Primer: The Soviet Bomb

The early history of the atomic bomb is necessarily a part of the history of physics, because in less than a decade what was an entirely novel physical phenomenon—the splitting of certain atomic nuclei when struck by neutrons—had been engineered into a military weapon with unprecedented destructive power.

The key  experiments had been conducted in Germany at the end of 1938, but once the mechanism had been interpreted by Lise Meitner and Otto Frisch (both of whom had fled the Nazis), its implications were appreciated across the world of nuclear physics, including in the Soviet Union.

Like the United States, the Soviet Union was not a traditional leader in physics, but, like the United States, the physics community was respected and had a burgeoning nuclear physics community.  This community, like others across the world, fully recognized the implications of nuclear fission before nuclear research went secret after the war began, and members of it played a leading role in the research and development of nuclear weaponry and energy.

During the war, because the Soviet Union quickly became embroiled in an epic ground war with the Nazis, Soviet nuclear research did not receive as strong a priority as it ultimately did in the United States, though a research project was established in the winter of 1942-43 once it was learned from spies that the Germans, British, and Americans had established their own programs.  The research work was centered at a laboratory near Moscow, directed by Igor Kurchatov (1903-1960) of the Physical-Technical Institute in Leningrad, and administered by Lavrentii Beria (1899-executed in 1953), a central figure in the Communist Party who was known for both his effective managerial skills and his ruthlessness.  Kurchatov and Beria would remain in charge of the postwar project.

While the war lasted, research remained exploratory, working out such essential problems as whether nuclear fission chain reactions were sustainable, how an explosive chain reaction would work, and how to separate fissile uranium isotopes from raw uranium.  Like the German effort, the Soviet effort did not produce a reactor.  However, after the American use of their atomic bomb at Hiroshima, the project was lifted to top priority.  A substantial research facility called Arzamas-16 (sometimes referred to as “Los Arzamas”) was established 400 km east of Moscow, with physicist Iulii Khariton (1904-1996) becoming its scientific director—a position he would hold until 1992.  Employing conscripted and prisoner labor, the Soviets also rapidly assembled a large nuclear industry, which could mine uranium, purify it, create plutonium in reactors, and, ultimately assemble bombs.

Both during the war and after, Soviet research was guided by information obtained by espionage.  While information received had to be verified as correct, and substantial further R&D still had to be conducted by Soviet physicists and engineers to construct working technologies, the research directors of the project knew what development routes the Americans had found successful.  While some project scientists, reminded of their traditional role as followers of western science, were eager to explore research angles more thoroughly, political pressure to complete a bomb quickly kept research on the track laid out by American efforts.

The first activation of a Soviet reactor took place on December 25, 1946.  The first Soviet bomb was detonated on August 29, 1949, relieving the enormous political pressure on project scientists to complete their work successfully.  While the Americans had completed two bomb designs by August 1945—a uranium-based bomb and a bomb based on plutonium created in reactors—the Soviets would not have the capability to purify the uranium-235 isotope for another year, and so their first bomb was based on the American plutonium model.

Meanwhile, just as the American Manhattan Project had dedicated an effort under Edward Teller to developing a design theory for a bomb on the order of 1,000 times the power of an ordinary atomic bomb, based on the fusion of hydrogen nuclei—the “hydrogen” or “super” bomb—so did the Soviets, beginning in 1946.  Full-scale development of a hydrogen bomb program commenced in 1948 in both the United States and the Soviet Union.  In the Soviet Union, theoretical design was led by Igor Tamm (1895-1971), based on a design proposal from Andrei Sakharov (1921-1989), whom Tamm had recruited to the project, and who would later become better known as a dissident.

The first American test of a hydrogen bomb took place on November 1, 1952 at Eniwetok atoll in the South Pacific.  The Soviet test took place on August 12, 1953.  Both the United States and the Soviet Union (and other nations, beginning with Britain) would continue to develop and test new generations of nuclear weapons.  Kurchatov would leave the Soviet nuclear weapons program after the first hydrogen bomb test to exceed a megaton in strength in 1955.

The history of the American bomb has been heavily influenced by the moral ambivalence surrounding bomb development, particularly as it has related to wider discussions concerning the moral responsibilities of scientists.  Soviet physicists were not generally disturbed by their work, seeing it as necessary to maintain the military strength of their country.  Although they often felt political pressure from the Stalinist regime, nuclear work also offered political protection and reward, especially in the wake of successes.  While the initial full-scale effort followed on the American use of the bomb at Hiroshima, subsequent development largely occurred on the basis of its own momentum, and not in reaction to the progress of the American project.

This post is based on David Holloway’s methodical and superbly researched and written Stalin and the Bomb (1994).  See also the PBS web exhibit, Citizen Kurchatov.