Background origins and roots

As early as 1910 in Russia, independent research was being conducted on radioactive elements by several Russian scientists.[12]:44[13]:24–25 Despite the hardship faced by the Russian academy of sciences during the national revolution in 1917, followed by the violent civil war in 1922, the Russian scientists had made remarkable efforts towards the advancement of physics research in the Soviet Union in the 1930s.[14]:35–36 Before the first revolution in 1905, the mineralogist Vladimir Vernadsky had made a number of public calls for a survey of Russia's uranium deposits but none were heeded.[14]:37

However, such early efforts were independently and privately funded by various organizations until 1922 when the Radium Institute in Petrograd (now Saint Petersburg) opened and industrialized the research.:44[12]

From the 1920s until the late 1930s, Russian physicists had been conducting joint research with their European counterparts on the advancement of atomic physics at the Cavendish Laboratory run by a New Zealand physicist, Ernest Rutherford, where Georgi Gamov and Pyotr Kapitsa had studied and researched.[14]:36

Influential research towards the advancement of nuclear physics was guided by Abram Ioffe, who was the director at the Leningrad Physical-Technical Institute (LPTI), having sponsored various research programs at various technical schools in the Soviet Union.[14]:36 The discovery of the neutron by the British physicist James Chadwick further provided promising expansion of the LPTI's program, with the operation of the first cyclotron to energies of over 1 MeV, and the first "splitting" of the atomic nucleus by John Cockcroft and Ernest Walton.[14]:36–37 Russian physicists began pushing the government, lobbying in the interest of the development of science in the Soviet Union, which had received little interest due to the upheavals created during the Russian revolution and the February Revolution.[14]:36–37 Earlier research was directed towards the medical and scientific exploration of radium; a supply of it was available as it could be retrieved from borehole water from the Ukhta oilfields.[14]:37

In 1939, German chemist Otto Hahn reported his discovery of fission, achieved by the splitting of uranium with neutrons that produced the much lighter element barium. This eventually led to the realization among Russian scientists, and their American counterparts, that such reaction could have military significance.[15]:20 The discovery excited the Russian physicists, and they began conducting their independent investigations on nuclear fission, mainly aiming towards power generation, as many were skeptical of possibility of creating an atomic bomb anytime soon.[16]:25 Early efforts were led by Yakov Frenkel (a physicist specialised on condensed matter), who did the first theoretical calculations on continuum mechanics directly relating the kinematics of binding energy in fission process in 1940.[15]:99 Georgy Flyorov's and Lev Rusinov's collaborative work on thermal reactions concluded that 3-1 neutrons were emitted per fission only days after similar conclusions had been reached by the team of Frédéric Joliot-Curie.[15]:63[17]:200

World War II and accelerated feasibility

After a strong lobbying of Russian scientists, the Soviet government initially set up a commission that was to address the "uranium problem" and investigate the possibility of chain reaction and isotope separation.[18]:33 The Uranium Problem Commission was ineffective because the German invasion of Soviet Union eventually limited the focus on research, as Russia became engaged in a bloody conflict along the Eastern Front for the next four years.[19]:114–115[20]:200 The Soviet atomic weapons program had no significance, and most work was unclassified as the papers were continuously published as public domain in academic journals.[18]:33

Joseph Stalin, the Soviet leader, had mostly disregarded the atomic knowledge possessed by the Russian scientists and had most of the scientists working in the metallurgy and mining industry or serving in the Soviet Armed Forces technical branches during the World War II's eastern front in 1940–42.[21]:xx

In 1940–42, Georgy Flyorov, a Russian physicist serving as an officer in the Soviet Air Force, noted that despite progress in other areas of physics, the German, British, and American scientists had ceased publishing papers on nuclear science. Clearly, they each had active secret research programs.[22]:230 The dispersal of Soviet scientists had sent Abram Ioffe’s Radium Institute from Leningrad to Kazan; and the wartime research program put the "uranium bomb" programme third, after radar and anti-mine protection for ships. Kurchatov had moved from Kazan to Murmansk to work on mines for the Soviet Navy.[23]

In April 1942, Flyorov directed two classified letters to Stalin, warning him of the consequences of the development of atomic weapons: "the results will be so overriding [that] it won't be necessary to determine who is to blame for the fact that this work has been neglected in our country."[24]:xxx The second letter, by Flyorov and Konstantin Petrzhak, highly emphasized the importance of a "uranium bomb": "it is essential to manufacture a uranium bomb without a delay."[22]:230

Upon reading the Flyorov letters, Stalin immediately pulled Russian physicists from their respective military services and authorized an atomic bomb project, under engineering physicist Anatoly Alexandrov and nuclear physicist Igor V. Kurchatov.[22]:230[21]:xx For this purpose, the Laboratory No. 2 near Moscow was established under Kurchatov.[22]:230 Kurchatov was chosen in late 1942 as the technical director of the Soviet bomb program; he was awed by the magnitude of the task but was by no means convinced of its utility against the demands of the front.[23] Abram Ioffe had refused the post as he was too old, and recommended the young Kurchatov.

At the same time, Flyorov was moved to Dubna, where he established the Laboratory of Nuclear Reactions, focusing on synthetic elements and thermal reactions.[21]:xx In late 1942, the State Defense Committee officially delegated the program to the Soviet Army, with major wartime logistical efforts later being supervised by Lavrentiy Beria, the head of NKVD.[19]:114–115

In 1945, the Arzamas 16 site, near Moscow, was established under Yakov Zel'dovich and Yuli Khariton who performed calculations on nuclear combustion theory, alongside Isaak Pomeranchuk.[25]:117–118 Despite early and accelerated efforts, it was reported by historians that efforts on building a bomb using weapon-grade uranium seemed hopeless to Russian scientists.[25]:117–118 Igor Kurchatov had harboured doubts working towards the uranium bomb, but made progress on a bomb using weapon-grade plutonium after British data was provided by the NKVD.[25]:117–118

The situation dramatically changed when the Soviet Union learned of the atomic bombings of Hiroshima and Nagasaki in 1945.[26]:2–5

Immediately after the atomic bombing, the Soviet Politburo took control of the atomic bomb project by establishing a special committee to oversee the development of nuclear weapons as soon as possible.[26]:2–5 On 9 April 1946, the Council of Ministers created KB–11 ('Design Bureau-11') that worked towards mapping the first nuclear weapon design, primarily based on the American approach and detonated with weapon-grade plutonium.[26]:2–5 From then on work on the program was carried out quickly, resulting in the first nuclear reactor near Moscow on 25 October 1946.[26]:2–5