. Intelligence data were of great value not only to nuclear physicists. They were equally important to scholars and designers of equipment and technologies for uranium isotope separation, uranium/graphite and heavy-water nuclear reactors fuelled with natural uranium, for the development of uranium metal, uranium hexafluoride, heavy-water production technologies, etc. Moreover, the intelligence provided documents on the bomb design. Naturally, Kurchatov understood that to evaluate these documents, he needed not only nuclear physicists but also experts in metallurgy and metal physics who worked with metal plutonium and uranium, experts in physical chemistry, and other researchers who headed particular areas of the Soviet atomic project. Therefore, not only Kurchatov himself, but I.K. Kikoin, Yu .B . Khariton A . A . Bochvar, L . A . Artsimovich and other leading scientists were well informed on the advances of their Western counterparts [102, 171). Nevertheless, as mentioned by the US researchers, scientific aspects were not key problems of any atomic project. In 1945, G. Smyth published his monograph Atomic Energy for Military Purposes (an official report of the US Government on the atomic bomb project) in the United States. This publication indicates that the US authorities were sure that because of great technical difficulties Soviet industry would not be able to start production of plutonium and enriched 2 3 5 U and build appropriate production facilities, and hence the USSR would not be able to develop an atomic bomb in less than 10 years 136]:

"Basic difficulties the Soviets have to overcome will be related to the current state of their heavy industry and production. The Soviet Union has brilliant scientists who are able to find answers to all the questions by themselves. Moreover, they got much help from the intelligence."