— Ch. 1 · The Letters That Changed History —
Soviet atomic bomb project.
~5 min read · Ch. 1 of 5
In April 1942, physicist Georgy Flyorov sent two classified letters to Soviet leader Joseph Stalin. The first letter warned that Western scientists had stopped publishing on nuclear science because they were secretly building atomic weapons. Flyorov wrote that the results of such a weapon would be so overriding that it would not matter who was blamed for neglecting this work in their own country. A second letter from Flyorov and Konstantin Petrzhak emphasized the urgent need to manufacture a uranium bomb without delay.
Stalin read these letters and immediately pulled Soviet physicists from military service to start an atomic program. He authorized engineering physicist Anatoly Alexandrov and nuclear physicist Igor Kurchatov to lead the effort. Laboratory No. 2 near Moscow became the new home for this research. Abram Ioffe had refused the post due to his age but recommended the younger Kurchatov instead. Kurchatov felt awed by the magnitude of the task yet remained unconvinced about its utility against the demands of the Eastern Front war.
By late 1942, the State Defense Committee officially delegated the entire program to the Soviet Army. Lavrentiy Beria, head of the NKVD, later supervised major wartime logistical efforts. Flyorov himself moved to Dubna where he established the Laboratory of Nuclear Reactions. This facility focused on synthetic elements and thermal reactions while Kurchatov's team worked on the main bomb design.
Spies And The Manhattan Secret
Soviet intelligence obtained rough blueprints of the first United States atomic device during 1945. American communist sympathizers controlled by Russian officials in North America shared classified information that greatly aided the speed of the Soviet nuclear program between 1942 and 1954. Harry Gold served as a key operative who received sensitive atomic information from British physicist Klaus Fuchs. Theodore Hall provided theoretical physics data directly to Soviet handlers.
Kurchatov told Foreign Minister Vyacheslav Molotov that the materials were magnificent because they added exactly what had been missing from their own research. Richard Rhodes noted that Kurchatov learned enough through espionage to transform the Soviet program and accelerate it by a full two years. This included an alternative approach using Plutonium-239 instead of uranium isotope separation. The espionage material also made them include diffusion experiments alongside centrifuge technology in their plans.
The Soviets avoided dangerous tests known as tickling the dragon's tail which consumed time and claimed at least two lives in the American program. These tests involved Harry Daghlian and Louis Slotin. The published Smyth Report of 1945 on the Manhattan Project was translated into Russian. Translators noticed a sentence about poisoning of Plutonium-239 deleted from later editions alerted the Soviet Union to reactor-bred plutonium problems.